1754 lines
44 KiB
ArmAsm
1754 lines
44 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* OpenRISC head.S
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*/
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#include <linux/linkage.h>
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#include <linux/threads.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/serial_reg.h>
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#include <linux/pgtable.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <asm/mmu.h>
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#include <asm/thread_info.h>
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#include <asm/cache.h>
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#include <asm/spr_defs.h>
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#include <asm/asm-offsets.h>
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#include <linux/of_fdt.h>
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#define tophys(rd,rs) \
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l.movhi rd,hi(-KERNELBASE) ;\
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l.add rd,rd,rs
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#define CLEAR_GPR(gpr) \
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l.movhi gpr,0x0
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#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
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l.movhi gpr,hi(symbol) ;\
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l.ori gpr,gpr,lo(symbol)
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#define UART_BASE_ADD 0x90000000
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#define EXCEPTION_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_SM)
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#define SYSCALL_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_DCE | SPR_SR_ICE | SPR_SR_IEE | SPR_SR_TEE | SPR_SR_SM)
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/* ============================================[ tmp store locations ]=== */
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#define SPR_SHADOW_GPR(x) ((x) + SPR_GPR_BASE + 32)
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/*
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* emergency_print temporary stores
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*/
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#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
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#define EMERGENCY_PRINT_STORE_GPR4 l.mtspr r0,r4,SPR_SHADOW_GPR(14)
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#define EMERGENCY_PRINT_LOAD_GPR4 l.mfspr r4,r0,SPR_SHADOW_GPR(14)
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#define EMERGENCY_PRINT_STORE_GPR5 l.mtspr r0,r5,SPR_SHADOW_GPR(15)
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#define EMERGENCY_PRINT_LOAD_GPR5 l.mfspr r5,r0,SPR_SHADOW_GPR(15)
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#define EMERGENCY_PRINT_STORE_GPR6 l.mtspr r0,r6,SPR_SHADOW_GPR(16)
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#define EMERGENCY_PRINT_LOAD_GPR6 l.mfspr r6,r0,SPR_SHADOW_GPR(16)
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#define EMERGENCY_PRINT_STORE_GPR7 l.mtspr r0,r7,SPR_SHADOW_GPR(7)
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#define EMERGENCY_PRINT_LOAD_GPR7 l.mfspr r7,r0,SPR_SHADOW_GPR(7)
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#define EMERGENCY_PRINT_STORE_GPR8 l.mtspr r0,r8,SPR_SHADOW_GPR(8)
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#define EMERGENCY_PRINT_LOAD_GPR8 l.mfspr r8,r0,SPR_SHADOW_GPR(8)
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#define EMERGENCY_PRINT_STORE_GPR9 l.mtspr r0,r9,SPR_SHADOW_GPR(9)
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#define EMERGENCY_PRINT_LOAD_GPR9 l.mfspr r9,r0,SPR_SHADOW_GPR(9)
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#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
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#define EMERGENCY_PRINT_STORE_GPR4 l.sw 0x20(r0),r4
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#define EMERGENCY_PRINT_LOAD_GPR4 l.lwz r4,0x20(r0)
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#define EMERGENCY_PRINT_STORE_GPR5 l.sw 0x24(r0),r5
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#define EMERGENCY_PRINT_LOAD_GPR5 l.lwz r5,0x24(r0)
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#define EMERGENCY_PRINT_STORE_GPR6 l.sw 0x28(r0),r6
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#define EMERGENCY_PRINT_LOAD_GPR6 l.lwz r6,0x28(r0)
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#define EMERGENCY_PRINT_STORE_GPR7 l.sw 0x2c(r0),r7
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#define EMERGENCY_PRINT_LOAD_GPR7 l.lwz r7,0x2c(r0)
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#define EMERGENCY_PRINT_STORE_GPR8 l.sw 0x30(r0),r8
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#define EMERGENCY_PRINT_LOAD_GPR8 l.lwz r8,0x30(r0)
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#define EMERGENCY_PRINT_STORE_GPR9 l.sw 0x34(r0),r9
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#define EMERGENCY_PRINT_LOAD_GPR9 l.lwz r9,0x34(r0)
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#endif
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/*
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* TLB miss handlers temorary stores
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*/
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#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
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#define EXCEPTION_STORE_GPR2 l.mtspr r0,r2,SPR_SHADOW_GPR(2)
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#define EXCEPTION_LOAD_GPR2 l.mfspr r2,r0,SPR_SHADOW_GPR(2)
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#define EXCEPTION_STORE_GPR3 l.mtspr r0,r3,SPR_SHADOW_GPR(3)
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#define EXCEPTION_LOAD_GPR3 l.mfspr r3,r0,SPR_SHADOW_GPR(3)
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#define EXCEPTION_STORE_GPR4 l.mtspr r0,r4,SPR_SHADOW_GPR(4)
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#define EXCEPTION_LOAD_GPR4 l.mfspr r4,r0,SPR_SHADOW_GPR(4)
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#define EXCEPTION_STORE_GPR5 l.mtspr r0,r5,SPR_SHADOW_GPR(5)
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#define EXCEPTION_LOAD_GPR5 l.mfspr r5,r0,SPR_SHADOW_GPR(5)
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#define EXCEPTION_STORE_GPR6 l.mtspr r0,r6,SPR_SHADOW_GPR(6)
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#define EXCEPTION_LOAD_GPR6 l.mfspr r6,r0,SPR_SHADOW_GPR(6)
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#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
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#define EXCEPTION_STORE_GPR2 l.sw 0x64(r0),r2
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#define EXCEPTION_LOAD_GPR2 l.lwz r2,0x64(r0)
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#define EXCEPTION_STORE_GPR3 l.sw 0x68(r0),r3
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#define EXCEPTION_LOAD_GPR3 l.lwz r3,0x68(r0)
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#define EXCEPTION_STORE_GPR4 l.sw 0x6c(r0),r4
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#define EXCEPTION_LOAD_GPR4 l.lwz r4,0x6c(r0)
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#define EXCEPTION_STORE_GPR5 l.sw 0x70(r0),r5
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#define EXCEPTION_LOAD_GPR5 l.lwz r5,0x70(r0)
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#define EXCEPTION_STORE_GPR6 l.sw 0x74(r0),r6
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#define EXCEPTION_LOAD_GPR6 l.lwz r6,0x74(r0)
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#endif
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/*
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* EXCEPTION_HANDLE temporary stores
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*/
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#ifdef CONFIG_OPENRISC_HAVE_SHADOW_GPRS
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#define EXCEPTION_T_STORE_GPR30 l.mtspr r0,r30,SPR_SHADOW_GPR(30)
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#define EXCEPTION_T_LOAD_GPR30(reg) l.mfspr reg,r0,SPR_SHADOW_GPR(30)
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#define EXCEPTION_T_STORE_GPR10 l.mtspr r0,r10,SPR_SHADOW_GPR(10)
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#define EXCEPTION_T_LOAD_GPR10(reg) l.mfspr reg,r0,SPR_SHADOW_GPR(10)
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#define EXCEPTION_T_STORE_SP l.mtspr r0,r1,SPR_SHADOW_GPR(1)
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#define EXCEPTION_T_LOAD_SP(reg) l.mfspr reg,r0,SPR_SHADOW_GPR(1)
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#else /* !CONFIG_OPENRISC_HAVE_SHADOW_GPRS */
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#define EXCEPTION_T_STORE_GPR30 l.sw 0x78(r0),r30
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#define EXCEPTION_T_LOAD_GPR30(reg) l.lwz reg,0x78(r0)
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#define EXCEPTION_T_STORE_GPR10 l.sw 0x7c(r0),r10
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#define EXCEPTION_T_LOAD_GPR10(reg) l.lwz reg,0x7c(r0)
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#define EXCEPTION_T_STORE_SP l.sw 0x80(r0),r1
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#define EXCEPTION_T_LOAD_SP(reg) l.lwz reg,0x80(r0)
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#endif
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/* =========================================================[ macros ]=== */
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#ifdef CONFIG_SMP
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#define GET_CURRENT_PGD(reg,t1) \
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LOAD_SYMBOL_2_GPR(reg,current_pgd) ;\
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l.mfspr t1,r0,SPR_COREID ;\
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l.slli t1,t1,2 ;\
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l.add reg,reg,t1 ;\
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tophys (t1,reg) ;\
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l.lwz reg,0(t1)
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#else
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#define GET_CURRENT_PGD(reg,t1) \
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LOAD_SYMBOL_2_GPR(reg,current_pgd) ;\
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tophys (t1,reg) ;\
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l.lwz reg,0(t1)
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#endif
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/* Load r10 from current_thread_info_set - clobbers r1 and r30 */
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#ifdef CONFIG_SMP
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#define GET_CURRENT_THREAD_INFO \
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LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\
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tophys (r30,r1) ;\
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l.mfspr r10,r0,SPR_COREID ;\
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l.slli r10,r10,2 ;\
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l.add r30,r30,r10 ;\
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/* r10: current_thread_info */ ;\
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l.lwz r10,0(r30)
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#else
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#define GET_CURRENT_THREAD_INFO \
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LOAD_SYMBOL_2_GPR(r1,current_thread_info_set) ;\
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tophys (r30,r1) ;\
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/* r10: current_thread_info */ ;\
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l.lwz r10,0(r30)
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#endif
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/*
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* DSCR: this is a common hook for handling exceptions. it will save
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* the needed registers, set up stack and pointer to current
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* then jump to the handler while enabling MMU
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*
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* PRMS: handler - a function to jump to. it has to save the
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* remaining registers to kernel stack, call
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* appropriate arch-independant exception handler
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* and finaly jump to ret_from_except
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*
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* PREQ: unchanged state from the time exception happened
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*
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* POST: SAVED the following registers original value
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* to the new created exception frame pointed to by r1
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*
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* r1 - ksp pointing to the new (exception) frame
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* r4 - EEAR exception EA
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* r10 - current pointing to current_thread_info struct
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* r12 - syscall 0, since we didn't come from syscall
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* r30 - handler address of the handler we'll jump to
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*
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* handler has to save remaining registers to the exception
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* ksp frame *before* tainting them!
