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u-boot/arch/x86/cpu/call32.S
Andy Shevchenko 940185910f x86: call32: Append appropriate suffixes
Assembler is not happy:

arch/x86/cpu/call32.S: Assembler messages:
arch/x86/cpu/call32.S:36: Warning: no instruction mnemonic suffix given and no register operands; using default for `retf'

Fix this by adding appropriate suffixes to the assembler commands.

Fixes: 6f92ed8f1a ("x86: Add a way to call 32-bit code from 64-bit mode")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-08-03 10:46:56 +08:00

62 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
retfq
.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 */
retfl