u-boot/arch/x86/cpu/start.S
Bin Meng bceb9f0fc8 x86: Support Intel FSP initialization path in start.S
Per Intel FSP architecture specification, FSP provides 3 routines
for bootloader to call. The first one is the TempRamInit (aka
Cache-As-Ram initialization) and the second one is the FspInit
which does the memory bring up (like MRC for other x86 targets)
and chipset initialization. Those two routines have to be called
before U-Boot jumping to board_init_f in start.S.

The FspInit() will return several memory blocks called Hand Off
Blocks (HOBs) whose format is described in Platform Initialization
(PI) specification (part of the UEFI specication) to the bootloader.
Save this HOB address to the U-Boot global data for later use.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2014-12-13 22:32:05 -07:00

238 lines
5.4 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 <version.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. The
* following code is not executed from a cold-reset (actually, a
* lot of it is, but from real-mode after cold reset. It is
* repeated here to put the board into a state as close to cold
* reset as necessary)
*/
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 */
movw $GD_FLG_WARM_BOOT, %bx
jmp 1f
_start:
/*
* This is the 32-bit cold-reset entry point. Initialize %bx to 0
* in case we're preceeded by some sort of boot stub.
*/
movw $GD_FLG_COLD_BOOT, %bx
1:
/* Save BIST */
movl %eax, %ebp
/* Load the segement registes 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
/* Early platform init (setup gpio, etc ) */
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
* 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
/*
* When we get here after car_init, esp points to a temporary stack
* and esi holds the HOB list address returned by the FSP.
*/
#endif
/* Reserve space on stack for global data */
subl $GENERATED_GBL_DATA_SIZE, %esp
/* Align global data to 16-byte boundary */
andl $0xfffffff0, %esp
post_code(POST_START_STACK)
/* Zero the global data since it won't happen later */
xorl %eax, %eax
movl $GENERATED_GBL_DATA_SIZE, %ecx
movl %esp, %edi
rep stosb
#ifdef CONFIG_HAVE_FSP
/* Store HOB list */
movl %esp, %edx
addl $GD_HOB_LIST, %edx
movl %esi, (%edx)
#endif
/* Setup first parameter to setup_gdt, pointer to global_data */
movl %esp, %eax
/* Reserve space for global descriptor table */
subl $X86_GDT_SIZE, %esp
/* Align temporary global descriptor table to 16-byte boundary */
andl $0xfffffff0, %esp
movl %esp, %ecx
#if defined(CONFIG_SYS_MALLOC_F_LEN)
subl $CONFIG_SYS_MALLOC_F_LEN, %esp
movl %eax, %edx
addl $GD_MALLOC_BASE, %edx
movl %esp, (%edx)
#endif
/* Store BIST */
movl %eax, %edx
addl $GD_BIST, %edx
movl %ebp, (%edx)
/* Set second parameter to setup_gdt */
movl %ecx, %edx
/* Setup global descriptor table so gd->xyz works */
call setup_gdt
/* 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
/* Reserve space on stack for global data */
subl $GENERATED_GBL_DATA_SIZE, %esp
/* Align global data to 16-byte boundary */
andl $0xfffffff0, %esp
/* Setup first parameter to memcpy (and setup_gdt) */
movl %esp, %eax
/* Setup second parameter to memcpy */
fs movl 0, %edx
/* Set third parameter to memcpy */
movl $GENERATED_GBL_DATA_SIZE, %ecx
/* Copy global data from CAR to SDRAM stack */
call memcpy
/* Reserve space for global descriptor table */
subl $X86_GDT_SIZE, %esp
/* Align global descriptor table to 16-byte boundary */
andl $0xfffffff0, %esp
/* Set second parameter to setup_gdt */
movl %esp, %edx
/* Setup global descriptor table so gd->xyz works */
call setup_gdt
/* 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 */
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