zephyr/arch/x86/core/common.S

57 lines
1.5 KiB
ArmAsm

/*
* Copyright (c) 2019 Intel Corporation
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/arch/x86/multiboot.h>
/*
* This is included by ia32/crt0.S and intel64/locore.S
* at their 32-bit entry points to cover common ground.
*/
#ifdef CONFIG_MULTIBOOT_INFO
/*
* If we were loaded by a multiboot-compliant loader, then EAX
* contains MULTIBOOT_EAX_MAGIC and EBX points to a valid 'struct
* multiboot_info'; otherwise EBX is just junk. Check EAX early
* before it's clobbered and leave a sentinel (0) in EBX if invalid.
* The valid in EBX will be the argument to z_x86_prep_c(), so the
* subsequent code must, of course, be sure to preserve it meanwhile.
*/
cmpl $MULTIBOOT_EAX_MAGIC, %eax
je 1f
xorl %ebx, %ebx
1:
#endif
#ifdef CONFIG_PIC_DISABLE
/*
* "Disable" legacy i8259 interrupt controllers. Note that we
* can't actually disable them, but we mask all their interrupt
* sources which is effectively the same thing (almost).
*/
movb $0xff, %al
outb %al, $0x21
outb %al, $0xA1
#endif
#ifdef CONFIG_MULTIBOOT
jmp 1f
.align 4
.long MULTIBOOT_HEADER_MAGIC
.long MULTIBOOT_HEADER_FLAGS
.long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
#ifdef CONFIG_MULTIBOOT_FRAMEBUF
.fill 5,4,0 /* (unused exec layout) */
.long 0 /* linear graphics mode */
.long CONFIG_MULTIBOOT_FRAMEBUF_X /* width */
.long CONFIG_MULTIBOOT_FRAMEBUF_Y /* height */
.long 32 /* depth */
#endif /* CONFIG_MULTIBOOT_FRAMEBUF */
1:
#endif