ubuntu-linux-kernel/arch/mn10300/boot/compressed/head.S

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2024-04-01 15:06:58 +00:00
/* Boot entry point for a compressed MN10300 kernel
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
.section .text
#define DEBUG
#include <linux/linkage.h>
#include <asm/cpu-regs.h>
#include <asm/cache.h>
#ifdef CONFIG_SMP
#include <proc/smp-regs.h>
#endif
.globl startup_32
startup_32:
#ifdef CONFIG_SMP
#
# Secondary CPUs jump directly to the kernel entry point
#
# Must save primary CPU's D0-D2 registers as they hold boot parameters
#
mov (CPUID), d3
and CPUID_MASK,d3
beq startup_primary
mov CONFIG_KERNEL_TEXT_ADDRESS,a0
jmp (a0)
startup_primary:
#endif /* CONFIG_SMP */
# first save parameters from bootloader
mov param_save_area,a0
mov d0,(a0)
mov d1,(4,a0)
mov d2,(8,a0)
mov sp,a3
mov decomp_stack+0x2000-4,a0
mov a0,sp
# invalidate and enable both of the caches
mov CHCTR,a0
clr d0
movhu d0,(a0) # turn off first
mov CHCTR_ICINV|CHCTR_DCINV,d0
movhu d0,(a0)
setlb
mov (a0),d0
btst CHCTR_ICBUSY|CHCTR_DCBUSY,d0 # wait till not busy
lne
#ifdef CONFIG_MN10300_CACHE_ENABLED
#ifdef CONFIG_MN10300_CACHE_WBACK
mov CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRBACK,d0
#else
mov CHCTR_ICEN|CHCTR_DCEN|CHCTR_DCWTMD_WRTHROUGH,d0
#endif /* WBACK */
movhu d0,(a0) # enable
#endif /* !ENABLED */
# clear the BSS area
mov __bss_start,a0
mov _end,a1
clr d0
bssclear:
cmp a1,a0
bge bssclear_end
movbu d0,(a0)
inc a0
bra bssclear
bssclear_end:
# decompress the kernel
call decompress_kernel[],0
#ifdef CONFIG_MN10300_CACHE_WBACK
call mn10300_dcache_flush_inv[],0
#endif
# disable caches again
mov CHCTR,a0
clr d0
movhu d0,(a0)
setlb
mov (a0),d0
btst CHCTR_ICBUSY|CHCTR_DCBUSY,d0 # wait till not busy
lne
mov param_save_area,a0
mov (a0),d0
mov (4,a0),d1
mov (8,a0),d2
# jump to the kernel proper entry point
mov a3,sp
mov CONFIG_KERNEL_TEXT_ADDRESS,a0
jmp (a0)
###############################################################################
#
# Cache flush routines
#
###############################################################################
#ifdef CONFIG_MN10300_CACHE_WBACK
mn10300_dcache_flush_inv:
movhu (CHCTR),d0
btst CHCTR_DCEN,d0
beq mn10300_dcache_flush_inv_end
mov L1_CACHE_NENTRIES,d1
clr a1
mn10300_dcache_flush_inv_loop:
mov (DCACHE_PURGE_WAY0(0),a1),d0 # unconditional purge
mov (DCACHE_PURGE_WAY1(0),a1),d0 # unconditional purge
mov (DCACHE_PURGE_WAY2(0),a1),d0 # unconditional purge
mov (DCACHE_PURGE_WAY3(0),a1),d0 # unconditional purge
add L1_CACHE_BYTES,a1
add -1,d1
bne mn10300_dcache_flush_inv_loop
mn10300_dcache_flush_inv_end:
ret [],0
#endif /* CONFIG_MN10300_CACHE_WBACK */
###############################################################################
#
# Data areas
#
###############################################################################
.data
.align 4
param_save_area:
.rept 3
.word 0
.endr
.section .bss
.align 4
decomp_stack:
.space 0x2000