u-boot/arch/x86/cpu/wakeup.S
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

77 lines
1.6 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
*
* From coreboot src/arch/x86/wakeup.S
*/
#include <asm/acpi_s3.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#define RELOCATED(x) ((x) - __wakeup + WAKEUP_BASE)
#define CODE_SEG (X86_GDT_ENTRY_16BIT_CS * X86_GDT_ENTRY_SIZE)
#define DATA_SEG (X86_GDT_ENTRY_16BIT_DS * X86_GDT_ENTRY_SIZE)
.code32
.globl __wakeup
__wakeup:
/* First prepare the jmp to the resume vector */
mov 0x4(%esp), %eax /* vector */
/* last 4 bits of linear addr are taken as offset */
andw $0x0f, %ax
movw %ax, (__wakeup_offset)
mov 0x4(%esp), %eax
/* the rest is taken as segment */
shr $4, %eax
movw %ax, (__wakeup_segment)
/* Activate the right segment descriptor real mode */
ljmp $CODE_SEG, $RELOCATED(1f)
1:
/* 16 bit code from here on... */
.code16
/*
* Load the segment registers w/ properly configured segment
* descriptors. They will retain these configurations (limits,
* writability, etc.) once protected mode is turned off.
*/
mov $DATA_SEG, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
mov %ax, %ss
/* Turn off protection */
movl %cr0, %eax
andl $~X86_CR0_PE, %eax
movl %eax, %cr0
/* Now really going into real mode */
ljmp $0, $RELOCATED(1f)
1:
movw $0x0, %ax
movw %ax, %ds
movw %ax, %es
movw %ax, %ss
movw %ax, %fs
movw %ax, %gs
/*
* This is a FAR JMP to the OS waking vector.
* The C code changes the address to be correct.
*/
.byte 0xea
__wakeup_offset = RELOCATED(.)
.word 0x0000
__wakeup_segment = RELOCATED(.)
.word 0x0000
.globl __wakeup_size
__wakeup_size:
.long . - __wakeup