Initial Commit

2023-12-21 22:13:56 +01:00
commit a346d66879
14 changed files with 340 additions and 0 deletions
@@ -0,0 +1,60 @@
+[org 0x7c00]
+[bits 16]
+[global start]
+
+start:
+    ; Setup
+    xor ax, ax
+    mov es, ax
+    mov ds, ax
+    mov bp, 0x9000
+    mov sp, bp
+
+    ; Read filetable from disk
+    mov bx, FILETAB_LOC ; Filetable location in memory
+    mov es, bx
+    xor bx, bx
+
+    mov ah, 2           ; Read from disk
+    mov al, 1           ; Read 1 sector
+    mov ch, 0           ; Cylinder
+    mov dh, 0           ; Head
+    mov cl, 2           ; Sector
+    int 0x13            ; INT 0x13 - Disk operations
+
+    jc readFail         ; CF will be set if the read fails
+
+    ; Read filetable from disk
+    mov bx, KERNEL_LOC ; Filetable location in memory
+    mov es, bx
+    xor bx, bx
+
+    mov ah, 2           ; Read from disk
+    mov al, 2           ; Read 2 sectors
+    mov ch, 0           ; Cylinder
+    mov dh, 0           ; Head
+    mov cl, 3           ; Sector
+    int 0x13            ; INT 0x13 - Disk operations
+
+    jc readFail         ; CF will be set if the read fails
+
+    ; Setup segmentation
+    mov ax, KERNEL_LOC
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+    mov ss, ax
+
+    ; Far jump to the kernel
+    jmp KERNEL_LOC:0x0
+
+readFail:
+    cli
+    hlt
+
+FILETAB_LOC equ 0x1000
+KERNEL_LOC equ 0x2000
+
+times 510-($-$$) db 0
+dw 0xaa55