74 lines
1.8 KiB
ArmAsm
74 lines
1.8 KiB
ArmAsm
|
/*
|
||
|
|
* GRUB -- GRand Unified Bootloader
|
||
|
|
* Copyright (C) 2013 Free Software Foundation, Inc.
|
||
|
|
*
|
||
|
|
* GRUB is free software: you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation, either version 3 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* GRUB is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <grub/offsets.h>
|
||
|
|
#include <grub/symbol.h>
|
||
|
|
#include <grub/machine/kernel.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* uboot_syscall():
|
||
|
|
* This function is effectively a veneer, so it cannot
|
||
|
|
* modify the stack or corrupt any registers other than
|
||
|
|
* r12 (ip). Furthermore it needs to restore r8 for
|
||
|
|
* U-Boot (Global Data Pointer) and preserve it for Grub.
|
||
|
|
*/
|
||
|
|
FUNCTION(grub_uboot_syscall)
|
||
|
|
str r8, transition_space
|
||
|
|
str lr, transition_space + 4
|
||
|
|
str r9, transition_space + 8
|
||
|
|
|
||
|
|
ldr ip, saved_registers_ptr
|
||
|
|
ldr r8, [ip, #4 * 8]
|
||
|
|
ldr r9, [ip, #4 * 9]
|
||
|
|
|
||
|
|
bl do_syscall
|
||
|
|
|
||
|
|
ldr r8, transition_space
|
||
|
|
ldr lr, transition_space + 4
|
||
|
|
ldr r9, transition_space + 8
|
||
|
|
|
||
|
|
bx lr
|
||
|
|
do_syscall:
|
||
|
|
|
||
|
|
ldr ip, grub_uboot_syscall_ptr
|
||
|
|
bx ip
|
||
|
|
|
||
|
|
FUNCTION(grub_uboot_return)
|
||
|
|
ldr ip, saved_registers_ptr
|
||
|
|
ldr sp, [ip, #4 * 4]
|
||
|
|
pop {r4-r12, lr}
|
||
|
|
mov sp, r12
|
||
|
|
bx lr
|
||
|
|
|
||
|
|
|
||
|
|
.align 3
|
||
|
|
|
||
|
|
@ GRUB context stack space
|
||
|
|
transition_space:
|
||
|
|
.long 0 @ r8
|
||
|
|
.long 0 @ lr
|
||
|
|
.long 0 @ r9
|
||
|
|
|
||
|
|
saved_registers_ptr:
|
||
|
|
.long EXT_C(grub_arm_saved_registers)
|
||
|
|
|
||
|
|
VARIABLE(grub_uboot_syscall_ptr)
|
||
|
|
.long 0 @
|
||
|
|
|
||
|
|
END
|