qemu/tests/tcg/i386/system/boot.S
Alex Bennée 40d6ee9450 tests/tcg/i386: add system mode Hello World test
This introduces the build framework for simple i386 system tests. The
first test is the eponymous "Hello World" which simply outputs the
text on the serial port and then exits.

I've included the framework for x86_64 but it is not in this series as
it is a work in progress.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-03-12 17:05:21 +00:00

173 lines
3.2 KiB
ArmAsm

/*
* i386 boot code, based on qemu-bmibug.
*
* Copyright 2019 Doug Gale
* Copyright 2019 Linaro
*
* This work is licensed under the terms of the GNU GPL, version 3 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*/
.section .head
/* Multi-boot header */
multiboot_st:
.int 0x1BADB002
.int 0x10000
.int -(0x10000+0x1BADB002)
// Load address
.int __load_st
.int __load_st
.int __load_en
.int __bss_en
.int _start
// mode
.int 0
// width
.int 0
// height
.int 0
// depth
.int 0
.code32
.section .text
/* Kernel Entry Point */
.global _start
_start:
// Setup stack ASAP
mov $stack_end,%esp
// Load GDT ASAP
lgdt gdtr
ljmp $0x8,$.Lloadcs
.Lloadcs:
mov $0x10,%eax
mov %eax,%ds
mov %eax,%es
mov %eax,%fs
mov %eax,%gs
mov %eax,%ss
// Fixup the IDT to the ridiculous i386 layout
xor %ebx,%ebx
.Lnextidt:
mov idt_00(,%ebx,8),%eax
shr $16,%eax
movw $0x8,idt_00+2(,%ebx,8)
movw $0x8E00,idt_00+4(,%ebx,8)
movw %ax,idt_00+6(,%ebx,8)
add $1,%ebx
cmp $32,%ebx
jl .Lnextidt
// Load IDTR
push $idt_00
push $((32 * 8 - 1) << 16)
lidt 2(%esp)
add $8,%esp
/*
* Don't worry about stack frame, assume everthing
* is garbage when we return, we won't need it.
*/
call main
/* output any non-zero result in eax to isa-debug-exit device */
test %al, %al
jz 1f
out %ax, $0xf4
1: /* QEMU ACPI poweroff */
mov $0x604,%edx
mov $0x2000,%eax
out %ax,%dx
hlt
jmp 1b
/*
* Helper Functions
*/
/* Output a single character to serial port */
.global __sys_outc
__sys_outc:
pushl %ebp
movl %esp, %ebp
out %al,$0xE9
movl %ebp, %esp
popl %ebp
ret
/* Interrupt Descriptor Table */
.section .data
.align 16
idt_00: .int 0, 0
idt_01: .int 0, 0
idt_02: .int 0, 0
idt_03: .int 0, 0
idt_04: .int 0, 0
idt_05: .int 0, 0
idt_06: .int 0, 0 /* intr_6_opcode, Invalid Opcode */
idt_07: .int 0, 0
idt_08: .int 0, 0
idt_09: .int 0, 0
idt_0A: .int 0, 0
idt_0B: .int 0, 0
idt_0C: .int 0, 0
idt_0D: .int 0, 0
idt_0E: .int 0, 0
idt_0F: .int 0, 0
idt_10: .int 0, 0
idt_11: .int 0, 0
idt_12: .int 0, 0
idt_13: .int 0, 0
idt_14: .int 0, 0
idt_15: .int 0, 0
idt_16: .int 0, 0
idt_17: .int 0, 0
idt_18: .int 0, 0
idt_19: .int 0, 0
idt_1A: .int 0, 0
idt_1B: .int 0, 0
idt_1C: .int 0, 0
idt_1D: .int 0, 0
idt_1E: .int 0, 0
idt_1F: .int 0, 0
gdt:
.short 0
gdtr:
.short gdt_en - gdt - 1
.int gdt
// Code
.short 0xFFFF
.short 0
.byte 0
.byte 0x9b
.byte 0xCF
.byte 0
// Data
.short 0xFFFF
.short 0
.byte 0
.byte 0x93
.byte 0xCF
.byte 0
gdt_en:
.section .bss
.align 16
stack: .space 65536
stack_end: