blob: 0a11141d33de0ce32158f34b7d1d5a5a01b52c69 [file] [log] [blame]
/*
* 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.
*/
#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,
asmlinkage void (*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];
}