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x86: Improve the trampoline in 64-bit mode

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At present this leaves the stack at the pre-relocation value. This is not
ideal since we want to have U-Boot running entirely from the top of
memory.

In addition, the new global_data pointer is not actually used, since
the global_data pointer itself is relocated, then the pre-relocation value
is changed, so the effective value (after relocation) does not update.

Adjust the implementation to follow the 32-bit code more closely, with a
trampoline function which is passed the new stack and global_data pointer.
This ensures that the correct values come through even when relocating.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2023-07-15 21:38:52 -06:00 • committed by Bin Meng
parent 3710802ebf
commit 8f015d3781
3 changed files with 37 additions and 5 deletions
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19
arch/x86/cpu/start64.S
View file

@ -26,3 +26,22 @@ _start:
/* Should not return here */
jmp .
.globl board_init_f_r_trampoline64
.type board_init_f_r_trampoline64, @function
board_init_f_r_trampoline64:
/*
* SDRAM has been initialised, U-Boot code has been copied into
* RAM, BSS has been cleared and relocation adjustments have been
* made. It is now time to jump into the in-RAM copy of U-Boot
*
* %eax = Address of top of new stack
*/
/* Stack grows down from top of SDRAM */
movq %rsi, %rsp
/* New gd is in rdi */
/* Re-enter U-Boot by calling board_init_f_r() */
call board_init_f_r

11
arch/x86/include/asm/u-boot-x86.h
View file

@ -117,6 +117,17 @@ void __noreturn board_init_f_r_trampoline(ulong sp);
*/
void __noreturn board_init_f_r(void);
/*
* board_init_f_r_trampoline64() - jump to relocated address with new stack
*
* This is the 64-bit version
*
* @new_gd: New global_data pointer to use
* @sp: New stack pointer to pass on to board_init_r()
*/
void __noreturn board_init_f_r_trampoline64(struct global_data *new_gd,
ulong sp);
int arch_misc_init(void);
/* Read the time stamp counter */

12
common/board_f.c
View file

@ -729,8 +729,7 @@ static int fix_fdt(void)
#endif
/* ARM calls relocate_code from its crt0.S */
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX) && \
!CONFIG_IS_ENABLED(X86_64)
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX)
static int jump_to_copy(void)
{
@ -752,7 +751,11 @@ static int jump_to_copy(void)
* (CPU cache)
*/
arch_setup_gd(gd->new_gd);
board_init_f_r_trampoline(gd->start_addr_sp);
# if CONFIG_IS_ENABLED(X86_64)
board_init_f_r_trampoline64(gd->new_gd, gd->start_addr_sp);
# else
board_init_f_r_trampoline(gd->start_addr_sp);
# endif
#else
relocate_code(gd->start_addr_sp, gd->new_gd, gd->relocaddr);
#endif
@ -967,8 +970,7 @@ static const init_fnc_t init_sequence_f[] = {
* watchdog device is not serviced is as small as possible.
*/
cyclic_unregister_all,
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX) && \
!CONFIG_IS_ENABLED(X86_64)
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX)
jump_to_copy,
#endif
NULL,