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*
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* NOTE: this function is not reentrant per se. reentrancy is guaranteed
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* by processor disabling all exceptions/interrupts when exception
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* accours.
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*
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* OPTM: no need to make it so wasteful to extract ksp when in user mode
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*/
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#define EXCEPTION_HANDLE(handler) \
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EXCEPTION_T_STORE_GPR30 ;\
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l.mfspr r30,r0,SPR_ESR_BASE ;\
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l.andi r30,r30,SPR_SR_SM ;\
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l.sfeqi r30,0 ;\
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EXCEPTION_T_STORE_GPR10 ;\
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l.bnf 2f /* kernel_mode */ ;\
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EXCEPTION_T_STORE_SP /* delay slot */ ;\
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1: /* user_mode: */ ;\
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GET_CURRENT_THREAD_INFO ;\
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tophys (r30,r10) ;\
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l.lwz r1,(TI_KSP)(r30) ;\
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/* fall through */ ;\
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2: /* kernel_mode: */ ;\
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/* create new stack frame, save only needed gprs */ ;\
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/* r1: KSP, r10: current, r4: EEAR, r31: __pa(KSP) */ ;\
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/* r12: temp, syscall indicator */ ;\
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l.addi r1,r1,-(INT_FRAME_SIZE) ;\
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/* r1 is KSP, r30 is __pa(KSP) */ ;\
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tophys (r30,r1) ;\
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l.sw PT_GPR12(r30),r12 ;\
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/* r4 use for tmp before EA */ ;\
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l.mfspr r12,r0,SPR_EPCR_BASE ;\
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l.sw PT_PC(r30),r12 ;\
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l.mfspr r12,r0,SPR_ESR_BASE ;\
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l.sw PT_SR(r30),r12 ;\
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/* save r30 */ ;\
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EXCEPTION_T_LOAD_GPR30(r12) ;\
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l.sw PT_GPR30(r30),r12 ;\
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/* save r10 as was prior to exception */ ;\
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EXCEPTION_T_LOAD_GPR10(r12) ;\
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l.sw PT_GPR10(r30),r12 ;\
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/* save PT_SP as was prior to exception */ ;\
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EXCEPTION_T_LOAD_SP(r12) ;\
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l.sw PT_SP(r30),r12 ;\
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/* save exception r4, set r4 = EA */ ;\
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l.sw PT_GPR4(r30),r4 ;\
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l.mfspr r4,r0,SPR_EEAR_BASE ;\
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/* r12 == 1 if we come from syscall */ ;\
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CLEAR_GPR(r12) ;\
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/* ----- turn on MMU ----- */ ;\
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/* Carry DSX into exception SR */ ;\
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l.mfspr r30,r0,SPR_SR ;\
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l.andi r30,r30,SPR_SR_DSX ;\
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l.ori r30,r30,(EXCEPTION_SR) ;\
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l.mtspr r0,r30,SPR_ESR_BASE ;\
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/* r30: EA address of handler */ ;\
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LOAD_SYMBOL_2_GPR(r30,handler) ;\
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l.mtspr r0,r30,SPR_EPCR_BASE ;\
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l.rfe
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/*
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* this doesn't work
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*
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*
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* #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
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* #define UNHANDLED_EXCEPTION(handler) \
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* l.ori r3,r0,0x1 ;\
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* l.mtspr r0,r3,SPR_SR ;\
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* l.movhi r3,hi(0xf0000100) ;\
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* l.ori r3,r3,lo(0xf0000100) ;\
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* l.jr r3 ;\
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* l.nop 1
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*
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* #endif
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*/
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/* DSCR: this is the same as EXCEPTION_HANDLE(), we are just
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* a bit more carefull (if we have a PT_SP or current pointer
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* corruption) and set them up from 'current_set'
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*
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*/
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#define UNHANDLED_EXCEPTION(handler) \
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EXCEPTION_T_STORE_GPR30 ;\
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EXCEPTION_T_STORE_GPR10 ;\
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EXCEPTION_T_STORE_SP ;\
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/* temporary store r3, r9 into r1, r10 */ ;\
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l.addi r1,r3,0x0 ;\
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l.addi r10,r9,0x0 ;\
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/* the string referenced by r3 must be low enough */ ;\
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l.jal _emergency_print ;\
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l.ori r3,r0,lo(_string_unhandled_exception) ;\
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l.mfspr r3,r0,SPR_NPC ;\
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l.jal _emergency_print_nr ;\
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l.andi r3,r3,0x1f00 ;\
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/* the string referenced by r3 must be low enough */ ;\
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l.jal _emergency_print ;\
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l.ori r3,r0,lo(_string_epc_prefix) ;\
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l.jal _emergency_print_nr ;\
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l.mfspr r3,r0,SPR_EPCR_BASE ;\
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l.jal _emergency_print ;\
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l.ori r3,r0,lo(_string_nl) ;\
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/* end of printing */ ;\
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l.addi r3,r1,0x0 ;\
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l.addi r9,r10,0x0 ;\
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/* extract current, ksp from current_set */ ;\
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LOAD_SYMBOL_2_GPR(r1,_unhandled_stack_top) ;\
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LOAD_SYMBOL_2_GPR(r10,init_thread_union) ;\
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/* create new stack frame, save only needed gprs */ ;\
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/* r1: KSP, r10: current, r31: __pa(KSP) */ ;\
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/* r12: temp, syscall indicator, r13 temp */ ;\
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l.addi r1,r1,-(INT_FRAME_SIZE) ;\
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/* r1 is KSP, r30 is __pa(KSP) */ ;\
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tophys (r30,r1) ;\
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l.sw PT_GPR12(r30),r12 ;\
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l.mfspr r12,r0,SPR_EPCR_BASE ;\
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l.sw PT_PC(r30),r12 ;\
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l.mfspr r12,r0,SPR_ESR_BASE ;\
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l.sw PT_SR(r30),r12 ;\
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/* save r31 */ ;\
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EXCEPTION_T_LOAD_GPR30(r12) ;\
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l.sw PT_GPR30(r30),r12 ;\
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/* save r10 as was prior to exception */ ;\
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EXCEPTION_T_LOAD_GPR10(r12) ;\
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l.sw PT_GPR10(r30),r12 ;\
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/* save PT_SP as was prior to exception */ ;\
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EXCEPTION_T_LOAD_SP(r12) ;\
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l.sw PT_SP(r30),r12 ;\
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l.sw PT_GPR13(r30),r13 ;\
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/* --> */ ;\
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/* save exception r4, set r4 = EA */ ;\
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l.sw PT_GPR4(r30),r4 ;\
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l.mfspr r4,r0,SPR_EEAR_BASE ;\
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/* r12 == 1 if we come from syscall */ ;\
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CLEAR_GPR(r12) ;\
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/* ----- play a MMU trick ----- */ ;\
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l.ori r30,r0,(EXCEPTION_SR) ;\
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l.mtspr r0,r30,SPR_ESR_BASE ;\
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/* r31: EA address of handler */ ;\
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LOAD_SYMBOL_2_GPR(r30,handler) ;\
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l.mtspr r0,r30,SPR_EPCR_BASE ;\
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l.rfe
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/* =====================================================[ exceptions] === */
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/* ---[ 0x100: RESET exception ]----------------------------------------- */
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.org 0x100
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/* Jump to .init code at _start which lives in the .head section
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* and will be discarded after boot.
