diff options
Diffstat (limited to 'qemu/roms/ipxe/src/arch/i386/core/patch_cf.S')
| -rw-r--r-- | qemu/roms/ipxe/src/arch/i386/core/patch_cf.S | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/arch/i386/core/patch_cf.S b/qemu/roms/ipxe/src/arch/i386/core/patch_cf.S new file mode 100644 index 000000000..97a62f494 --- /dev/null +++ b/qemu/roms/ipxe/src/arch/i386/core/patch_cf.S @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2009 H. Peter Anvin <hpa@zytor.com> + * + * 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 (at your option) 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 + .code16 + +/**************************************************************************** + * Set/clear CF on the stack as appropriate, assumes stack is as it should + * be immediately before IRET + **************************************************************************** + */ + .section ".text16", "ax", @progbits + .globl patch_cf +patch_cf: + pushw %bp + movw %sp, %bp + setc 8(%bp) /* Set/reset CF; clears PF, AF, ZF, SF */ + popw %bp + ret + .size patch_cf, . - patch_cf |