x86: Allow a UART to be set up before the FSP is ready

Since the FSP is a black box it helps to have some sort of debugging
available to check its inputs. If the debug UART is in use, set it up
after CAR is available.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/include/asm/u-boot-x86.h

@@ -45,6 +45,9 @@ ulong board_get_usable_ram_top(ulong total_size);
 void dram_init_banksize(void);
 int default_print_cpuinfo(void);
 
+/* Set up a UART which can be used with printch(), printhex8(), etc. */
+int setup_early_uart(void);
+
 void setup_pcat_compatibility(void);
 
 void isa_unmap_rom(u32 addr);

arch/x86/lib/fsp/fsp_support.c

@@ -124,6 +124,10 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
 	struct fsp_init_params *params_ptr;
 	struct upd_region *fsp_upd;
 
+#ifdef CONFIG_DEBUG_UART
+	setup_early_uart();
+#endif
+
 	fsp_hdr = find_fsp_header();
 	if (fsp_hdr == NULL) {
 		/* No valid FSP info header was found */