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*/
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LOAD_SYMBOL_2_GPR(r15, _start)
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tophys (r13,r15) /* MMU disabled */
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l.jr r13
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l.nop
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/* ---[ 0x200: BUS exception ]------------------------------------------- */
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.org 0x200
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_dispatch_bus_fault:
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EXCEPTION_HANDLE(_bus_fault_handler)
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/* ---[ 0x300: Data Page Fault exception ]------------------------------- */
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.org 0x300
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_dispatch_do_dpage_fault:
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// totaly disable timer interrupt
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// l.mtspr r0,r0,SPR_TTMR
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// DEBUG_TLB_PROBE(0x300)
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// EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x300)
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EXCEPTION_HANDLE(_data_page_fault_handler)
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/* ---[ 0x400: Insn Page Fault exception ]------------------------------- */
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.org 0x400
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_dispatch_do_ipage_fault:
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// totaly disable timer interrupt
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// l.mtspr r0,r0,SPR_TTMR
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// DEBUG_TLB_PROBE(0x400)
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// EXCEPTION_DEBUG_VALUE_ER_ENABLED(0x400)
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EXCEPTION_HANDLE(_insn_page_fault_handler)
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/* ---[ 0x500: Timer exception ]----------------------------------------- */
|
|
.org 0x500
|
|
EXCEPTION_HANDLE(_timer_handler)
|
|
|
|
/* ---[ 0x600: Alignment exception ]-------------------------------------- */
|
|
.org 0x600
|
|
EXCEPTION_HANDLE(_alignment_handler)
|
|
|
|
/* ---[ 0x700: Illegal insn exception ]---------------------------------- */
|
|
.org 0x700
|
|
EXCEPTION_HANDLE(_illegal_instruction_handler)
|
|
|
|
/* ---[ 0x800: External interrupt exception ]---------------------------- */
|
|
.org 0x800
|
|
EXCEPTION_HANDLE(_external_irq_handler)
|
|
|
|
/* ---[ 0x900: DTLB miss exception ]------------------------------------- */
|
|
.org 0x900
|
|
l.j boot_dtlb_miss_handler
|
|
l.nop
|
|
|
|
/* ---[ 0xa00: ITLB miss exception ]------------------------------------- */
|
|
.org 0xa00
|
|
l.j boot_itlb_miss_handler
|
|
l.nop
|
|
|
|
/* ---[ 0xb00: Range exception ]----------------------------------------- */
|
|
.org 0xb00
|
|
UNHANDLED_EXCEPTION(_vector_0xb00)
|
|
|
|
/* ---[ 0xc00: Syscall exception ]--------------------------------------- */
|
|
.org 0xc00
|
|
EXCEPTION_HANDLE(_sys_call_handler)
|
|
|
|
/* ---[ 0xd00: Trap exception ]------------------------------------------ */
|
|
.org 0xd00
|
|
UNHANDLED_EXCEPTION(_vector_0xd00)
|
|
|
|
/* ---[ 0xe00: Trap exception ]------------------------------------------ */
|
|
.org 0xe00
|
|
// UNHANDLED_EXCEPTION(_vector_0xe00)
|
|
EXCEPTION_HANDLE(_trap_handler)
|
|
|
|
/* ---[ 0xf00: Reserved exception ]-------------------------------------- */
|
|
.org 0xf00
|
|
UNHANDLED_EXCEPTION(_vector_0xf00)
|
|
|
|
/* ---[ 0x1000: Reserved exception ]------------------------------------- */
|
|
.org 0x1000
|
|
UNHANDLED_EXCEPTION(_vector_0x1000)
|
|
|
|
/* ---[ 0x1100: Reserved exception ]------------------------------------- */
|
|
.org 0x1100
|
|
UNHANDLED_EXCEPTION(_vector_0x1100)
|
|
|
|
/* ---[ 0x1200: Reserved exception ]------------------------------------- */
|
|
.org 0x1200
|
|
UNHANDLED_EXCEPTION(_vector_0x1200)
|
|
|
|
/* ---[ 0x1300: Reserved exception ]------------------------------------- */
|
|
.org 0x1300
|
|
UNHANDLED_EXCEPTION(_vector_0x1300)
|
|
|
|
/* ---[ 0x1400: Reserved exception ]------------------------------------- */
|
|
.org 0x1400
|
|
UNHANDLED_EXCEPTION(_vector_0x1400)
|
|
|
|
/* ---[ 0x1500: Reserved exception ]------------------------------------- */
|
|
.org 0x1500
|
|
UNHANDLED_EXCEPTION(_vector_0x1500)
|
|
|
|
/* ---[ 0x1600: Reserved exception ]------------------------------------- */
|
|
.org 0x1600
|
|
UNHANDLED_EXCEPTION(_vector_0x1600)
|
|
|
|
/* ---[ 0x1700: Reserved exception ]------------------------------------- */
|
|
.org 0x1700
|
|
UNHANDLED_EXCEPTION(_vector_0x1700)
|
|
|
|
/* ---[ 0x1800: Reserved exception ]------------------------------------- */
|
|
.org 0x1800
|
|
UNHANDLED_EXCEPTION(_vector_0x1800)
|
|
|
|
/* ---[ 0x1900: Reserved exception ]------------------------------------- */
|
|
.org 0x1900
|
|
UNHANDLED_EXCEPTION(_vector_0x1900)
|
|
|
|
/* ---[ 0x1a00: Reserved exception ]------------------------------------- */
|
|
.org 0x1a00
|
|
UNHANDLED_EXCEPTION(_vector_0x1a00)
|
|
|
|
/* ---[ 0x1b00: Reserved exception ]------------------------------------- */
|
|
.org 0x1b00
|
|
UNHANDLED_EXCEPTION(_vector_0x1b00)
|
|
|
|
/* ---[ 0x1c00: Reserved exception ]------------------------------------- */
|
|
.org 0x1c00
|
|
UNHANDLED_EXCEPTION(_vector_0x1c00)
|
|
|
|
/* ---[ 0x1d00: Reserved exception ]------------------------------------- */
|
|
.org 0x1d00
|
|
UNHANDLED_EXCEPTION(_vector_0x1d00)
|
|
|
|
/* ---[ 0x1e00: Reserved exception ]------------------------------------- */
|
|
.org 0x1e00
|
|
UNHANDLED_EXCEPTION(_vector_0x1e00)
|
|
|
|
/* ---[ 0x1f00: Reserved exception ]------------------------------------- */
|
|
.org 0x1f00
|
|
UNHANDLED_EXCEPTION(_vector_0x1f00)
|
|
|
|
.org 0x2000
|
|
/* ===================================================[ kernel start ]=== */
|
|
|
|
/* .text*/
|
|
|
|
/* This early stuff belongs in HEAD, but some of the functions below definitely
|
|
* don't... */
|
|
|
|
__HEAD
|
|
.global _start
|
|
_start:
|
|
/* Init r0 to zero as per spec */
|
|
CLEAR_GPR(r0)
|
|
|
|
/* save kernel parameters */
|
|
l.or r25,r0,r3 /* pointer to fdt */
|
|
|
|
/*
|
|
* ensure a deterministic start
|
|
*/
|
|
|
|
l.ori r3,r0,0x1
|
|
l.mtspr r0,r3,SPR_SR
|
|
|
|
/*
|
|
* Start the TTCR as early as possible, so that the RNG can make use of
|
|
* measurements of boot time from the earliest opportunity. Especially
|
|
* important is that the TTCR does not return zero by the time we reach
|
|
* rand_initialize().
|
|
*/
|
|
l.movhi r3,hi(SPR_TTMR_CR)
