mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-15 17:28:15 +00:00
48aa6c2614
Add some comments in start.S for the fact that with FSP U-Boot actually enters the code twice. Also change to use fsp_init() and fsp_continue for accuracy. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
226 lines
5.2 KiB
ArmAsm
226 lines
5.2 KiB
ArmAsm
/*
|
|
* U-Boot - x86 Startup Code
|
|
*
|
|
* (C) Copyright 2008-2011
|
|
* Graeme Russ, <graeme.russ@gmail.com>
|
|
*
|
|
* (C) Copyright 2002
|
|
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <config.h>
|
|
#include <asm/global_data.h>
|
|
#include <asm/post.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/processor-flags.h>
|
|
#include <generated/generic-asm-offsets.h>
|
|
#include <generated/asm-offsets.h>
|
|
|
|
.section .text
|
|
.code32
|
|
.globl _start
|
|
.type _start, @function
|
|
.globl _x86boot_start
|
|
_x86boot_start:
|
|
/*
|
|
* This is the fail-safe 32-bit bootstrap entry point.
|
|
*
|
|
* This code is used when booting from another boot loader like
|
|
* coreboot or EFI. So we repeat some of the same init found in
|
|
* start16.
|
|
*/
|
|
cli
|
|
cld
|
|
|
|
/* Turn off cache (this might require a 486-class CPU) */
|
|
movl %cr0, %eax
|
|
orl $(X86_CR0_NW | X86_CR0_CD), %eax
|
|
movl %eax, %cr0
|
|
wbinvd
|
|
|
|
/* 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 */
|
|
.align 4
|
|
.long 0x12345678
|
|
_start:
|
|
/*
|
|
* This is the 32-bit cold-reset entry point, coming from start16.
|
|
* Set %ebx to GD_FLG_COLD_BOOT to indicate this.
|
|
*/
|
|
movl $GD_FLG_COLD_BOOT, %ebx
|
|
|
|
/* Save BIST */
|
|
movl %eax, %ebp
|
|
1:
|
|
|
|
/* 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
|
|
movw %ax, %fs
|
|
movw %ax, %ds
|
|
movw %ax, %gs
|
|
movw %ax, %es
|
|
movw %ax, %ss
|
|
|
|
/* Clear the interrupt vectors */
|
|
lidt blank_idt_ptr
|
|
|
|
/*
|
|
* Critical early platform init - generally not used, we prefer init
|
|
* to happen later when we have a console, in case something goes
|
|
* wrong.
|
|
*/
|
|
jmp early_board_init
|
|
.globl early_board_init_ret
|
|
early_board_init_ret:
|
|
post_code(POST_START)
|
|
|
|
/* Initialise Cache-As-RAM */
|
|
jmp car_init
|
|
.globl car_init_ret
|
|
car_init_ret:
|
|
#ifndef CONFIG_HAVE_FSP
|
|
/*
|
|
* We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
|
|
* or fully initialised SDRAM - we really don't care which)
|
|
* starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
|
|
* and early malloc() area. The MRC requires some space at the top.
|
|
*
|
|
* Stack grows down from top of CAR. We have:
|
|
*
|
|
* top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE
|
|
* MRC area
|
|
* global_data with x86 global descriptor table
|
|
* early malloc area
|
|
* stack
|
|
* bottom-> CONFIG_SYS_CAR_ADDR
|
|
*/
|
|
movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %esp
|
|
#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
|
|
subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
|
|
#endif
|
|
#else
|
|
/*
|
|
* U-Boot enters here twice. For the first time it comes from
|
|
* car_init_done() with esp points to a temporary stack and esi
|
|
* set to zero. For the second time it comes from fsp_init_done()
|
|
* with esi holding the HOB list address returned by the FSP.
|
|
*/
|
|
#endif
|
|
/* Set up global data */
|
|
mov %esp, %eax
|
|
call board_init_f_mem
|
|
mov %eax, %esp
|
|
|
|
/*
|
|
* Debug UART is available here although it may not be plumbed out
|
|
* to pins depending on the board. To use it:
|
|
*
|
|
* call debug_uart_init
|
|
* mov $'a', %eax
|
|
* call printch
|
|
*/
|
|
|
|
/* Get address of global_data */
|
|
mov %fs:0, %edx
|
|
#ifdef CONFIG_HAVE_FSP
|
|
/* Store the HOB list if we have one */
|
|
test %esi, %esi
|
|
jz skip_hob
|
|
movl %esi, GD_HOB_LIST(%edx)
|
|
|
|
/*
|
|
* After fsp_init() returns, the stack has already been switched to a
|
|
* place within system memory as defined by CONFIG_FSP_TEMP_RAM_ADDR.
|
|
* Enlarge the size of malloc() pool before relocation since we have
|
|
* plenty of memory now.
|
|
*/
|
|
subl $CONFIG_FSP_SYS_MALLOC_F_LEN, %esp
|
|
movl %esp, GD_MALLOC_BASE(%edx)
|
|
skip_hob:
|
|
#else
|
|
/* Store table pointer */
|
|
movl %esi, GD_TABLE(%edx)
|
|
#endif
|
|
/* Store BIST */
|
|
movl %ebp, GD_BIST(%edx)
|
|
|
|
/* Set parameter to board_init_f() to boot flags */
|
|
post_code(POST_START_DONE)
|
|
xorl %eax, %eax
|
|
|
|
/* Enter, U-Boot! */
|
|
call board_init_f
|
|
|
|
/* indicate (lack of) progress */
|
|
movw $0x85, %ax
|
|
jmp die
|
|
|
|
.globl board_init_f_r_trampoline
|
|
.type board_init_f_r_trampoline, @function
|
|
board_init_f_r_trampoline:
|
|
/*
|
|
* 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 */
|
|
movl %eax, %esp
|
|
|
|
/* See if we need to disable CAR */
|
|
.weak car_uninit
|
|
movl $car_uninit, %eax
|
|
cmpl $0, %eax
|
|
jz 1f
|
|
|
|
call car_uninit
|
|
1:
|
|
/* Re-enter U-Boot by calling board_init_f_r() */
|
|
call board_init_f_r
|
|
|
|
die:
|
|
hlt
|
|
jmp die
|
|
hlt
|
|
|
|
blank_idt_ptr:
|
|
.word 0 /* limit */
|
|
.long 0 /* base */
|
|
|
|
.p2align 2 /* force 4-byte alignment */
|
|
|
|
/* Add a multiboot header so U-Boot can be loaded by GRUB2 */
|
|
multiboot_header:
|
|
/* magic */
|
|
.long 0x1badb002
|
|
/* flags */
|
|
.long (1 << 16)
|
|
/* checksum */
|
|
.long -0x1BADB002 - (1 << 16)
|
|
/* header addr */
|
|
.long multiboot_header - _x86boot_start + CONFIG_SYS_TEXT_BASE
|
|
/* load addr */
|
|
.long CONFIG_SYS_TEXT_BASE
|
|
/* load end addr */
|
|
.long 0
|
|
/* bss end addr */
|
|
.long 0
|
|
/* entry addr */
|
|
.long CONFIG_SYS_TEXT_BASE
|