diff options
Diffstat (limited to 'src/arch/x86/interface/syslinux/com32_wrapper.S')
| -rw-r--r-- | src/arch/x86/interface/syslinux/com32_wrapper.S | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/arch/x86/interface/syslinux/com32_wrapper.S b/src/arch/x86/interface/syslinux/com32_wrapper.S new file mode 100644 index 000000000..d59a3392c --- /dev/null +++ b/src/arch/x86/interface/syslinux/com32_wrapper.S @@ -0,0 +1,100 @@ +/* + * Copyright (C) 2008 Daniel Verkamp <daniel@drv.nu>. + * + * This program 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 2 of the + * License, or any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ) + +#include "librm.h" + + .text + + .code32 + .globl com32_farcall_wrapper +com32_farcall_wrapper: + movl $VIRTUAL(com32_farcall), %eax + jmp com32_wrapper + + .code32 + .globl com32_cfarcall_wrapper +com32_cfarcall_wrapper: + movl $VIRTUAL(com32_cfarcall), %eax + jmp com32_wrapper + + .code32 + .globl com32_intcall_wrapper +com32_intcall_wrapper: + movl $VIRTUAL(com32_intcall), %eax + /* fall through */ + + .code32 +com32_wrapper: + + /* Disable interrupts */ + cli + + /* Switch to internal virtual address space */ + call _phys_to_virt + +#ifdef __x86_64__ + + .code64 + + /* Preserve registers which are callee-save for COM32 (i386 API) */ + pushq %rdi + pushq %rsi + pushq %rbp + + /* Extract parameters from stack */ + movl 28(%rsp), %edi + movl 32(%rsp), %esi + movl 36(%rsp), %edx + + /* Align stack pointer */ + movq %rsp, %rbp + andq $~0x07, %rsp + + /* Call helper function */ + movslq %eax, %rax + call *%rax + + /* Restore stack pointer */ + movq %rbp, %rsp + + /* Restore registers */ + popq %rbp + popq %rsi + popq %rdi + +#else /* _x86_64 */ + + /* Call helper function */ + pushl 12(%esp) + pushl 12(%esp) + pushl 12(%esp) + call *%eax + addl $12, %esp + +#endif /* _x86_64 */ + + /* Switch to external flat physical address space */ + call _virt_to_phys + .code32 + + /* Reenable interrupts and return */ + sti + ret |