|
|
l.mtspr r0,r3,SPR_TTMR
|
|
|
|
CLEAR_GPR(r1)
|
|
CLEAR_GPR(r2)
|
|
CLEAR_GPR(r3)
|
|
CLEAR_GPR(r4)
|
|
CLEAR_GPR(r5)
|
|
CLEAR_GPR(r6)
|
|
CLEAR_GPR(r7)
|
|
CLEAR_GPR(r8)
|
|
CLEAR_GPR(r9)
|
|
CLEAR_GPR(r10)
|
|
CLEAR_GPR(r11)
|
|
CLEAR_GPR(r12)
|
|
CLEAR_GPR(r13)
|
|
CLEAR_GPR(r14)
|
|
CLEAR_GPR(r15)
|
|
CLEAR_GPR(r16)
|
|
CLEAR_GPR(r17)
|
|
CLEAR_GPR(r18)
|
|
CLEAR_GPR(r19)
|
|
CLEAR_GPR(r20)
|
|
CLEAR_GPR(r21)
|
|
CLEAR_GPR(r22)
|
|
CLEAR_GPR(r23)
|
|
CLEAR_GPR(r24)
|
|
CLEAR_GPR(r26)
|
|
CLEAR_GPR(r27)
|
|
CLEAR_GPR(r28)
|
|
CLEAR_GPR(r29)
|
|
CLEAR_GPR(r30)
|
|
CLEAR_GPR(r31)
|
|
|
|
#ifdef CONFIG_SMP
|
|
l.mfspr r26,r0,SPR_COREID
|
|
l.sfeq r26,r0
|
|
l.bnf secondary_wait
|
|
l.nop
|
|
#endif
|
|
/*
|
|
* set up initial ksp and current
|
|
*/
|
|
/* setup kernel stack */
|
|
LOAD_SYMBOL_2_GPR(r1,init_thread_union + THREAD_SIZE)
|
|
LOAD_SYMBOL_2_GPR(r10,init_thread_union) // setup current
|
|
tophys (r31,r10)
|
|
l.sw TI_KSP(r31), r1
|
|
|
|
l.ori r4,r0,0x0
|
|
|
|
|
|
/*
|
|
* .data contains initialized data,
|
|
* .bss contains uninitialized data - clear it up
|
|
*/
|
|
clear_bss:
|
|
LOAD_SYMBOL_2_GPR(r24, __bss_start)
|
|
LOAD_SYMBOL_2_GPR(r26, _end)
|
|
tophys(r28,r24)
|
|
tophys(r30,r26)
|
|
CLEAR_GPR(r24)
|
|
CLEAR_GPR(r26)
|
|
1:
|
|
l.sw (0)(r28),r0
|
|
l.sfltu r28,r30
|
|
l.bf 1b
|
|
l.addi r28,r28,4
|
|
|
|
enable_ic:
|
|
l.jal _ic_enable
|
|
l.nop
|
|
|
|
enable_dc:
|
|
l.jal _dc_enable
|
|
l.nop
|
|
|
|
flush_tlb:
|
|
l.jal _flush_tlb
|
|
l.nop
|
|
|
|
/* The MMU needs to be enabled before or1k_early_setup is called */
|
|
|
|
enable_mmu:
|
|
/*
|
|
* enable dmmu & immu
|
|
* SR[5] = 0, SR[6] = 0, 6th and 7th bit of SR set to 0
|
|
*/
|
|
l.mfspr r30,r0,SPR_SR
|
|
l.movhi r28,hi(SPR_SR_DME | SPR_SR_IME)
|
|
l.ori r28,r28,lo(SPR_SR_DME | SPR_SR_IME)
|
|
l.or r30,r30,r28
|
|
l.mtspr r0,r30,SPR_SR
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
|
|
// reset the simulation counters
|
|
l.nop 5
|
|
|
|
/* check fdt header magic word */
|
|
l.lwz r3,0(r25) /* load magic from fdt into r3 */
|
|
l.movhi r4,hi(OF_DT_HEADER)
|
|
l.ori r4,r4,lo(OF_DT_HEADER)
|
|
l.sfeq r3,r4
|
|
l.bf _fdt_found
|
|
l.nop
|
|
/* magic number mismatch, set fdt pointer to null */
|
|
l.or r25,r0,r0
|
|
_fdt_found:
|
|
/* pass fdt pointer to or1k_early_setup in r3 */
|
|
l.or r3,r0,r25
|
|
LOAD_SYMBOL_2_GPR(r24, or1k_early_setup)
|
|
l.jalr r24
|
|
l.nop
|
|
|
|
clear_regs:
|
|
/*
|
|
* clear all GPRS to increase determinism
|
|
*/
|
|
CLEAR_GPR(r2)
|
|
CLEAR_GPR(r3)
|
|
CLEAR_GPR(r4)
|
|
CLEAR_GPR(r5)
|
|
CLEAR_GPR(r6)
|
|
CLEAR_GPR(r7)
|
|
CLEAR_GPR(r8)
|
|
CLEAR_GPR(r9)
|
|
CLEAR_GPR(r11)
|
|
CLEAR_GPR(r12)
|
|
CLEAR_GPR(r13)
|
|
CLEAR_GPR(r14)
|
|
CLEAR_GPR(r15)
|
|
CLEAR_GPR(r16)
|
|
CLEAR_GPR(r17)
|
|
CLEAR_GPR(r18)
|
|
CLEAR_GPR(r19)
|
|
CLEAR_GPR(r20)
|
|
CLEAR_GPR(r21)
|
|
CLEAR_GPR(r22)
|
|
CLEAR_GPR(r23)
|
|
CLEAR_GPR(r24)
|
|
CLEAR_GPR(r25)
|
|
CLEAR_GPR(r26)
|
|
CLEAR_GPR(r27)
|
|
CLEAR_GPR(r28)
|
|
CLEAR_GPR(r29)
|
|
CLEAR_GPR(r30)
|
|
CLEAR_GPR(r31)
|
|
|
|
jump_start_kernel:
|
|
/*
|
|
* jump to kernel entry (start_kernel)
|
|
*/
|
|
LOAD_SYMBOL_2_GPR(r30, start_kernel)
|
|
l.jr r30
|
|
l.nop
|
|
|
|
_flush_tlb:
|
|
/*
|
|
* I N V A L I D A T E T L B e n t r i e s
|
|
*/
|
|
LOAD_SYMBOL_2_GPR(r5,SPR_DTLBMR_BASE(0))
|
|
LOAD_SYMBOL_2_GPR(r6,SPR_ITLBMR_BASE(0))
|
|
l.addi r7,r0,128 /* Maximum number of sets */
|
|
1:
|
|
l.mtspr r5,r0,0x0
|
|
l.mtspr r6,r0,0x0
|
|
|
|
l.addi r5,r5,1
|
|
l.addi r6,r6,1
|
|
l.sfeq r7,r0
|
|
l.bnf 1b
|
|
l.addi r7,r7,-1
|
|
|
|
l.jr r9
|
|
l.nop
|
|
|
|
#ifdef CONFIG_SMP
|
|
secondary_wait:
|
|
/* Doze the cpu until we are asked to run */
|
|
/* If we dont have power management skip doze */
|
|
l.mfspr r25,r0,SPR_UPR
|
|
l.andi r25,r25,SPR_UPR_PMP
|
|
l.sfeq r25,r0
|
|
l.bf secondary_check_release
|
|
l.nop
|
|
|
|
/* Setup special secondary exception handler */
|
|
LOAD_SYMBOL_2_GPR(r3, _secondary_evbar)
|
|
tophys(r25,r3)
|
|
l.mtspr r0,r25,SPR_EVBAR
|
|
|
|
/* Enable Interrupts */
|
|
l.mfspr r25,r0,SPR_SR
|
|
l.ori r25,r25,SPR_SR_IEE
|
|
l.mtspr r0,r25,SPR_SR
|
|
|
|
/* Unmask interrupts interrupts */
|
|
l.mfspr r25,r0,SPR_PICMR
|
|
l.ori r25,r25,0xffff
|
|
l.mtspr r0,r25,SPR_PICMR
|
|
|
|
/* Doze */
|
|
l.mfspr r25,r0,SPR_PMR
|
|
LOAD_SYMBOL_2_GPR(r3, SPR_PMR_DME)
|
|
l.or r25,r25,r3
|
|
l.mtspr r0,r25,SPR_PMR
|
|
|
|
/* Wakeup - Restore exception handler */
|
|
l.mtspr r0,r0,SPR_EVBAR
|
|
|
|
secondary_check_release:
|
|
/*
|
|
* Check if we actually got the release signal, if not go-back to
|
|
* sleep.
|
|
*/
|
|
l.mfspr r25,r0,SPR_COREID
|
|
LOAD_SYMBOL_2_GPR(r3, secondary_release)
|
|
tophys(r4, r3)
|
|
l.lwz r3,0(r4)
|
|
l.sfeq r25,r3
|
|
l.bnf secondary_wait
|
|
l.nop
|
|
/* fall through to secondary_init */
|
|
|
|
secondary_init:
|
|
/*
|
|
* set up initial ksp and current
|
|
*/
|
|
LOAD_SYMBOL_2_GPR(r10, secondary_thread_info)
|
|
tophys (r30,r10)
|
|
l.lwz r10,0(r30)
|
|
l.addi r1,r10,THREAD_SIZE
|
|
tophys (r30,r10)
|
|
l.sw TI_KSP(r30),r1
|
|
|
|
l.jal _ic_enable
|
|
l.nop
|
|
|
|
l.jal _dc_enable
|
|
l.nop
|
|
|
|
l.jal _flush_tlb
|
|
l.nop
|
|
|
|
/*
|
|
* enable dmmu & immu
|
|
*/
|
|
l.mfspr r30,r0,SPR_SR
|
|
l.movhi r28,hi(SPR_SR_DME | SPR_SR_IME)
|
|
l.ori r28,r28,lo(SPR_SR_DME | SPR_SR_IME)
|
|
l.or r30,r30,r28
|
|
/*
|
|
* This is a bit tricky, we need to switch over from physical addresses
|
|
* to virtual addresses on the fly.
|
|
* To do that, we first set up ESR with the IME and DME bits set.
|
|
* Then EPCR is set to secondary_start and then a l.rfe is issued to
|
|
* "jump" to that.
|
|
*/
|
|
l.mtspr r0,r30,SPR_ESR_BASE
|
|
LOAD_SYMBOL_2_GPR(r30, secondary_start)
|
|
l.mtspr r0,r30,SPR_EPCR_BASE
|
|
l.rfe
|
|
|
|
secondary_start:
|
|
LOAD_SYMBOL_2_GPR(r30, secondary_start_kernel)
|
|
l.jr r30
|
|
l.nop
|
|
|
|
#endif
|
|
|
|
/* ========================================[ cache ]=== */
|
|
|
|
/* alignment here so we don't change memory offsets with
|
|
* memory controller defined
|
|
*/
|
|
.align 0x2000
|
|
|
|
_ic_enable:
|
|
/* Check if IC present and skip enabling otherwise */
|
|
l.mfspr r24,r0,SPR_UPR
|
|
l.andi r26,r24,SPR_UPR_ICP
|
|
l.sfeq r26,r0
|
|
l.bf 9f
|
|
l.nop
|
|
|
|
/* Disable IC */
|
|
l.mfspr r6,r0,SPR_SR
|
|
l.addi r5,r0,-1
|
|
l.xori r5,r5,SPR_SR_ICE
|
|
l.and r5,r6,r5
|
|
l.mtspr r0,r5,SPR_SR
|
|
|
|
/* Establish cache block size
|
|
If BS=0, 16;
|
|
If BS=1, 32;
|
|
r14 contain block size
|
|
*/
|
|
l.mfspr r24,r0,SPR_ICCFGR
|
|
l.andi r26,r24,SPR_ICCFGR_CBS
|
|
l.srli r28,r26,7
|
|
l.ori r30,r0,16
|
|
l.sll r14,r30,r28
|
|
|
|
/* Establish number of cache sets
|
|
r16 contains number of cache sets
|
|
r28 contains log(# of cache sets)
|
|
*/
|
|
l.andi r26,r24,SPR_ICCFGR_NCS
|
|
l.srli r28,r26,3
|
|
l.ori r30,r0,1
|
|
l.sll r16,r30,r28
|
|
|
|
/* Invalidate IC */
|
|
l.addi r6,r0,0
|
|
l.sll r5,r14,r28
|
|
