Cleaning up and adding page fault handler

[tpg/acess2.git] / Kernel / arch / x86_64 / start32.asm

diff --git a/Kernel/arch/x86_64/start32.asm b/Kernel/arch/x86_64/start32.asm
index 248fa8d..4769ee4 100644 (file)
--- a/Kernel/arch/x86_64/start32.asm
+++ b/Kernel/arch/x86_64/start32.asm
@@ -5,21 +5,53 @@ KERNEL_BASE   equ     0xFFFF800000000000
 
 [section .multiboot]
 mboot:
-       MULTIBOOT_MAGIC equ     0x1BADB002
-       dd      MULTIBOOT_MAGIC
+       ; Multiboot macros to make a few lines later more readable
+       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)
+       
+       ; This is the GRUB Multiboot header. A boot signature
+       dd MULTIBOOT_HEADER_MAGIC
+       dd MULTIBOOT_HEADER_FLAGS
+       dd MULTIBOOT_CHECKSUM
+       [extern __load_addr]
+       [extern __bss_start]
+       [extern gKernelEnd]
+       ; a.out kludge
+       dd mboot        ; Location of Multiboot Header
+       dd __load_addr  ; Load address
+       dd __bss_start - KERNEL_BASE    ; End of .data
+       dd gKernelEnd - KERNEL_BASE     ; End of .bss (and kernel)
+       dd start - KERNEL_BASE  ; Entrypoint
 
 [extern start64]
 
 [section .text]
 [global start]
 start:
+       mov [gMultibootMagic - KERNEL_BASE], eax
+       mov [gMultibootPtr - KERNEL_BASE], ebx
+
+       ; Check for Long Mode support
+       mov eax, 0x80000000
+       cpuid
+       cmp eax, 0x80000001     ; Compare the A-register with 0x80000001.
+       mov eax, 0x80000001
+       cpuid
+    jb .not64bitCapable
+       test edx, 1<<29
+       jz .not64bitCapable
+
        ; Enable PAE
        mov eax, cr4
        or eax, 0x80|0x20
        mov cr4, eax
 
        ; Load PDP4
-       mov eax, gInitialPML4
+       mov eax, gInitialPML4 - KERNEL_BASE
        mov cr3, eax
 
        ; Enable long/compatability mode
@@ -34,48 +66,69 @@ start:
        mov cr0, eax
 
        ; Load GDT
-       lgdt [gGDTPtr]
-       mov ax, 0x10
-       mov ss, ax
-       mov ds, ax
-       mov es, ax
-       mov fs, ax
-       mov gs, ax
-
+       lgdt [gGDTPtr - KERNEL_BASE]
        jmp 0x08:start64 - KERNEL_BASE
 
+.not64bitCapable:
+       mov ah, 0x0F
+       mov edi, 0xB8000
+       mov esi, csNot64BitCapable - KERNEL_BASE
+
+.loop:
+       lodsb
+       test al, al
+       jz .hlt
+       stosw
+       jmp .loop
+       
+.hlt:
+       jmp .hlt
+
 [section .data]
+[global gGDT]
 gGDT:
        dd      0,0
-       dd      0x00000000, 0x00209800  ; 0x08: 64-bit Code
-       dd      0x00000000, 0x00009000  ; 0x10: 64-bit Data
-       dd      0x00000000, 0x00209800  ; 0x18: 64-bit User Code
-       dd      0x00000000, 0x00209000  ; 0x20: 64-bit User Data
-       dd      0x00000000, 0x00209800  ; 0x38: 32-bit User Code
-       dd      0x00000000, 0x00209000  ; 0x30: 32-bit User Data
+       dd      0x00000000, 0x00209A00  ; 0x08: 64-bit Code
+       dd      0x00000000, 0x00009200  ; 0x10: 64-bit Data
+       dd      0x00000000, 0x0020FA00  ; 0x18: 64-bit User Code
+       dd      0x00000000, 0x0000F200  ; 0x20: 64-bit User Data
+       dd      0x00000000, 0x0040FA00  ; 0x38: 32-bit User Code
+       dd      0x00000000, 0x0040F200  ; 0x30: 32-bit User Data
        times MAX_CPUS  dd      0, 0, 0, 0      ; 0x38+16*n: TSS 0
 gGDTPtr:
        dw      $-gGDT-1
-       dd      gGDT
+       dd      gGDT-KERNEL_BASE
+       dd      0
+[global gMultibootPtr]
+[global gMultibootMagic]
+gMultibootMagic:
+       dd      0
+gMultibootPtr:
        dd      0
 
 [section .padata]
+[global gInitialPML4]
 gInitialPML4:  ; Covers 256 TiB (Full 48-bit Virtual Address Space)
        dd      gInitialPDP - KERNEL_BASE + 3, 0        ; Identity Map Low 4Mb
        times 256-1 dq  0
        dd      gInitialPDP - KERNEL_BASE + 3, 0        ; Map Low 4Mb to kernel base
-       times 256-1 dq 0
+       times 256-1-4 dq 0
+       dd      gInitialPML4 - KERNEL_BASE + 3, 0       ; Fractal Mapping
+       dq      0
+       dq      0
+       dq      0
 
 gInitialPDP:   ; Covers 512 GiB
        dd      gInitialPD - KERNEL_BASE + 3, 0
-       times 511 dq    0
+       times 511       dq      0
 
 gInitialPD:    ; Covers 1 GiB
        dd      gInitialPT1 - KERNEL_BASE + 3, 0
        dd      gInitialPT2 - KERNEL_BASE + 3, 0
+       times 510       dq      0
 
 gInitialPT1:   ; Covers 2 MiB
-       %assign i 1
+       %assign i 0
        %rep 512
        dq      i*4096+3
        %assign i i+1
@@ -88,3 +141,6 @@ gInitialPT2: ; 2 MiB
        %endrep
 
 
+[section .rodata]
+csNot64BitCapable:
+       db "Not 64-bit Capable",0