x86: Implement fully relocatable image
u-boot.bin can be loaded at any 4-byte aligned memory location and directly
'jumped' to using the 'go' command using the load address as the start
address. Doing so performs a 'warm boot' which skips memory initialisation
and other low-level initialisations, relocates U-Boot to upper memory and
starts U-Boot in RAM as per normal 'cold boot'
diff --git a/arch/i386/lib/board.c b/arch/i386/lib/board.c
index 9c2f77f..1129918 100644
--- a/arch/i386/lib/board.c
+++ b/arch/i386/lib/board.c
@@ -190,18 +190,21 @@
dest_addr = (void *)gdp - (bss_end - text_start);
rel_offset = text_start - dest_addr;
- /* First stage CPU initialization */
- if (cpu_init_f() != 0)
- hang();
+ /* Perform low-level initialization only when cold booted */
+ if (((gd_t *)gdp)->flags & GD_FLG_COLD_BOOT) {
+ /* First stage CPU initialization */
+ if (cpu_init_f() != 0)
+ hang();
- /* First stage Board initialization */
- if (board_early_init_f() != 0)
- hang();
+ /* First stage Board initialization */
+ if (board_early_init_f() != 0)
+ hang();
+ }
/* Copy U-Boot into RAM */
dst_addr = (ulong *)dest_addr;
- src_addr = (ulong *)text_start;
- end_addr = (ulong *)data_end;
+ src_addr = (ulong *)(text_start + ((gd_t *)gdp)->load_off);
+ end_addr = (ulong *)(data_end + ((gd_t *)gdp)->load_off);
while (src_addr < end_addr)
*dst_addr++ = *src_addr++;
@@ -214,8 +217,8 @@
*dst_addr++ = 0x00000000;
/* Perform relocation adjustments */
- re_src = (Elf32_Rel *)rel_dyn_start;
- re_end = (Elf32_Rel *)rel_dyn_end;
+ re_src = (Elf32_Rel *)(rel_dyn_start + ((gd_t *)gdp)->load_off);
+ re_end = (Elf32_Rel *)(rel_dyn_end + ((gd_t *)gdp)->load_off);
do {
if (re_src->r_offset >= TEXT_BASE)