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603 lines
15 KiB
ArmAsm
603 lines
15 KiB
ArmAsm
// 这是内核执行头程序
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// Created by longjin.
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// 2022/01/20
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#include "common/asm.h"
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// 以下是来自 multiboot2 规范的定义
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// How many bytes from the start of the file we search for the header.
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#define MULTIBOOT_SEARCH 32768
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#define MULTIBOOT_HEADER_ALIGN 8
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// The magic field should contain this.
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#define MULTIBOOT2_HEADER_MAGIC 0xe85250d6
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// This should be in %eax.
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#define MULTIBOOT2_BOOTLOADER_MAGIC 0x36d76289
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// Alignment of multiboot modules.
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#define MULTIBOOT_MOD_ALIGN 0x00001000
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// Alignment of the multiboot info structure.
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#define MULTIBOOT_INFO_ALIGN 0x00000008
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// Flags set in the 'flags' member of the multiboot header.
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#define MULTIBOOT_TAG_ALIGN 8
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#define MULTIBOOT_TAG_TYPE_END 0
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#define MULTIBOOT_TAG_TYPE_CMDLINE 1
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#define MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME 2
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#define MULTIBOOT_TAG_TYPE_MODULE 3
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#define MULTIBOOT_TAG_TYPE_BASIC_MEMINFO 4
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#define MULTIBOOT_TAG_TYPE_BOOTDEV 5
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#define MULTIBOOT_TAG_TYPE_MMAP 6
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#define MULTIBOOT_TAG_TYPE_VBE 7
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#define MULTIBOOT_TAG_TYPE_FRAMEBUFFER 8
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#define MULTIBOOT_TAG_TYPE_ELF_SECTIONS 9
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#define MULTIBOOT_TAG_TYPE_APM 10
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#define MULTIBOOT_TAG_TYPE_EFI32 11
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#define MULTIBOOT_TAG_TYPE_EFI64 12
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#define MULTIBOOT_TAG_TYPE_SMBIOS 13
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#define MULTIBOOT_TAG_TYPE_ACPI_OLD 14
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#define MULTIBOOT_TAG_TYPE_ACPI_NEW 15
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#define MULTIBOOT_TAG_TYPE_NETWORK 16
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#define MULTIBOOT_TAG_TYPE_EFI_MMAP 17
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#define MULTIBOOT_TAG_TYPE_EFI_BS 18
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#define MULTIBOOT_TAG_TYPE_EFI32_IH 19
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#define MULTIBOOT_TAG_TYPE_EFI64_IH 20
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#define MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR 21
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#define MULTIBOOT_HEADER_TAG_END 0
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#define MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST 1
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#define MULTIBOOT_HEADER_TAG_ADDRESS 2
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS 3
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#define MULTIBOOT_HEADER_TAG_CONSOLE_FLAGS 4
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#define MULTIBOOT_HEADER_TAG_FRAMEBUFFER 5
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#define MULTIBOOT_HEADER_TAG_MODULE_ALIGN 6
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#define MULTIBOOT_HEADER_TAG_EFI_BS 7
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI32 8
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI64 9
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#define MULTIBOOT_HEADER_TAG_RELOCATABLE 10
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#define MULTIBOOT_ARCHITECTURE_I386 0
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#define MULTIBOOT_ARCHITECTURE_MIPS32 4
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#define MULTIBOOT_HEADER_TAG_OPTIONAL 1
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#define MULTIBOOT_LOAD_PREFERENCE_NONE 0
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#define MULTIBOOT_LOAD_PREFERENCE_LOW 1
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#define MULTIBOOT_LOAD_PREFERENCE_HIGH 2
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#define MULTIBOOT_CONSOLE_FLAGS_CONSOLE_REQUIRED 1
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#define MULTIBOOT_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED 2
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// 以下是来自 multiboot2 规范的定义
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// How many bytes from the start of the file we search for the header.
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#define MULTIBOOT_SEARCH 32768
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#define MULTIBOOT_HEADER_ALIGN 8
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// The magic field should contain this.
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#define MULTIBOOT2_HEADER_MAGIC 0xe85250d6
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// This should be in %eax.
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#define MULTIBOOT2_BOOTLOADER_MAGIC 0x36d76289
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// Alignment of multiboot modules.
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#define MULTIBOOT_MOD_ALIGN 0x00001000
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// Alignment of the multiboot info structure.
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#define MULTIBOOT_INFO_ALIGN 0x00000008
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// Flags set in the 'flags' member of the multiboot header.