// l.mul r5,r14,r16
|
|
// l.trap 1
|
|
// l.addi r5,r0,IC_SIZE
|
|
1:
|
|
l.mtspr r0,r6,SPR_ICBIR
|
|
l.sfne r6,r5
|
|
l.bf 1b
|
|
l.add r6,r6,r14
|
|
// l.addi r6,r6,IC_LINE
|
|
|
|
/* Enable IC */
|
|
l.mfspr r6,r0,SPR_SR
|
|
l.ori r6,r6,SPR_SR_ICE
|
|
l.mtspr r0,r6,SPR_SR
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
l.nop
|
|
9:
|
|
l.jr r9
|
|
l.nop
|
|
|
|
_dc_enable:
|
|
/* Check if DC present and skip enabling otherwise */
|
|
l.mfspr r24,r0,SPR_UPR
|
|
l.andi r26,r24,SPR_UPR_DCP
|
|
l.sfeq r26,r0
|
|
l.bf 9f
|
|
l.nop
|
|
|
|
/* Disable DC */
|
|
l.mfspr r6,r0,SPR_SR
|
|
l.addi r5,r0,-1
|
|
l.xori r5,r5,SPR_SR_DCE
|
|
l.and r5,r6,r5
|
|
l.mtspr r0,r5,SPR_SR
|
|
|
|
/* Establish cache block size
|
|
If BS=0, 16;
|
|
If BS=1, 32;
|
|
r14 contain block size
|
|
*/
|
|
l.mfspr r24,r0,SPR_DCCFGR
|
|
l.andi r26,r24,SPR_DCCFGR_CBS
|
|
l.srli r28,r26,7
|
|
l.ori r30,r0,16
|
|
l.sll r14,r30,r28
|
|
|
|
/* Establish number of cache sets
|
|
r16 contains number of cache sets
|
|
r28 contains log(# of cache sets)
|
|
*/
|
|
l.andi r26,r24,SPR_DCCFGR_NCS
|
|
l.srli r28,r26,3
|
|
l.ori r30,r0,1
|
|
l.sll r16,r30,r28
|
|
|
|
/* Invalidate DC */
|
|
l.addi r6,r0,0
|
|
l.sll r5,r14,r28
|
|
1:
|
|
l.mtspr r0,r6,SPR_DCBIR
|
|
l.sfne r6,r5
|
|
l.bf 1b
|
|
l.add r6,r6,r14
|
|
|
|
/* Enable DC */
|
|
l.mfspr r6,r0,SPR_SR
|
|
l.ori r6,r6,SPR_SR_DCE
|
|
l.mtspr r0,r6,SPR_SR
|
|
9:
|
|
l.jr r9
|
|
l.nop
|
|
|
|
/* ===============================================[ page table masks ]=== */
|
|
|
|
#define DTLB_UP_CONVERT_MASK 0x3fa
|
|
#define ITLB_UP_CONVERT_MASK 0x3a
|
|
|
|
/* for SMP we'd have (this is a bit subtle, CC must be always set
|
|
* for SMP, but since we have _PAGE_PRESENT bit always defined
|
|
* we can just modify the mask)
|
|
*/
|
|
#define DTLB_SMP_CONVERT_MASK 0x3fb
|
|
#define ITLB_SMP_CONVERT_MASK 0x3b
|
|
|
|
/* ---[ boot dtlb miss handler ]----------------------------------------- */
|
|
|
|
boot_dtlb_miss_handler:
|
|
|
|
/* mask for DTLB_MR register: - (0) sets V (valid) bit,
|
|
* - (31-12) sets bits belonging to VPN (31-12)
|
|
*/
|
|
#define DTLB_MR_MASK 0xfffff001
|
|
|
|
/* mask for DTLB_TR register: - (2) sets CI (cache inhibit) bit,
|
|
* - (4) sets A (access) bit,
|
|
* - (5) sets D (dirty) bit,
|
|
* - (8) sets SRE (superuser read) bit
|
|
* - (9) sets SWE (superuser write) bit
|
|
* - (31-12) sets bits belonging to VPN (31-12)
|
|
*/
|
|
#define DTLB_TR_MASK 0xfffff332
|
|
|
|
/* These are for masking out the VPN/PPN value from the MR/TR registers...
|
|
* it's not the same as the PFN */
|
|
#define VPN_MASK 0xfffff000
|
|
#define PPN_MASK 0xfffff000
|
|
|
|
|
|
EXCEPTION_STORE_GPR6
|
|
|
|
#if 0
|
|
l.mfspr r6,r0,SPR_ESR_BASE //
|
|
l.andi r6,r6,SPR_SR_SM // are we in kernel mode ?
|
|
l.sfeqi r6,0 // r6 == 0x1 --> SM
|
|
l.bf exit_with_no_dtranslation //
|
|
l.nop
|
|
#endif
|
|
|
|
/* this could be optimized by moving storing of
|
|
* non r6 registers here, and jumping r6 restore
|
|
* if not in supervisor mode
|
|
*/
|
|
|
|
EXCEPTION_STORE_GPR2
|
|
EXCEPTION_STORE_GPR3
|
|
EXCEPTION_STORE_GPR4
|
|
EXCEPTION_STORE_GPR5
|
|
|
|
l.mfspr r4,r0,SPR_EEAR_BASE // get the offending EA
|
|
|
|
immediate_translation:
|
|
CLEAR_GPR(r6)
|
|
|
|
l.srli r3,r4,0xd // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb)
|
|
|
|
l.mfspr r6, r0, SPR_DMMUCFGR
|
|
l.andi r6, r6, SPR_DMMUCFGR_NTS
|
|
l.srli r6, r6, SPR_DMMUCFGR_NTS_OFF
|
|
l.ori r5, r0, 0x1
|
|
l.sll r5, r5, r6 // r5 = number DMMU sets
|
|
l.addi r6, r5, -1 // r6 = nsets mask
|
|
l.and r2, r3, r6 // r2 <- r3 % NSETS_MASK
|
|
|
|
l.or r6,r6,r4 // r6 <- r4
|
|
l.ori r6,r6,~(VPN_MASK) // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff
|
|
l.movhi r5,hi(DTLB_MR_MASK) // r5 <- ffff:0000.x000
|
|
l.ori r5,r5,lo(DTLB_MR_MASK) // r5 <- ffff:1111.x001 - apply DTLB_MR_MASK
|
|
l.and r5,r5,r6 // r5 <- VPN :VPN .x001 - we have DTLBMR entry
|
|
l.mtspr r2,r5,SPR_DTLBMR_BASE(0) // set DTLBMR
|
|
|
|
/* set up DTLB with no translation for EA <= 0xbfffffff */
|
|
LOAD_SYMBOL_2_GPR(r6,0xbfffffff)
|
|
l.sfgeu r6,r4 // flag if r6 >= r4 (if 0xbfffffff >= EA)
|
|
l.bf 1f // goto out
|
|
l.and r3,r4,r4 // delay slot :: 24 <- r4 (if flag==1)
|
|
|
|
tophys(r3,r4) // r3 <- PA
|
|
1:
|
|
l.ori r3,r3,~(PPN_MASK) // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff
|
|
l.movhi r5,hi(DTLB_TR_MASK) // r5 <- ffff:0000.x000
|
|
l.ori r5,r5,lo(DTLB_TR_MASK) // r5 <- ffff:1111.x330 - apply DTLB_MR_MASK
|
|
l.and r5,r5,r3 // r5 <- PPN :PPN .x330 - we have DTLBTR entry
|
|
l.mtspr r2,r5,SPR_DTLBTR_BASE(0) // set DTLBTR
|
|
|
|
EXCEPTION_LOAD_GPR6
|
|
EXCEPTION_LOAD_GPR5
|
|
EXCEPTION_LOAD_GPR4
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR2
|
|
|
|
l.rfe // SR <- ESR, PC <- EPC
|
|
|
|
exit_with_no_dtranslation:
|
|
/* EA out of memory or not in supervisor mode */
|
|
EXCEPTION_LOAD_GPR6
|
|
EXCEPTION_LOAD_GPR4
|
|
l.j _dispatch_bus_fault
|
|
|
|
/* ---[ boot itlb miss handler ]----------------------------------------- */
|
|
|
|
boot_itlb_miss_handler:
|
|
|
|
/* mask for ITLB_MR register: - sets V (valid) bit,
|
|
* - sets bits belonging to VPN (15-12)
|
|
*/
|
|
#define ITLB_MR_MASK 0xfffff001
|
|
|
|
/* mask for ITLB_TR register: - sets A (access) bit,
|
|
* - sets SXE (superuser execute) bit
|
|
* - sets bits belonging to VPN (15-12)
|
|
*/
|
|
#define ITLB_TR_MASK 0xfffff050
|
|
|
|
/*
|
|
#define VPN_MASK 0xffffe000
|
|
#define PPN_MASK 0xffffe000
|
|
*/
|
|
|
|
|
|
|
|
EXCEPTION_STORE_GPR2
|
|
EXCEPTION_STORE_GPR3
|
|
EXCEPTION_STORE_GPR4
|
|
EXCEPTION_STORE_GPR5
|
|
EXCEPTION_STORE_GPR6
|
|
|
|
#if 0
|
|
l.mfspr r6,r0,SPR_ESR_BASE //
|
|
l.andi r6,r6,SPR_SR_SM // are we in kernel mode ?
|
|
l.sfeqi r6,0 // r6 == 0x1 --> SM
|
|
l.bf exit_with_no_itranslation
|
|
l.nop
|
|
#endif
|
|
|
|
|
|
l.mfspr r4,r0,SPR_EEAR_BASE // get the offending EA
|
|
|
|
earlyearly:
|
|
CLEAR_GPR(r6)
|
|
|
|
l.srli r3,r4,0xd // r3 <- r4 / 8192 (sets are relative to page size (8Kb) NOT VPN size (4Kb)
|
|
|
|
l.mfspr r6, r0, SPR_IMMUCFGR
|
|
l.andi r6, r6, SPR_IMMUCFGR_NTS
|
|
l.srli r6, r6, SPR_IMMUCFGR_NTS_OFF
|
|
l.ori r5, r0, 0x1
|
|
l.sll r5, r5, r6 // r5 = number IMMU sets from IMMUCFGR
|
|
l.addi r6, r5, -1 // r6 = nsets mask
|
|
l.and r2, r3, r6 // r2 <- r3 % NSETS_MASK
|
|
|
|
l.or r6,r6,r4 // r6 <- r4
|
|
l.ori r6,r6,~(VPN_MASK) // r6 <- VPN :VPN .xfff - clear up lo(r6) to 0x**** *fff
|
|
l.movhi r5,hi(ITLB_MR_MASK) // r5 <- ffff:0000.x000
|
|
l.ori r5,r5,lo(ITLB_MR_MASK) // r5 <- ffff:1111.x001 - apply ITLB_MR_MASK
|
|
l.and r5,r5,r6 // r5 <- VPN :VPN .x001 - we have ITLBMR entry
|
|
l.mtspr r2,r5,SPR_ITLBMR_BASE(0) // set ITLBMR
|
|
|
|
/*
|
|
* set up ITLB with no translation for EA <= 0x0fffffff
|
|
*
|
|
* we need this for head.S mapping (EA = PA). if we move all functions
|
|
* which run with mmu enabled into entry.S, we might be able to eliminate this.
