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-rw-r--r--src/arch/x86/thread.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/src/arch/x86/thread.c b/src/arch/x86/thread.c
new file mode 100644
index 0000000000..f81a2d20ca
--- /dev/null
+++ b/src/arch/x86/thread.c
@@ -0,0 +1,65 @@
+/*
+ * 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.
+ */
+
+#include <thread.h>
+
+/* The stack frame looks like the following after a pushad instruction. */
+struct pushad_regs {
+ uint32_t edi; /* Offset 0x00 */
+ uint32_t esi; /* Offset 0x04 */
+ uint32_t ebp; /* Offset 0x08 */
+ uint32_t esp; /* Offset 0x0c */
+ uint32_t ebx; /* Offset 0x10 */
+ uint32_t edx; /* Offset 0x14 */
+ uint32_t ecx; /* Offset 0x18 */
+ uint32_t eax; /* Offset 0x1c */
+};
+
+static inline uintptr_t push_stack(uintptr_t cur_stack, uintptr_t value)
+{
+ uintptr_t *addr;
+
+ cur_stack -= sizeof(value);
+ addr = (uintptr_t *)cur_stack;
+ *addr = value;
+ return cur_stack;
+}
+
+void arch_prepare_thread(struct thread *t,
+ void asmlinkage (*thread_entry)(void *), void *arg)
+{
+ uintptr_t stack = t->stack_current;
+
+ /* Imitate thread_entry(t) with return address of 0. thread_entry()
+ * is assumed to never return. */
+ stack = push_stack(stack, (uintptr_t)arg);
+ stack = push_stack(stack, (uintptr_t)0);
+ stack = push_stack(stack, (uintptr_t)thread_entry);
+ /* Make room for the registers. Ignore intial values. */
+ stack -= sizeof(struct pushad_regs);
+
+ t->stack_current = stack;
+}
+
+void *arch_get_thread_stackbase(void)
+{
+ /* defined in c_start.S */
+ extern u8 thread_stacks[];
+ return &thread_stacks[0];
+}