diff options
Diffstat (limited to 'src/kernel/boot.asm')
| -rw-r--r-- | src/kernel/boot.asm | 107 |
1 files changed, 37 insertions, 70 deletions
diff --git a/src/kernel/boot.asm b/src/kernel/boot.asm index ef6bf0e..9fc06ed 100644 --- a/src/kernel/boot.asm +++ b/src/kernel/boot.asm @@ -1,72 +1,39 @@ -global start ; Make start available to linker -extern kernel_main ; Get main function from kernel.c - -; Set Multiboot headers for GRUB -MODULEALIGN equ 1<<0 -MEMINFO equ 1<<1 -FLAGS equ MODULEALIGN | MEMINFO -MAGIC equ 0x1BADB002 -CHECKSUM equ -(MAGIC + FLAGS) - -; Set virtual base address of kernel space -KERNEL_VIRTUAL_BASE equ 0xC0000000 ; 3GB -KERNEL_PAGE_NUMBER equ (KERNEL_VIRTUAL_BASE >> 22) ; Page directory index of kernel's 4MB PTE. - -section .data -align 0x1000 -BootPageDirectory: - ; Create page directory entry to identity-map the first 4MB of the 32-bit physical address space. - dd 0x00000083 - times (KERNEL_PAGE_NUMBER - 1) dd 0 - ; Create 4MB page directory entry to contain the kernel - dd 0x00000083 - times (1024 - KERNEL_PAGE_NUMBER - 1) dd 0 - -section .text -align 4 -MultiBootHeader: - dd MAGIC - dd FLAGS - dd CHECKSUM - -; Reserve 16k for initial kernel stack space -STACKSIZE equ 0x4000 - -; Set up entry point for linker -loader equ (start - 0xC0000000) -global loader +[bits 32] +global start start: - ; Using physical addresses for now - mov ecx, (BootPageDirectory - KERNEL_VIRTUAL_BASE) - mov cr3, ecx ; Load Page Directory Base Register - - mov ecx, cr4 - or ecx, 0x00000010 ; Set PSE in CR4 to enable 4MB pages - mov cr4, ecx - - mov ecx, cr0 - or ecx, 0x80000000 ; Enable paging - mov cr0, ecx - - ; Long jump to StartInHigherHalf - lea ecx, [StartInHigherHalf] - jmp ecx - -StartInHigherHalf: - mov dword [BootPageDirectory], 0 - invlpg [0] - - mov esp, stack+STACKSIZE ; Set up the stack - push eax ; Pass Multiboot magic number - - ; Pass Multiboot info structure - push ebx - add ebx, KERNEL_VIRTUAL_BASE - push ebx - + mov esp, _sys_stack ; Points stack to stack area + jmp stublet + +; Align with 4 Bytes +ALIGN 4 +mboot: + ; Multiboot macros + MULTIBOOT_PAGE_ALIGN equ 1<<0 + MULTIBOOT_MEMORY_INFO equ 1<<1 + MULTIBOOT_AOUT_KLUDGE equ 1<<16 + MULTIBOOT_HEADER_MAGIC equ 0x1BADB002 + MULTIBOOT_HEADER_FLAGS equ MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO | MULTIBOOT_AOUT_KLUDGE + MULTIBOOT_CHECKSUM equ -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) + EXTERN code, bss, end + + ; GRUB Multiboot header + dd MULTIBOOT_HEADER_MAGIC + dd MULTIBOOT_HEADER_FLAGS + dd MULTIBOOT_CHECKSUM + + ; AOUT kludge + dd mboot + dd code + dd bss + dd end + dd start + +; Endless loop +stublet: + extern kernel_main call kernel_main - hlt + jmp $ %include "src/kernel/gdt/gdt.asm" @@ -78,7 +45,7 @@ StartInHigherHalf: %include "src/kernel/interact.asm" -section .bss -align 32 -stack: - resb STACKSIZE ; reserve 16k stack on a uint64_t boundary +; Store the stack +SECTION .bss + resb 8192 ; Reserve 8KiB +_sys_stack:
\ No newline at end of file |