|
|
*
|
|
*/
|
|
LOAD_SYMBOL_2_GPR(r6,0x0fffffff)
|
|
l.sfgeu r6,r4 // flag if r6 >= r4 (if 0xb0ffffff >= EA)
|
|
l.bf 1f // goto out
|
|
l.and r3,r4,r4 // delay slot :: 24 <- r4 (if flag==1)
|
|
|
|
tophys(r3,r4) // r3 <- PA
|
|
1:
|
|
l.ori r3,r3,~(PPN_MASK) // r3 <- PPN :PPN .xfff - clear up lo(r6) to 0x**** *fff
|
|
l.movhi r5,hi(ITLB_TR_MASK) // r5 <- ffff:0000.x000
|
|
l.ori r5,r5,lo(ITLB_TR_MASK) // r5 <- ffff:1111.x050 - apply ITLB_MR_MASK
|
|
l.and r5,r5,r3 // r5 <- PPN :PPN .x050 - we have ITLBTR entry
|
|
l.mtspr r2,r5,SPR_ITLBTR_BASE(0) // set ITLBTR
|
|
|
|
EXCEPTION_LOAD_GPR6
|
|
EXCEPTION_LOAD_GPR5
|
|
EXCEPTION_LOAD_GPR4
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR2
|
|
|
|
l.rfe // SR <- ESR, PC <- EPC
|
|
|
|
exit_with_no_itranslation:
|
|
EXCEPTION_LOAD_GPR4
|
|
EXCEPTION_LOAD_GPR6
|
|
l.j _dispatch_bus_fault
|
|
l.nop
|
|
|
|
/* ====================================================================== */
|
|
/*
|
|
* Stuff below here shouldn't go into .head section... maybe this stuff
|
|
* can be moved to entry.S ???
|
|
*/
|
|
|
|
/* ==============================================[ DTLB miss handler ]=== */
|
|
|
|
/*
|
|
* Comments:
|
|
* Exception handlers are entered with MMU off so the following handler
|
|
* needs to use physical addressing
|
|
*
|
|
*/
|
|
|
|
.text
|
|
ENTRY(dtlb_miss_handler)
|
|
EXCEPTION_STORE_GPR2
|
|
EXCEPTION_STORE_GPR3
|
|
EXCEPTION_STORE_GPR4
|
|
/*
|
|
* get EA of the miss
|
|
*/
|
|
l.mfspr r2,r0,SPR_EEAR_BASE
|
|
/*
|
|
* pmd = (pmd_t *)(current_pgd + pgd_index(daddr));
|
|
*/
|
|
GET_CURRENT_PGD(r3,r4) // r3 is current_pgd, r4 is temp
|
|
l.srli r4,r2,0x18 // >> PAGE_SHIFT + (PAGE_SHIFT - 2)
|
|
l.slli r4,r4,0x2 // to get address << 2
|
|
l.add r3,r4,r3 // r4 is pgd_index(daddr)
|
|
/*
|
|
* if (pmd_none(*pmd))
|
|
* goto pmd_none:
|
|
*/
|
|
tophys (r4,r3)
|
|
l.lwz r3,0x0(r4) // get *pmd value
|
|
l.sfne r3,r0
|
|
l.bnf d_pmd_none
|
|
l.addi r3,r0,0xffffe000 // PAGE_MASK
|
|
|
|
d_pmd_good:
|
|
/*
|
|
* pte = *pte_offset(pmd, daddr);
|
|
*/
|
|
l.lwz r4,0x0(r4) // get **pmd value
|
|
l.and r4,r4,r3 // & PAGE_MASK
|
|
l.srli r2,r2,0xd // >> PAGE_SHIFT, r2 == EEAR
|
|
l.andi r3,r2,0x7ff // (1UL << PAGE_SHIFT - 2) - 1
|
|
l.slli r3,r3,0x2 // to get address << 2
|
|
l.add r3,r3,r4
|
|
l.lwz r3,0x0(r3) // this is pte at last
|
|
/*
|
|
* if (!pte_present(pte))
|
|
*/
|
|
l.andi r4,r3,0x1
|
|
l.sfne r4,r0 // is pte present
|
|
l.bnf d_pte_not_present
|
|
l.addi r4,r0,0xffffe3fa // PAGE_MASK | DTLB_UP_CONVERT_MASK
|
|
/*
|
|
* fill DTLB TR register
|
|
*/
|
|
l.and r4,r3,r4 // apply the mask
|
|
// Determine number of DMMU sets
|
|
l.mfspr r2, r0, SPR_DMMUCFGR
|
|
l.andi r2, r2, SPR_DMMUCFGR_NTS
|
|
l.srli r2, r2, SPR_DMMUCFGR_NTS_OFF
|
|
l.ori r3, r0, 0x1
|
|
l.sll r3, r3, r2 // r3 = number DMMU sets DMMUCFGR
|
|
l.addi r2, r3, -1 // r2 = nsets mask
|
|
l.mfspr r3, r0, SPR_EEAR_BASE
|
|
l.srli r3, r3, 0xd // >> PAGE_SHIFT
|
|
l.and r2, r3, r2 // calc offset: & (NUM_TLB_ENTRIES-1)
|
|
//NUM_TLB_ENTRIES
|
|
l.mtspr r2,r4,SPR_DTLBTR_BASE(0)
|
|
/*
|
|
* fill DTLB MR register
|
|
*/
|
|
l.slli r3, r3, 0xd /* << PAGE_SHIFT => EA & PAGE_MASK */
|
|
l.ori r4,r3,0x1 // set hardware valid bit: DTBL_MR entry
|
|
l.mtspr r2,r4,SPR_DTLBMR_BASE(0)
|
|
|
|
EXCEPTION_LOAD_GPR2
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR4
|
|
l.rfe
|
|
d_pmd_none:
|
|
d_pte_not_present:
|
|
EXCEPTION_LOAD_GPR2
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR4
|
|
EXCEPTION_HANDLE(_dtlb_miss_page_fault_handler)
|
|
|
|
/* ==============================================[ ITLB miss handler ]=== */
|
|
ENTRY(itlb_miss_handler)
|
|
EXCEPTION_STORE_GPR2
|
|
EXCEPTION_STORE_GPR3
|
|
EXCEPTION_STORE_GPR4
|
|
/*
|
|
* get EA of the miss
|
|
*/
|
|
l.mfspr r2,r0,SPR_EEAR_BASE
|
|
|
|
/*
|
|
* pmd = (pmd_t *)(current_pgd + pgd_index(daddr));
|
|
*
|
|
*/
|
|
GET_CURRENT_PGD(r3,r4) // r3 is current_pgd, r5 is temp
|
|
l.srli r4,r2,0x18 // >> PAGE_SHIFT + (PAGE_SHIFT - 2)
|
|
l.slli r4,r4,0x2 // to get address << 2
|
|
l.add r3,r4,r3 // r4 is pgd_index(daddr)
|
|
/*
|
|
* if (pmd_none(*pmd))
|
|
* goto pmd_none:
|
|
*/
|
|
tophys (r4,r3)
|
|
l.lwz r3,0x0(r4) // get *pmd value
|
|
l.sfne r3,r0
|
|
l.bnf i_pmd_none
|
|
l.addi r3,r0,0xffffe000 // PAGE_MASK
|
|
|
|
i_pmd_good:
|
|
/*
|
|
* pte = *pte_offset(pmd, iaddr);
|
|
*
|
|
*/
|
|
l.lwz r4,0x0(r4) // get **pmd value
|
|
l.and r4,r4,r3 // & PAGE_MASK
|
|
l.srli r2,r2,0xd // >> PAGE_SHIFT, r2 == EEAR
|
|
l.andi r3,r2,0x7ff // (1UL << PAGE_SHIFT - 2) - 1
|
|
l.slli r3,r3,0x2 // to get address << 2
|
|
l.add r3,r3,r4
|
|
l.lwz r3,0x0(r3) // this is pte at last
|
|
/*
|
|
* if (!pte_present(pte))
|
|
*
|
|
*/
|
|
l.andi r4,r3,0x1
|
|
l.sfne r4,r0 // is pte present
|
|
l.bnf i_pte_not_present
|
|
l.addi r4,r0,0xffffe03a // PAGE_MASK | ITLB_UP_CONVERT_MASK
|
|
/*
|
|
* fill ITLB TR register
|
|
*/
|
|
l.and r4,r3,r4 // apply the mask
|
|
l.andi r3,r3,0x7c0 // _PAGE_EXEC | _PAGE_SRE | _PAGE_SWE | _PAGE_URE | _PAGE_UWE
|
|
l.sfeq r3,r0
|
|
l.bf itlb_tr_fill //_workaround
|
|
// Determine number of IMMU sets
|
|
l.mfspr r2, r0, SPR_IMMUCFGR
|
|
l.andi r2, r2, SPR_IMMUCFGR_NTS
|
|
l.srli r2, r2, SPR_IMMUCFGR_NTS_OFF
|
|
l.ori r3, r0, 0x1
|
|
l.sll r3, r3, r2 // r3 = number IMMU sets IMMUCFGR
|
|
l.addi r2, r3, -1 // r2 = nsets mask
|
|
l.mfspr r3, r0, SPR_EEAR_BASE
|
|
l.srli r3, r3, 0xd // >> PAGE_SHIFT
|
|
l.and r2, r3, r2 // calc offset: & (NUM_TLB_ENTRIES-1)
|
|
|
|
/*
|
|
* __PHX__ :: fixme
|
|
* we should not just blindly set executable flags,
|
|
* but it does help with ping. the clean way would be to find out
|
|
* (and fix it) why stack doesn't have execution permissions
|
|
*/
|
|
|
|
itlb_tr_fill_workaround:
|
|
l.ori r4,r4,0xc0 // | (SPR_ITLBTR_UXE | ITLBTR_SXE)
|
|
itlb_tr_fill:
|
|
l.mtspr r2,r4,SPR_ITLBTR_BASE(0)
|
|
/*
|
|
* fill DTLB MR register
|
|
*/
|
|
l.slli r3, r3, 0xd /* << PAGE_SHIFT => EA & PAGE_MASK */
|
|
l.ori r4,r3,0x1 // set hardware valid bit: ITBL_MR entry
|
|
l.mtspr r2,r4,SPR_ITLBMR_BASE(0)
|
|
|
|
EXCEPTION_LOAD_GPR2
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR4
|
|
l.rfe
|
|
|
|
i_pmd_none:
|
|
