61 lines
1.2 KiB
ArmAsm
61 lines
1.2 KiB
ArmAsm
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||
|
|
/*
|
||
|
|
* EFI call stub for IA32.
|
||
|
|
*
|
||
|
|
* This stub allows us to make EFI calls in physical mode with interrupts
|
||
|
|
* turned off.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/linkage.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <asm/asm-offsets.h>
|
||
|
|
#include <asm/page_types.h>
|
||
|
|
|
||
|
|
__INIT
|
||
|
|
SYM_FUNC_START(efi_call_svam)
|
||
|
|
push %ebp
|
||
|
|
movl %esp, %ebp
|
||
|
|
push %ebx
|
||
|
|
|
||
|
|
push 16(%esp)
|
||
|
|
push 16(%esp)
|
||
|
|
push %ecx
|
||
|
|
push %edx
|
||
|
|
movl %eax, %ebx // &systab_phys->runtime
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Switch to the flat mapped alias of this routine, by jumping to the
|
||
|
|
* address of label '1' after subtracting PAGE_OFFSET from it.
|
||
|
|
*/
|
||
|
|
movl $1f, %edx
|
||
|
|
subl $__PAGE_OFFSET, %edx
|
||
|
|
jmp *%edx
|
||
|
|
1:
|
||
|
|
|
||
|
|
/* disable paging */
|
||
|
|
movl %cr0, %edx
|
||
|
|
andl $0x7fffffff, %edx
|
||
|
|
movl %edx, %cr0
|
||
|
|
|
||
|
|
/* convert the stack pointer to a flat mapped address */
|
||
|
|
subl $__PAGE_OFFSET, %esp
|
||
|
|
|
||
|
|
/* call the EFI routine */
|
||
|
|
movl (%eax), %eax
|
||
|
|
call *EFI_svam(%eax)
|
||
|
|
|
||
|
|
/* grab the virtually remapped EFI runtime services table pointer */
|
||
|
|
movl (%ebx), %ecx
|
||
|
|
movl 36(%esp), %edx // &efi.runtime
|
||
|
|
movl %ecx, (%edx)
|
||
|
|
|
||
|
|
/* re-enable paging */
|
||
|
|
movl %cr0, %edx
|
||
|
|
orl $0x80000000, %edx
|
||
|
|
movl %edx, %cr0
|
||
|
|
|
||
|
|
movl 16(%esp), %ebx
|
||
|
|
leave
|
||
|
|
RET
|
||
|
|
SYM_FUNC_END(efi_call_svam)
|