diff options
Diffstat (limited to 'src/arch/x86/lib/thread_switch.S')
-rw-r--r-- | src/arch/x86/lib/thread_switch.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/arch/x86/lib/thread_switch.S b/src/arch/x86/lib/thread_switch.S new file mode 100644 index 0000000..8de1948 --- /dev/null +++ b/src/arch/x86/lib/thread_switch.S @@ -0,0 +1,58 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2013 Google, Inc. + * + * 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; version 2 of the License. + * + * 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 St, Fifth Floor, Boston, MA 02110-1301 USA + */ +.code32 +.text + +/* + * stack layout after pushad: + * +------------+ + * | save stack | <-- esp + 0x28 + * +------------+ + * | new stack | <-- esp + 0x24 + * +------------+ + * | ret addr | <-- esp + 0x20 + * +------------+ + * | eax | <-- esp + 0x1c + * +------------+ + * | ecx | <-- esp + 0x18 + * +------------+ + * | edx | <-- esp + 0x14 + * +------------+ + * | ebx | <-- esp + 0x10 + * +------------+ + * | orig esp | <-- esp + 0x0c + * +------------+ + * | ebp | <-- esp + 0x08 + * +------------+ + * | esi | <-- esp + 0x04 + * +------------+ + * | edi | <-- esp + 0x00 + * +------------+ + */ +.globl switch_to_thread +switch_to_thread: + pusha + /* Save the current stack */ + movl 0x28(%esp), %ebx + movl %esp, (%ebx) + /* Switch to the new stack. */ + movl 0x24(%esp), %eax + movl %eax, %esp + popa + ret |