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#define MULTIBOOT_TAG_ALIGN 8
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#define MULTIBOOT_TAG_TYPE_END 0
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#define MULTIBOOT_TAG_TYPE_CMDLINE 1
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#define MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME 2
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#define MULTIBOOT_TAG_TYPE_MODULE 3
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#define MULTIBOOT_TAG_TYPE_BASIC_MEMINFO 4
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#define MULTIBOOT_TAG_TYPE_BOOTDEV 5
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#define MULTIBOOT_TAG_TYPE_MMAP 6
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#define MULTIBOOT_TAG_TYPE_VBE 7
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#define MULTIBOOT_TAG_TYPE_FRAMEBUFFER 8
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#define MULTIBOOT_TAG_TYPE_ELF_SECTIONS 9
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#define MULTIBOOT_TAG_TYPE_APM 10
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#define MULTIBOOT_TAG_TYPE_EFI32 11
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#define MULTIBOOT_TAG_TYPE_EFI64 12
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#define MULTIBOOT_TAG_TYPE_SMBIOS 13
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#define MULTIBOOT_TAG_TYPE_ACPI_OLD 14
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#define MULTIBOOT_TAG_TYPE_ACPI_NEW 15
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#define MULTIBOOT_TAG_TYPE_NETWORK 16
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#define MULTIBOOT_TAG_TYPE_EFI_MMAP 17
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#define MULTIBOOT_TAG_TYPE_EFI_BS 18
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#define MULTIBOOT_TAG_TYPE_EFI32_IH 19
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#define MULTIBOOT_TAG_TYPE_EFI64_IH 20
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#define MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR 21
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#define MULTIBOOT_HEADER_TAG_END 0
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#define MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST 1
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#define MULTIBOOT_HEADER_TAG_ADDRESS 2
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS 3
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#define MULTIBOOT_HEADER_TAG_CONSOLE_FLAGS 4
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#define MULTIBOOT_HEADER_TAG_FRAMEBUFFER 5
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#define MULTIBOOT_HEADER_TAG_MODULE_ALIGN 6
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#define MULTIBOOT_HEADER_TAG_EFI_BS 7
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI32 8
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#define MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS_EFI64 9
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#define MULTIBOOT_HEADER_TAG_RELOCATABLE 10
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#define MULTIBOOT_ARCHITECTURE_I386 0
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#define MULTIBOOT_ARCHITECTURE_MIPS32 4
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#define MULTIBOOT_HEADER_TAG_OPTIONAL 1
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#define MULTIBOOT_LOAD_PREFERENCE_NONE 0
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#define MULTIBOOT_LOAD_PREFERENCE_LOW 1
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#define MULTIBOOT_LOAD_PREFERENCE_HIGH 2
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#define MULTIBOOT_CONSOLE_FLAGS_CONSOLE_REQUIRED 1
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#define MULTIBOOT_CONSOLE_FLAGS_EGA_TEXT_SUPPORTED 2
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// 直接用 -m64 编译出来的是 64 位代码，
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// 但是启动后的机器是 32 位的，相当于在 32 位机器上跑 64 位程序。
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// 得加一层跳转到 64 位的 -m32 代码，开启 long 模式后再跳转到以 -m64 编译的代码中
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// 对于 x86_64，需要在启动阶段进入长模式(IA32E)，这意味着需要一个临时页表
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// See https://wiki.osdev.org/Creating_a_64-bit_kernel:
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// With a 32-bit bootstrap in your kernel
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// 这部分是从保护模式启动 long 模式的代码
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// 工作在 32bit
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// 声明这一段代码以 32 位模式编译
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.code32
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// multiboot2 文件头
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// 计算头长度
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.SET HEADER_LENGTH, multiboot_header_end - multiboot_header
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// 计算校验和
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.SET CHECKSUM, -(MULTIBOOT2_HEADER_MAGIC + MULTIBOOT_ARCHITECTURE_I386 + HEADER_LENGTH)
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// 8 字节对齐
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.align MULTIBOOT_HEADER_ALIGN
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// 声明所属段
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.section .multiboot_header
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multiboot_header:
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// 魔数
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.long MULTIBOOT2_HEADER_MAGIC
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// 架构
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.long MULTIBOOT_ARCHITECTURE_I386
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// 头长度
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.long HEADER_LENGTH
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// 校验和
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.long CHECKSUM
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// 添加其它内容在此，详细信息见 Multiboot2 Specification version 2.0.pdf
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// 设置帧缓冲区
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.align 8
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framebuffer_tag_start:
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.short MULTIBOOT_HEADER_TAG_FRAMEBUFFER
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.short MULTIBOOT_HEADER_TAG_OPTIONAL
