Initial commit

1 files changed, 77 insertions, 0 deletions

diff --git a/kernel.asm b/kernel.asm
new file mode 100644
index 0000000..f613460
--- /dev/null
+++ b/kernel.asm
@@ -0,0 +1,77 @@
+bits 16
+
+jmp kmain
+
+%include "constants.asm"
+%include "string.asm"
+%include "disk.asm"
+%include "console.asm"
+%include "stdio.asm"
+
+
+kmain:
+	cli			; disable interrupts
+	mov ax, cs		; get code segment (i.e. far jump address in bootloader)
+	mov ds, ax		; set data segment
+	mov es, ax		; set extra segment
+	mov ax, 06000h
+	mov ss, ax		; set stack segment
+	mov sp, 0ffffh		; set stack pointer (~64k)
+	sti			; enable interrupts
+
+	mov [drive0], dx	; store bootloader's drive number
+
+	; reset general purpose registers
+	xor ax, ax
+	xor bx, bx
+	xor cx, cx
+	xor dx, dx
+	xor di, di
+	xor si, si
+	xor bp, bp
+
+
+	push banner
+	call puts
+
+.mainloop:
+	call kbd_read
+	call putc
+
+	jmp .mainloop
+
+	cli
+	jmp $
+
+
+panic:
+	; Hang system with supplied error message
+	push bp
+	mov bp, sp
+
+	push error_msg_panic	; i.e. 'PANIC:'
+	call puts
+	add sp, 2
+
+	push word [bp + 4]	; address of error string buffer
+	call puts		; print error
+	add sp, 2
+
+	cli			; disable interrupts
+	jmp $			; hang (no return)
+				; stack is dead
+
+
+; data
+kernel_address: dd 0	; format DS:ADDR
+banner: db "+========================+", CR, LF
+	db "| Welcome to MINOS 0.0.1 |", CR, LF
+	db "+========================+", CR, LF
+	db CR, LF, 0
+
+; Error messages
+error_msg_panic: db "PANIC: ", 0
+
+
+times 512 * 16 db 0
+dw 0xefbe