i_pte_not_present:
|
|
EXCEPTION_LOAD_GPR2
|
|
EXCEPTION_LOAD_GPR3
|
|
EXCEPTION_LOAD_GPR4
|
|
EXCEPTION_HANDLE(_itlb_miss_page_fault_handler)
|
|
|
|
/* ==============================================[ boot tlb handlers ]=== */
|
|
|
|
|
|
/* =================================================[ debugging aids ]=== */
|
|
|
|
.align 64
|
|
_immu_trampoline:
|
|
.space 64
|
|
_immu_trampoline_top:
|
|
|
|
#define TRAMP_SLOT_0 (0x0)
|
|
#define TRAMP_SLOT_1 (0x4)
|
|
#define TRAMP_SLOT_2 (0x8)
|
|
#define TRAMP_SLOT_3 (0xc)
|
|
#define TRAMP_SLOT_4 (0x10)
|
|
#define TRAMP_SLOT_5 (0x14)
|
|
#define TRAMP_FRAME_SIZE (0x18)
|
|
|
|
ENTRY(_immu_trampoline_workaround)
|
|
// r2 EEA
|
|
// r6 is physical EEA
|
|
tophys(r6,r2)
|
|
|
|
LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
|
|
tophys (r3,r5) // r3 is trampoline (physical)
|
|
|
|
LOAD_SYMBOL_2_GPR(r4,0x15000000)
|
|
l.sw TRAMP_SLOT_0(r3),r4
|
|
l.sw TRAMP_SLOT_1(r3),r4
|
|
l.sw TRAMP_SLOT_4(r3),r4
|
|
l.sw TRAMP_SLOT_5(r3),r4
|
|
|
|
// EPC = EEA - 0x4
|
|
l.lwz r4,0x0(r6) // load op @ EEA + 0x0 (fc address)
|
|
l.sw TRAMP_SLOT_3(r3),r4 // store it to _immu_trampoline_data
|
|
l.lwz r4,-0x4(r6) // load op @ EEA - 0x4 (f8 address)
|
|
l.sw TRAMP_SLOT_2(r3),r4 // store it to _immu_trampoline_data
|
|
|
|
l.srli r5,r4,26 // check opcode for write access
|
|
l.sfeqi r5,0 // l.j
|
|
l.bf 0f
|
|
l.sfeqi r5,0x11 // l.jr
|
|
l.bf 1f
|
|
l.sfeqi r5,1 // l.jal
|
|
l.bf 2f
|
|
l.sfeqi r5,0x12 // l.jalr
|
|
l.bf 3f
|
|
l.sfeqi r5,3 // l.bnf
|
|
l.bf 4f
|
|
l.sfeqi r5,4 // l.bf
|
|
l.bf 5f
|
|
99:
|
|
l.nop
|
|
l.j 99b // should never happen
|
|
l.nop 1
|
|
|
|
// r2 is EEA
|
|
// r3 is trampoline address (physical)
|
|
// r4 is instruction
|
|
// r6 is physical(EEA)
|
|
//
|
|
// r5
|
|
|
|
2: // l.jal
|
|
|
|
/* 19 20 aa aa l.movhi r9,0xaaaa
|
|
* a9 29 bb bb l.ori r9,0xbbbb
|
|
*
|
|
* where 0xaaaabbbb is EEA + 0x4 shifted right 2
|
|
*/
|
|
|
|
l.addi r6,r2,0x4 // this is 0xaaaabbbb
|
|
|
|
// l.movhi r9,0xaaaa
|
|
l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9
|
|
l.sh (TRAMP_SLOT_0+0x0)(r3),r5
|
|
l.srli r5,r6,16
|
|
l.sh (TRAMP_SLOT_0+0x2)(r3),r5
|
|
|
|
// l.ori r9,0xbbbb
|
|
l.ori r5,r0,0xa929 // 0xa929 == l.ori r9
|
|
l.sh (TRAMP_SLOT_1+0x0)(r3),r5
|
|
l.andi r5,r6,0xffff
|
|
l.sh (TRAMP_SLOT_1+0x2)(r3),r5
|
|
|
|
/* falthrough, need to set up new jump offset */
|
|
|
|
|
|
0: // l.j
|
|
l.slli r6,r4,6 // original offset shifted left 6 - 2
|
|
// l.srli r6,r6,6 // original offset shifted right 2
|
|
|
|
l.slli r4,r2,4 // old jump position: EEA shifted left 4
|
|
// l.srli r4,r4,6 // old jump position: shifted right 2
|
|
|
|
l.addi r5,r3,0xc // new jump position (physical)
|
|
l.slli r5,r5,4 // new jump position: shifted left 4
|
|
|
|
// calculate new jump offset
|
|
// new_off = old_off + (old_jump - new_jump)
|
|
|
|
l.sub r5,r4,r5 // old_jump - new_jump
|
|
l.add r5,r6,r5 // orig_off + (old_jump - new_jump)
|
|
l.srli r5,r5,6 // new offset shifted right 2
|
|
|
|
// r5 is new jump offset
|
|
// l.j has opcode 0x0...
|
|
l.sw TRAMP_SLOT_2(r3),r5 // write it back
|
|
|
|
l.j trampoline_out
|
|
l.nop
|
|
|
|
/* ----------------------------- */
|
|
|
|
3: // l.jalr
|
|
|
|
/* 19 20 aa aa l.movhi r9,0xaaaa
|
|
* a9 29 bb bb l.ori r9,0xbbbb
|
|
*
|
|
* where 0xaaaabbbb is EEA + 0x4 shifted right 2
|
|
*/
|
|
|
|
l.addi r6,r2,0x4 // this is 0xaaaabbbb
|
|
|
|
// l.movhi r9,0xaaaa
|
|
l.ori r5,r0,0x1920 // 0x1920 == l.movhi r9
|
|
l.sh (TRAMP_SLOT_0+0x0)(r3),r5
|
|
l.srli r5,r6,16
|
|
l.sh (TRAMP_SLOT_0+0x2)(r3),r5
|
|
|
|
// l.ori r9,0xbbbb
|
|
l.ori r5,r0,0xa929 // 0xa929 == l.ori r9
|
|
l.sh (TRAMP_SLOT_1+0x0)(r3),r5
|
|
l.andi r5,r6,0xffff
|
|
l.sh (TRAMP_SLOT_1+0x2)(r3),r5
|
|
|
|
l.lhz r5,(TRAMP_SLOT_2+0x0)(r3) // load hi part of jump instruction
|
|
l.andi r5,r5,0x3ff // clear out opcode part
|
|
l.ori r5,r5,0x4400 // opcode changed from l.jalr -> l.jr
|
|
l.sh (TRAMP_SLOT_2+0x0)(r3),r5 // write it back
|
|
|
|
/* falthrough */
|
|
|
|
1: // l.jr
|
|
l.j trampoline_out
|
|
l.nop
|
|
|
|
/* ----------------------------- */
|
|
|
|
4: // l.bnf
|
|
5: // l.bf
|
|
l.slli r6,r4,6 // original offset shifted left 6 - 2
|
|
// l.srli r6,r6,6 // original offset shifted right 2
|
|
|
|
l.slli r4,r2,4 // old jump position: EEA shifted left 4
|
|
// l.srli r4,r4,6 // old jump position: shifted right 2
|
|
|
|
l.addi r5,r3,0xc // new jump position (physical)
|
|
l.slli r5,r5,4 // new jump position: shifted left 4
|
|
|
|
// calculate new jump offset
|
|
// new_off = old_off + (old_jump - new_jump)
|
|
|
|
l.add r6,r6,r4 // (orig_off + old_jump)
|
|
l.sub r6,r6,r5 // (orig_off + old_jump) - new_jump
|
|
l.srli r6,r6,6 // new offset shifted right 2
|
|
|
|
// r6 is new jump offset
|
|
l.lwz r4,(TRAMP_SLOT_2+0x0)(r3) // load jump instruction
|
|
l.srli r4,r4,16
|
|
l.andi r4,r4,0xfc00 // get opcode part
|
|
l.slli r4,r4,16
|
|
l.or r6,r4,r6 // l.b(n)f new offset
|
|
l.sw TRAMP_SLOT_2(r3),r6 // write it back
|
|
|
|
/* we need to add l.j to EEA + 0x8 */
|
|
tophys (r4,r2) // may not be needed (due to shifts down_
|
|
l.addi r4,r4,(0x8 - 0x8) // jump target = r2 + 0x8 (compensate for 0x8)
|
|
// jump position = r5 + 0x8 (0x8 compensated)
|
|
l.sub r4,r4,r5 // jump offset = target - new_position + 0x8
|
|
|
|
l.slli r4,r4,4 // the amount of info in imediate of jump
|
|
l.srli r4,r4,6 // jump instruction with offset
|
|
l.sw TRAMP_SLOT_4(r3),r4 // write it to 4th slot
|
|
|
|
/* fallthrough */
|
|
|
|
trampoline_out:
|
|
// set up new EPC to point to our trampoline code
|
|
LOAD_SYMBOL_2_GPR(r5,_immu_trampoline)
|
|
l.mtspr r0,r5,SPR_EPCR_BASE
|
|
|
|
// immu_trampoline is (4x) CACHE_LINE aligned
|
|
// and only 6 instructions long,
|
|
// so we need to invalidate only 2 lines
|
|
|
|
/* Establish cache block size
|
|
If BS=0, 16;
|
|
If BS=1, 32;
|
|
r14 contain block size
|
|
*/
|
|
l.mfspr r21,r0,SPR_ICCFGR
|
|
l.andi r21,r21,SPR_ICCFGR_CBS
|
|
l.srli r21,r21,7
|
|
l.ori r23,r0,16
|
|
l.sll r14,r23,r21
|
|
|
|
l.mtspr r0,r5,SPR_ICBIR
|
|
l.add r5,r5,r14
|
|
l.mtspr r0,r5,SPR_ICBIR
|
|
|
|
l.jr r9
|
|
l.nop
|
|
|
|
|
|
/*
|
|
* DSCR: prints a string referenced by r3.