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.long framebuffer_tag_end - framebuffer_tag_start
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.long 1440
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.long 900
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.long 32
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framebuffer_tag_end:
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.align 8
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.short MULTIBOOT_HEADER_TAG_END
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// 结束标记
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.short 0
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.long 8
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multiboot_header_end:
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// 临时页表 4KB/页
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.section .data
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.align 0x1000
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.global pml4
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pml4:
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.skip 0x1000
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pdpt:
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.skip 0x1000
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pd:
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.skip 0x1000
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pt:
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.skip 0x1000
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// 临时 GDT
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.align 16
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gdt64:
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null_desc:
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.short 0xFFFF
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.short 0
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.byte 0
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.byte 0
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.byte 0
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.byte 0
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code_desc:
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.short 0
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.short 0
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.byte 0
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.byte 0x9A
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.byte 0x20
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.byte 0
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data_desc:
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.short 0
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.short 0
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.byte 0
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.byte 0x92
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.byte 0
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.byte 0
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user_code_desc:
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.short 0
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.short 0
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.byte 0
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.byte 0xFA
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.byte 0x20
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.byte 0
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user_data_desc:
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.short 0
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.short 0
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.byte 0
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.byte 0xF2
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.byte 0
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.byte 0
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gdt64_pointer:
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.short gdt64_pointer-gdt64-1
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.quad gdt64
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gdt64_pointer64:
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.short gdt64_pointer-gdt64-1
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.quad gdt64
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.section .text
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.global _start
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.type _start, @function
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# 在 multiboot2.cpp 中定义
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.extern boot_info_addr
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.extern multiboot2_magic
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.extern _start64
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_start:
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// 关中断
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cli
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// multiboot2_info 结构体指针
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mov %ebx, boot_info_addr
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// 魔数
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mov %eax, multiboot2_magic
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/ 从保护模式跳转到长模式
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// 1. 允许 PAE
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mov %cr4, %eax
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or $(1<<5), %eax
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mov %eax, %cr4
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// 2. 设置临时页表
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// 最高级
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mov $pml4, %eax
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mov $pdpt, %ebx
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or $0x3, %ebx
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mov %ebx, 0(%eax)
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// 次级
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mov $pdpt, %eax
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mov $pd, %ebx
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or $0x3, %ebx
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mov %ebx, 0(%eax)
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// 次低级
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mov $pd, %eax
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mov $pt, %ebx
