threeeye
bc1d038eac
Squashed backup commit (no shallow-clone history issues) of xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2 branch, upstream commit 9eece662e) plus all fixes applied to get everpal_defconfig building clean against a modern (GCC 15.2.0) toolchain -- see the previous commit message on the lineage-23.2 branch (also in this repo history is not available here since this is a squashed snapshot; full incremental history lives in the local DL380 checkout and the upstream GitHub remote). Upstream: https://github.com/xiaomi-mt6833-dev/kernel_xiaomi_mt6833 (lineage-23.2)
68 lines
1.3 KiB
ArmAsm
68 lines
1.3 KiB
ArmAsm
/*
|
|
* thunks.S - assembly helpers for mixed-bitness code
|
|
* Copyright (c) 2015 Andrew Lutomirski
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope 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.
|
|
*
|
|
* These are little helpers that make it easier to switch bitness on
|
|
* the fly.
|
|
*/
|
|
|
|
.text
|
|
|
|
.global call32_from_64
|
|
.type call32_from_64, @function
|
|
call32_from_64:
|
|
// rdi: stack to use
|
|
// esi: function to call
|
|
|
|
// Save registers
|
|
pushq %rbx
|
|
pushq %rbp
|
|
pushq %r12
|
|
pushq %r13
|
|
pushq %r14
|
|
pushq %r15
|
|
pushfq
|
|
|
|
// Switch stacks
|
|
mov %rsp,(%rdi)
|
|
mov %rdi,%rsp
|
|
|
|
// Switch to compatibility mode
|
|
pushq $0x23 /* USER32_CS */
|
|
pushq $1f
|
|
lretq
|
|
|
|
1:
|
|
.code32
|
|
// Call the function
|
|
call *%esi
|
|
// Switch back to long mode
|
|
jmp $0x33,$1f
|
|
.code64
|
|
|
|
1:
|
|
// Restore the stack
|
|
mov (%rsp),%rsp
|
|
|
|
// Restore registers
|
|
popfq
|
|
popq %r15
|
|
popq %r14
|
|
popq %r13
|
|
popq %r12
|
|
popq %rbp
|
|
popq %rbx
|
|
|
|
ret
|
|
|
|
.size call32_from_64, .-call32_from_64
|