1 /* 2 * Copyright (C) 2008 Daniel Verkamp <daniel (at) drv.nu>. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License as 6 * published by the Free Software Foundation; either version 2 of the 7 * License, or any later version. 8 * 9 * This program is distributed in the hope that it will be useful, but 10 * WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 19 FILE_LICENCE ( GPL2_OR_LATER ) 20 21 .text 22 .arch i386 23 .code32 24 25 .globl com32_farcall_wrapper 26 com32_farcall_wrapper: 27 28 movl $com32_farcall, %eax 29 jmp com32_wrapper 30 31 32 .globl com32_cfarcall_wrapper 33 com32_cfarcall_wrapper: 34 35 movl $com32_cfarcall, %eax 36 jmp com32_wrapper 37 38 39 .globl com32_intcall_wrapper 40 com32_intcall_wrapper: 41 42 movl $com32_intcall, %eax 43 /*jmp com32_wrapper*/ /* fall through */ 44 45 com32_wrapper: 46 47 /* Switch to internal virtual address space */ 48 call _phys_to_virt 49 50 mov %eax, (com32_helper_function) 51 52 /* Save external COM32 stack pointer */ 53 movl %esp, (com32_external_esp) 54 55 /* Copy arguments to caller-save registers */ 56 movl 12(%esp), %eax 57 movl 8(%esp), %ecx 58 movl 4(%esp), %edx 59 60 /* Switch to internal stack */ 61 movl (com32_internal_esp), %esp 62 63 /* Copy arguments to internal stack */ 64 pushl %eax 65 pushl %ecx 66 pushl %edx 67 68 call *(com32_helper_function) 69 70 /* Clean up stack */ 71 addl $12, %esp 72 73 /* Save internal stack pointer and restore external stack pointer */ 74 movl %esp, (com32_internal_esp) 75 movl (com32_external_esp), %esp 76 77 /* Switch to external flat physical address space */ 78 call _virt_to_phys 79 80 ret 81 82 83 .data 84 85 /* Internal gPXE virtual address space %esp */ 86 .globl com32_internal_esp 87 .lcomm com32_internal_esp, 4 88 89 /* External flat physical address space %esp */ 90 .globl com32_external_esp 91 .lcomm com32_external_esp, 4 92 93 /* Function pointer of helper to call */ 94 .lcomm com32_helper_function, 4 95