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or $0x3, %ebx
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mov %ebx, 0(%eax)
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// 最低级
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// 循环 512 次，填满一页
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mov $512, %ecx
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mov $pt, %eax
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mov $0x3, %ebx
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.fill_pt:
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mov %ebx, 0(%eax)
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add $0x1000, %ebx
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add $8, %eax
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loop .fill_pt
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// 填写 CR3
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mov $pml4, %eax
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mov %eax, %cr3
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// 3. 切换到 long 模式
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mov $0xC0000080, %ecx
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rdmsr
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or $(1<<8), %eax
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wrmsr
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// 4. 开启分页
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mov %cr0, %eax
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or $(1<<31), %eax
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mov %eax, %cr0
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// 5. 重新设置 GDT
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mov $gdt64_pointer, %eax
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lgdt 0(%eax)
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// 6. 跳转到 64 位代码执行
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jmp $0x8, $_start64
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hlt
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ret
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.section .text
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.code64
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.global _start64
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.type _start64, @function
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.extern Start_Kernel
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ENTRY(_start64)
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// 初始化寄存器
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mov $0x10, %ax
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mov %ax, %ds
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mov %ax, %es
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mov %ax, %fs
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mov %ax, %ss
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mov $0x7e00, %esp
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// === 加载GDTR ====
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lgdt GDT_POINTER(%rip) //这里我没搞明白rip相对寻址, 看了文档，大概是用来实现PIC的（position independent code）
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// === 加载IDTR ====
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lidt IDT_POINTER(%rip)
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mov $0x10, %ax
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mov %ax, %ds
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mov %ax, %es
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mov %ax, %fs
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mov %ax, %ss
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mov %ax, %gs
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movq $0x7e00, %rsp
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// 2. 设置临时页表
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// 最高级
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mov $__PML4E, %eax
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mov $__PDPTE, %ebx
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or $0x3, %ebx
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mov %ebx, 0(%eax)
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// 次级
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mov $__PDPTE, %eax
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mov $__PDE, %ebx
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or $0x3, %ebx
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mov %ebx, 0(%eax)
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// ==== 加载CR3寄存器
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movq $__PML4E, %rax //设置页目录基地址
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movq %rax, %cr3
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movq switch_seg(%rip), %rax
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// 由于ljmp和lcall在GAS中不受支持，因此我们需要先伪造函数调用现场，通过lret的方式，给它跳转过去。才能更新cs寄存器
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// 实在是太妙了！Amazing！
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pushq $0x08 //段选择子
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pushq %rax
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lretq
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// 64位模式的代码
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switch_seg:
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.quad entry64
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entry64:
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movq $0x10, %rax
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movq %rax, %ds
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movq %rax, %es
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movq %rax, %gs
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movq %rax, %ss
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movq _stack_start(%rip), %rsp //rsp的地址
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setup_IDT:
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leaq m_ignore_int(%rip), %rdx // 将ignore_int的地址暂时存到中段描述符的高8B
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movq $(0x08 << 16), %rax // 设置段选择子。由IDT结构和段选择子结构可知，本行设置段基地址为0x100000，TI=0,RPL=0
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movw %dx, %ax
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movq $ (0x8e00 << 32), %rcx // 设置Type=1110 P=1 DPL=00 0=0
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addq %rcx, %rax
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// 把ignore_int的地址填写到正确位置, rax存低8B， rdx存高8B
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movl %edx, %ecx
