diff options
Diffstat (limited to 'roms/ipxe/src/arch/i386/interface/syslinux/com32_wrapper.S')
-rw-r--r-- | roms/ipxe/src/arch/i386/interface/syslinux/com32_wrapper.S | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/roms/ipxe/src/arch/i386/interface/syslinux/com32_wrapper.S b/roms/ipxe/src/arch/i386/interface/syslinux/com32_wrapper.S new file mode 100644 index 00000000..c9d1452b --- /dev/null +++ b/roms/ipxe/src/arch/i386/interface/syslinux/com32_wrapper.S @@ -0,0 +1,97 @@ +/* + * 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 ) + + .text + .arch i386 + .code32 + + .globl com32_farcall_wrapper +com32_farcall_wrapper: + + movl $com32_farcall, %eax + jmp com32_wrapper + + + .globl com32_cfarcall_wrapper +com32_cfarcall_wrapper: + + movl $com32_cfarcall, %eax + jmp com32_wrapper + + + .globl com32_intcall_wrapper +com32_intcall_wrapper: + + movl $com32_intcall, %eax + /*jmp com32_wrapper*/ /* fall through */ + +com32_wrapper: + cli + + /* Switch to internal virtual address space */ + call _phys_to_virt + + mov %eax, (com32_helper_function) + + /* Save external COM32 stack pointer */ + movl %esp, (com32_external_esp) + + /* Copy arguments to caller-save registers */ + movl 12(%esp), %eax + movl 8(%esp), %ecx + movl 4(%esp), %edx + + /* Switch to internal stack */ + movl (com32_internal_esp), %esp + + /* Copy arguments to internal stack */ + pushl %eax + pushl %ecx + pushl %edx + + call *(com32_helper_function) + + /* Clean up stack */ + addl $12, %esp + + /* Save internal stack pointer and restore external stack pointer */ + movl %esp, (com32_internal_esp) + movl (com32_external_esp), %esp + + /* Switch to external flat physical address space */ + call _virt_to_phys + + sti + ret + + + .data + +/* Internal iPXE virtual address space %esp */ +.globl com32_internal_esp +.lcomm com32_internal_esp, 4 + +/* External flat physical address space %esp */ +.globl com32_external_esp +.lcomm com32_external_esp, 4 + +/* Function pointer of helper to call */ +.lcomm com32_helper_function, 4 |