Commit 42fde305 authored by Simon Glass's avatar Simon Glass

x86: Add support for passing tables into U-Boot

The EFI stub provides information to U-Boot in a table. This includes the
memory map which is needed to decide where to relocate U-Boot. Collect this
information in the early init code and store it in global_data.

Fix up the BIST code at the same time since we don't have it when booting
from EFI and can assume it is 0.
Signed-off-by: default avatarSimon Glass <>
Reviewed-by: default avatarBin Meng <>
parent 96a8d409
......@@ -42,6 +42,13 @@ _x86boot_start:
/* Tell 32-bit code it is being entered from an in-RAM copy */
movl $GD_FLG_WARM_BOOT, %ebx
* Zero the BIST (Built-In Self Test) value since we don't have it.
* It must be 0 or the previous loader would have reported an error.
movl $0, %ebp
jmp 1f
/* Add a way for tools to discover the _start entry point */
......@@ -53,9 +60,13 @@ _start:
* Set %ebx to GD_FLG_COLD_BOOT to indicate this.
movl $GD_FLG_COLD_BOOT, %ebx
/* Save BIST */
movl %eax, %ebp
/* Save table pointer */
movl %ecx, %esi
/* Load the segement registers to match the GDT loaded in start16.S */
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
......@@ -133,7 +144,13 @@ car_init_ret:
movl %esi, (%edx)
/* Store table pointer */
movl %esp, %edx
addl $GD_TABLE, %edx
movl %esi, (%edx)
/* Setup first parameter to setup_gdt, pointer to global_data */
movl %esp, %eax
......@@ -69,6 +69,7 @@ struct arch_global_data {
char *mrc_output;
unsigned int mrc_output_len;
void *gdt; /* Global descriptor table */
ulong table; /* Table pointer from previous loader */
......@@ -21,5 +21,6 @@ int main(void)
DEFINE(GD_HOB_LIST, offsetof(gd_t, arch.hob_list));
DEFINE(GD_TABLE, offsetof(gd_t, arch.table));
return 0;
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