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shrl $16, %ecx // 去除低16位
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shlq $48, %rcx
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addq %rcx, %rax // 填写段内偏移31:16
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shrq $32, %rdx // （已经填写了32位，故右移32）
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leaq IDT_Table(%rip), %rdi // 获取中断描述符表的首地址，存储到rdi
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mov $256, %rcx // 初始化每个中断描述符
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repeat_set_idt:
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// ====== 循环，初始化总共256个中断描述符 ===
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movq %rax, (%rdi) // 保存低8B
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movq %rdx, 8(%rdi) // 保存高8B
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addq $0x10, %rdi // 转到下一个IDT表项
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dec %rcx
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jne repeat_set_idt
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SetUp_TSS64:
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// == 设置64位的任务状态段表 ===
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//rdx保存高8B， rax保存低8B
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leaq TSS64_Table(%rip), %rdx
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xorq %rax, %rax
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xorq %rcx, %rcx
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// 设置TSS描述符的47：40位为1000 1001
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movq $0x89, %rax
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shlq $40, %rax
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// 设置段基地址31:24
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movl %edx, %ecx
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shrl $24, %ecx
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shlq $56, %rcx
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addq %rcx, %rax
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xorq %rcx, %rcx
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// 设置段基地址23:00
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movl %edx, %ecx
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andl $0xffffff, %ecx // 清空ecx的中有效值的高8位（也就是上面已经赋值了的）
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shlq $16, %rcx
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addq %rcx, %rax
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addq $103, %rax // 设置段长度
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leaq GDT_Table(%rip), %rdi
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movq %rax, 80(%rdi) // 把低八B存储到GDT第10项
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shrq $32, %rdx
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movq %rdx, 88(%rdi) // 高8B存到GDT第11项
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// 装载任务状态段寄存器(已改为在main.c中使用load_TR宏进行装载)
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// mov $0x50, %ax // 设置起始地址为80
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// ltr %ax
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//now enable SSE and the like
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movq %cr0, %rax
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and $0xFFFB, %ax //clear coprocessor emulation CR0.EM
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or $0x2, %ax //set coprocessor monitoring CR0.MP
|
||
movq %rax, %cr0
|
||
movq %cr4, %rax
|
||
or $(3 << 9), %ax //set CR4.OSFXSR and CR4.OSXMMEXCPT at the same time
|
||
movq %rax, %cr4
|
||
|
||
call Start_Kernel
|
||
|
||
go_to_kernel:
|
||
.quad Start_Kernel
|
||
|
||
// ==== 异常/中断处理模块 ignore int： 忽略中断
|
||
m_ignore_int:
|
||
// 切换到c语言的ignore_int
|
||
movq go_to_ignore_int(%rip), %rax
|
||
pushq $0x08
|
||
pushq %rax
|
||
lretq
|
||
|
||
lretq
|
||
|
||
|
||
go_to_ignore_int:
|
||
.quad ignore_int
|
||
|
||
|
||
ENTRY(_stack_start)
|
||
.quad initial_proc_union + 32768
|
||
|
||
|
||
// 初始化页表
|
||
|
||
.align 0x1000 //设置为4k对齐
|
||
.org 0x1000 //设置页表位置为内核执行头程序的0x1000处
|
||
|
||
__PML4E:
|
||
.quad 0x103003 // 用户访问，可读写，已存在， 地址在31~12位
|
||
.fill 255,8,0
|
||
.quad 0x103003
|
||
.fill 255,8,0
|
||
|
||
.org 0x2000
|
||
|
||
__PDPTE:
|
||
|
||
.quad 0x104003 // 用户访问，可读写，已存在
|
||
.fill 511,8,0
|
||
|
||
.org 0x3000
|
||
|
||
__PDE:
|
||
|
||
.quad 0x000083 // 用户访问，可读写，已存在
|
||
.quad 0x200083
|
||
.quad 0x400083
|
||
.quad 0x600083
|
||
.quad 0x800083
|
||
.quad 0xa00083
|
||
.quad 0xc00083
|
||
.quad 0xe00083
|
||
.quad 0x1000083
|
||
.quad 0x1200083
|
||
.quad 0x1400083
|
||
.quad 0x1600083
|
||
.quad 0x1800083
|
||
.quad 0x1a00083
|
||
.quad 0x1c00083
|
||
.quad 0x1e00083
|
||
.quad 0x2000083
|
||
.quad 0x2200083
|
||
.quad 0x2400083
|
||
.quad 0x2600083
|
||
.quad 0x2800083
|
||
.quad 0x2a00083
|
||
.quad 0x2c00083
|
||
.quad 0x2e00083
|
||
.quad 0x3000083
|
||
.quad 0x3200083
|
||
.quad 0x3400083
|
||
.quad 0x3600083
|
||
|
||
|
||
.quad 0xe0000083 /*虚拟地址0x 3000000 初始情况下，帧缓冲区映射到这里*/
|
||
.quad 0xe0200083
|
||
.quad 0xe0400083
|
||
.quad 0xe0600083 /*0x1000000*/
|
||
.quad 0xe0800083
|
||
.quad 0xe0a00083
|
||
.quad 0xe0c00083
|
||
.quad 0xe0e00083
|
||
.quad 0xe1000083
|
||
.quad 0xe1200083
|
||
.quad 0xe1400083
|
||
.quad 0xe1600083
|
||
.quad 0xe1800083
|
||
.quad 0xe1a00083
|
||
.quad 0xe1c00083
|
||
.quad 0xe1e00083
|
||
.fill 468,8,0
|
||
|
||
// GDT表
|
||
.section .data
|
||
.align 16
|
||
.global GDT_Table // 使得GDT可以被外部程序引用或者访问
|
||
|
||
GDT_Table:
|
||
.quad 0x0000000000000000 // 0 空描述符 0x00
|
||
.quad 0x0020980000000000 // 1 内核64位代码段描述符 0x08
|
||
.quad 0x0000920000000000 // 2 内核64位数据段描述符 0x10
|
||
.quad 0x0000000000000000 // 3 用户32位代码段描述符 0x18
|
||
.quad 0x0000000000000000 // 4 用户32位数据段描述符 0x20
|
||
.quad 0x0020f80000000000 // 5 用户64位代码段描述符 0x28
|
||
.quad 0x0000f20000000000 // 6 用户64位数据段描述符 0x30
|
||
.quad 0x00cf9a000000ffff // 7 内核32位代码段描述符 0x38
|
||
.quad 0x00cf92000000ffff // 8 内核32位数据段描述符 0x40
|
||
.fill 10, 8, 0 // 10-11 TSS(跳过了第9段) 重复十次填充8字节的空间，赋值为0
|
||
GDT_END:
|
||
|
||
GDT_POINTER:
|
||
GDT_LIMIT: .word GDT_END - GDT_Table - 1 // GDT的大小
|
||
GDT_BASE: .quad GDT_Table
|
||
|
||
// IDT 表
|
||
.global IDT_Table
|
||
|
||
IDT_Table:
|
||
.fill 512, 8, 0 // 设置512*8字节的IDT表的空间
|
||
IDT_END:
|
||
|
||
IDT_POINTER:
|
||
IDT_LIMIT: .word IDT_END - IDT_Table - 1
|
||
IDT_BASE: .quad IDT_Table
|
||
|
||
// 64位的TSS表
|
||
.global TSS64_Table
|
||
|
||
TSS64_Table:
|
||
.fill 13, 8, 0
|
||
TSS64_END:
|
||
|
||
TSS64_POINTER:
|
||
TSS64_LIMIT: .word TSS64_END - TSS64_Table - 1
|
||
TSS64_BASE: .quad TSS64_Table |