Reorganizing

1 files changed, 0 insertions, 163 deletions

diff --git a/src/arch/x86_64/boot.asm b/src/arch/x86_64/boot.asm
deleted file mode 100644
index 2e334a8..0000000
--- a/src/arch/x86_64/boot.asm
+++ /dev/null
@@ -1,163 +0,0 @@
-global start
-extern long_mode_start
-
-section .text
-bits 32
-start:
-    mov esp, stack_top
-
-    call check_multiboot
-    call check_cpuid
-    call check_long_mode
-
-    call set_up_page_tables
-    call enable_paging
-
-    ; load the 64-bit GDT
-    lgdt [gdt64.pointer]
-
-    jmp gdt64.code:long_mode_start
-
-    ; print `OK` to screen
-    mov dword [0xb8000], 0x2f4b2f4f
-    hlt
-
-check_multiboot:
-    cmp eax, 0x36d76289
-    jne .no_multiboot
-    ret
-.no_multiboot:
-    mov al, "0"
-    jmp error
-
-check_cpuid:
-    ; Check if CPUID is supported by attempting to flip the ID bit (bit 21)
-    ; in the FLAGS register. If we can flip it, CPUID is available.
-
-    ; Copy FLAGS in to EAX via stack
-    pushfd
-    pop eax
-
-    ; Copy to ECX as well for comparing later on
-    mov ecx, eax
-
-    ; Flip the ID bit
-    xor eax, 1 << 21
-
-    ; Copy EAX to FLAGS via the stack
-    push eax
-    popfd
-
-    ; Copy FLAGS back to EAX (with the flipped bit if CPUID is supported)
-    pushfd
-    pop eax
-
-    ; Restore FLAGS from the old version stored in ECX (i.e. flipping the
-    ; ID bit back if it was ever flipped).
-    push ecx
-    popfd
-
-    ; Compare EAX and ECX. If they are equal then that means the bit
-    ; wasn't flipped, and CPUID isn't supported.
-    cmp eax, ecx
-    je .no_cpuid
-    ret
-.no_cpuid:
-    mov al, "1"
-    jmp error
-
-check_long_mode:
-    ; test if extended processor info in available
-    mov eax, 0x80000000    ; implicit argument for cpuid
-    cpuid                  ; get highest supported argument
-    cmp eax, 0x80000001    ; it needs to be at least 0x80000001
-    jb .no_long_mode       ; if it's less, the CPU is too old for long mode
-
-    ; use extended info to test if long mode is available
-    mov eax, 0x80000001    ; argument for extended processor info
-    cpuid                  ; returns various feature bits in ecx and edx
-    test edx, 1 << 29      ; test if the LM-bit is set in the D-register
-    jz .no_long_mode       ; If it's not set, there is no long mode
-    ret
-.no_long_mode:
-    mov al, "2"
-    jmp error
-
-; Prints `ERR: ` and the given error code to screen and hangs.
-; parameter: error code (in ascii) in al
-error:
-    mov dword [0xb8000], 0x4f524f45
-    mov dword [0xb8004], 0x4f3a4f52
-    mov dword [0xb8008], 0x4f204f20
-    mov byte  [0xb800a], al
-    hlt
-
-set_up_page_tables:
-    ; map first P4 entry to P3 table
-    mov eax, p3_table
-    or eax, 0b11 ; present + writable
-    mov [p4_table], eax
-
-    ; map first P3 entry to P2 table
-    mov eax, p2_table
-    or eax, 0b11 ; present + writable
-    mov [p3_table], eax
-
-    ; map each P2 entry to a huge 2MiB page
-    mov ecx, 0         ; counter variable
-.map_p2_table:
-    ; map ecx-th P2 entry to a huge page that starts at address 2MiB*ecx
-    mov eax, 0x200000  ; 2MiB
-    mul ecx            ; start address of ecx-th page
-    or eax, 0b10000011 ; present + writable + huge
-    mov [p2_table + ecx * 8], eax ; map ecx-th entry
-
-    inc ecx            ; increase counter
-    cmp ecx, 512       ; if counter == 512, the whole P2 table is mapped
-    jne .map_p2_table  ; else map the next entry
-
-    ret
-
-enable_paging:
-    ; load P4 to cr3 register (cpu uses this to access the P4 table)
-    mov eax, p4_table
-    mov cr3, eax
-
-    ; enable PAE-flag in cr4 (Physical Address Extension)
-    mov eax, cr4
-    or eax, 1 << 5
-    mov cr4, eax
-
-    ; set the long mode bit in the EFER MSR (model specific register)
-    mov ecx, 0xC0000080
-    rdmsr
-    or eax, 1 << 8
-    wrmsr
-
-    ; enable paging in the cr0 register
-    mov eax, cr0
-    or eax, 1 << 31
-    mov cr0, eax
-
-    ret
-
-section .bss
-align 4096
-p4_table:
-    resb 4096
-p3_table:
-    resb 4096
-p2_table:
-    resb 4096
-stack_bottom:
-    resb 64
-stack_top:
-
-section .rodata
-gdt64:
-    dq 0 ; zero entry
-.code: equ $ - gdt64
-    dq (1<<43) | (1<<44) | (1<<47) | (1<<53) ; code segment
-.pointer:
-    dw $ - gdt64 - 1
-    dq gdt64