u-boot/arch/x86/cpu/call32.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

63 lines
1.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* (C) Copyright 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#include <asm/global_data.h>
#include <asm/msr-index.h>
#include <asm/processor-flags.h>
/*
* rdi - 32-bit code segment selector
* rsi - target address
* rdx - table address (0 if none)
*/
.code64
.globl cpu_call32
cpu_call32:
cli
/* Save table pointer */
mov %edx, %ebx
/*
* Debugging option, this outputs characters to the console UART
* mov $0x3f8,%edx
* mov $'a',%al
* out %al,(%dx)
*/
pushf
push %rdi /* 32-bit code segment */
lea compat(%rip), %rax
push %rax
.byte 0x48 /* REX prefix to force 64-bit far return */
retf
.code32
compat:
/*
* We are now in compatibility mode with a default operand size of
* 32 bits. First disable paging.
*/
movl %cr0, %eax
andl $~X86_CR0_PG, %eax
movl %eax, %cr0
/* Invalidate TLB */
xorl %eax, %eax
movl %eax, %cr3
/* Disable Long mode in EFER (Extended Feature Enable Register) */
movl $MSR_EFER, %ecx
rdmsr
btr $_EFER_LME, %eax
wrmsr
/* Set up table pointer for _x86boot_start */
mov %ebx, %ecx
/* Jump to the required target */
pushl %edi /* 32-bit code segment */
pushl %esi /* 32-bit target address */
retf