|
|
*
|
|
* PRMS: r3 - address of the first character of null
|
|
* terminated string to be printed
|
|
*
|
|
* PREQ: UART at UART_BASE_ADD has to be initialized
|
|
*
|
|
* POST: caller should be aware that r3, r9 are changed
|
|
*/
|
|
ENTRY(_emergency_print)
|
|
EMERGENCY_PRINT_STORE_GPR4
|
|
EMERGENCY_PRINT_STORE_GPR5
|
|
EMERGENCY_PRINT_STORE_GPR6
|
|
EMERGENCY_PRINT_STORE_GPR7
|
|
2:
|
|
l.lbz r7,0(r3)
|
|
l.sfeq r7,r0
|
|
l.bf 9f
|
|
l.nop
|
|
|
|
// putc:
|
|
l.movhi r4,hi(UART_BASE_ADD)
|
|
|
|
l.addi r6,r0,0x20
|
|
1: l.lbz r5,5(r4)
|
|
l.andi r5,r5,0x20
|
|
l.sfeq r5,r6
|
|
l.bnf 1b
|
|
l.nop
|
|
|
|
l.sb 0(r4),r7
|
|
|
|
l.addi r6,r0,0x60
|
|
1: l.lbz r5,5(r4)
|
|
l.andi r5,r5,0x60
|
|
l.sfeq r5,r6
|
|
l.bnf 1b
|
|
l.nop
|
|
|
|
/* next character */
|
|
l.j 2b
|
|
l.addi r3,r3,0x1
|
|
|
|
9:
|
|
EMERGENCY_PRINT_LOAD_GPR7
|
|
EMERGENCY_PRINT_LOAD_GPR6
|
|
EMERGENCY_PRINT_LOAD_GPR5
|
|
EMERGENCY_PRINT_LOAD_GPR4
|
|
l.jr r9
|
|
l.nop
|
|
|
|
ENTRY(_emergency_print_nr)
|
|
EMERGENCY_PRINT_STORE_GPR4
|
|
EMERGENCY_PRINT_STORE_GPR5
|
|
EMERGENCY_PRINT_STORE_GPR6
|
|
EMERGENCY_PRINT_STORE_GPR7
|
|
EMERGENCY_PRINT_STORE_GPR8
|
|
|
|
l.addi r8,r0,32 // shift register
|
|
|
|
1: /* remove leading zeros */
|
|
l.addi r8,r8,-0x4
|
|
l.srl r7,r3,r8
|
|
l.andi r7,r7,0xf
|
|
|
|
/* don't skip the last zero if number == 0x0 */
|
|
l.sfeqi r8,0x4
|
|
l.bf 2f
|
|
l.nop
|
|
|
|
l.sfeq r7,r0
|
|
l.bf 1b
|
|
l.nop
|
|
|
|
2:
|
|
l.srl r7,r3,r8
|
|
|
|
l.andi r7,r7,0xf
|
|
l.sflts r8,r0
|
|
l.bf 9f
|
|
|
|
l.sfgtui r7,0x9
|
|
l.bnf 8f
|
|
l.nop
|
|
l.addi r7,r7,0x27
|
|
|
|
8:
|
|
l.addi r7,r7,0x30
|
|
// putc:
|
|
l.movhi r4,hi(UART_BASE_ADD)
|
|
|
|
l.addi r6,r0,0x20
|
|
1: l.lbz r5,5(r4)
|
|
l.andi r5,r5,0x20
|
|
l.sfeq r5,r6
|
|
l.bnf 1b
|
|
l.nop
|
|
|
|
l.sb 0(r4),r7
|
|
|
|
l.addi r6,r0,0x60
|
|
1: l.lbz r5,5(r4)
|
|
l.andi r5,r5,0x60
|
|
l.sfeq r5,r6
|
|
l.bnf 1b
|
|
l.nop
|
|
|
|
/* next character */
|
|
l.j 2b
|
|
l.addi r8,r8,-0x4
|
|
|
|
9:
|
|
EMERGENCY_PRINT_LOAD_GPR8
|
|
EMERGENCY_PRINT_LOAD_GPR7
|
|
EMERGENCY_PRINT_LOAD_GPR6
|
|
EMERGENCY_PRINT_LOAD_GPR5
|
|
EMERGENCY_PRINT_LOAD_GPR4
|
|
l.jr r9
|
|
l.nop
|
|
|
|
|
|
/*
|
|
* This should be used for debugging only.
|
|
* It messes up the Linux early serial output
|
|
* somehow, so use it sparingly and essentially
|
|
* only if you need to debug something that goes wrong
|
|
* before Linux gets the early serial going.
|
|
*
|
|
* Furthermore, you'll have to make sure you set the
|
|
* UART_DEVISOR correctly according to the system
|
|
* clock rate.
|
|
*
|
|
*
|
|
*/
|
|
|
|
|
|
|
|
#define SYS_CLK 20000000
|
|
//#define SYS_CLK 1843200
|
|
#define OR32_CONSOLE_BAUD 115200
|
|
#define UART_DIVISOR SYS_CLK/(16*OR32_CONSOLE_BAUD)
|
|
|
|
ENTRY(_early_uart_init)
|
|
l.movhi r3,hi(UART_BASE_ADD)
|
|
|
|
l.addi r4,r0,0x7
|
|
l.sb 0x2(r3),r4
|
|
|
|
l.addi r4,r0,0x0
|
|
l.sb 0x1(r3),r4
|
|
|
|
l.addi r4,r0,0x3
|
|
l.sb 0x3(r3),r4
|
|
|
|
l.lbz r5,3(r3)
|
|
l.ori r4,r5,0x80
|
|
l.sb 0x3(r3),r4
|
|
l.addi r4,r0,((UART_DIVISOR>>8) & 0x000000ff)
|
|
l.sb UART_DLM(r3),r4
|
|
l.addi r4,r0,((UART_DIVISOR) & 0x000000ff)
|
|
l.sb UART_DLL(r3),r4
|
|
l.sb 0x3(r3),r5
|
|
|
|
l.jr r9
|
|
l.nop
|
|
|
|
.align 0x1000
|
|
.global _secondary_evbar
|
|
_secondary_evbar:
|
|
|
|
.space 0x800
|
|
/* Just disable interrupts and Return */
|
|
l.ori r3,r0,SPR_SR_SM
|
|
l.mtspr r0,r3,SPR_ESR_BASE
|
|
l.rfe
|
|
|
|
|
|
.section .rodata
|
|
_string_unhandled_exception:
|
|
.string "\n\rRunarunaround: Unhandled exception 0x\0"
|
|
|
|
_string_epc_prefix:
|
|
.string ": EPC=0x\0"
|
|
|
|
_string_nl:
|
|
.string "\n\r\0"
|
|
|
|
|
|
/* ========================================[ page aligned structures ]=== */
|
|
|
|
/*
|
|
* .data section should be page aligned
|
|
* (look into arch/openrisc/kernel/vmlinux.lds.S)
|
|
*/
|
|
.section .data,"aw"
|
|
.align 8192
|
|
.global empty_zero_page
|
|
empty_zero_page:
|
|
.space 8192
|
|
|
|
.global swapper_pg_dir
|
|
swapper_pg_dir:
|
|
.space 8192
|
|
|
|
.global _unhandled_stack
|
|
_unhandled_stack:
|
|
.space 8192
|
|
_unhandled_stack_top:
|
|
|
|
/* ============================================================[ EOF ]=== */
|