Bootloader v0.1.0.0 - Support for some more BIOS versions

bootloader.nasm

@@ -1,6 +1,19 @@
+ORG 0x7C00
 BITS 16
-;http://www.ousob.com/ng/bios/ng1223.php
-start:
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; Bootloader for SingOS
+; version 0.1.0.0
+;
+; Please edit the version number if any changes is made, the last number
+; represent the build number. 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+    xor ax, ax
+    mov ds, ax
+    mov es, ax
+    mov ss, ax
+
+    ; initialize stack
     ; Set up 4K stack after this bootloader
     ; [Remember: Effective Address = Segment*16 + Offset]
     mov ax, 0x7C0   ; Set 'ax' equal to the location of this bootloader divided by 16
@@ -8,12 +21,18 @@ start:
     mov ss, ax      ; Set 'ss' to this location (the beginning of our stack region)
     mov sp, 8192    ; Set 'ss:sp' to the top of our 8K stack
 
-    ; Set data segment to where we're loaded so we can implicitly access all 64K from here
-    mov ax, 0x7C0   ; Set 'ax' equal to the location of this bootloader divided by 16
-    mov ds, ax      ; Set 'ds' to the this location
+    jmp long 0x0000:start
+    nop
+
+start:
+    nop
+    nop
+    nop
+    nop
+    nop
+    nop
 
     mov [disk_identifier], dl
-	; Print our message and stop execution
 	mov si, message ; Put address of the null-terminated string to output into 'si'
 	call print      ; Call our string-printing routine
 	mov si, enter_debug_mode
@@ -52,32 +71,28 @@ start:
     mov dl, [disk_identifier] ;0x0    ;Drive number
     mov bx, 0x500     ;Offset into section
     int 0x13         ;Low level disk services
-    ;mov [0x7000], es ; saving retult of read
-;   
-    ;Debug dump of loaded memory
-    ;mov si, 500
-    ;mov cx, 512   
-    ;call b_dumpmem
 
     jnc notcarry
     mov si, error_str
     call print
     jmp endcarrycheck
-;      
+
     notcarry:
     mov si, success_str
     call print
     call printCRLF
     call printCRLF
+    mov ax, cs
+    call dumpax
+    mov ax, start
+    call dumpax
+    call printCRLF
     
-    ; xor ax, ax
-    ; mov al, [disk_identifier]
-    ; call dumpax
     mov dl, [disk_identifier]
     
     mov ax, 0x50
     mov ds, ax
-    jmp 0x50:0x00 ; 0x500
+    jmp 0x50:0x00   ; Jump to the kernel 
 
 endcarrycheck:  
     cli             ; Clear the Interrupt Flag (disable external interrupts)
@@ -91,7 +106,7 @@ debug_mode:
 
     .welcome_debug db 'This is debug mode', 0
 data:
-	message db 'Bootloader for SingOS! v0.0.3',13,10,0
+	message db 'Bootloader for SingOS! v0.1.0.0',13,10,0
     enter_debug_mode db 'Press d to enter bootloader debug mode',13,10,0
     enter_system_check db 'Performing system check:',13,10,0
     sys_check_ok db 'System check ok', 13, 10, 0
@@ -122,64 +137,64 @@ dumpax:
 	popa			; restore registers
 	ret
 
-dumpax10: ; Prints ax as 16-bit decimal number
-	pusha
+; dumpax10: ; Prints ax as 16-bit decimal number
+; 	pusha
 
-	mov bx, 10	; Divisor
+; 	mov bx, 10	; Divisor
 
-	mov cx, 5	; Loop 5 times
-.loop1: ; finds digits and pushes them to stack
-	xor dx, dx
-	div bx
-	add dl, '0'
-	push dx
-	loop .loop1
+; 	mov cx, 5	; Loop 5 times
+; .loop1: ; finds digits and pushes them to stack
+; 	xor dx, dx
+; 	div bx
+; 	add dl, '0'
+; 	push dx
+; 	loop .loop1
 
 	
-	mov ah, 0xE
-	mov cx, 5	; Loop 5 times
-	mov bl, '0'
-
-.loop2: ; Pops from stack until it hits a non-'0' value. It then jumps to nonzero_nopop to print it.
-	pop dx
-	mov al, dl
-	cmp al, bl
-	jne .nonzero_nopop
-	loop .loop2
-
-.nonzero_loop: ; Pops values from the stack and prints them.
-	pop dx
-	mov al, dl
-.nonzero_nopop: ; Part of the loop that prints the value. Jump to here to print without popping on first iteration.
-	int 0x10
-	loop .nonzero_loop
-
-	popa
-	ret
-
-dumpax10_rev: ; Prints ax as 16-bit decimal number in reverse
-	pusha
-
-	mov cx, 10	; Divisor
-.loop:
-	xor dx, dx	; zero dx
-	div cx		; Divide dx:ax by 10 -> quotient in ax, remainder in dx
+; 	mov ah, 0xE
+; 	mov cx, 5	; Loop 5 times
+; 	mov bl, '0'
+
+; .loop2: ; Pops from stack until it hits a non-'0' value. It then jumps to nonzero_nopop to print it.
+; 	pop dx
+; 	mov al, dl
+; 	cmp al, bl
+; 	jne .nonzero_nopop
+; 	loop .loop2
+
+; .nonzero_loop: ; Pops values from the stack and prints them.
+; 	pop dx
+; 	mov al, dl
+; .nonzero_nopop: ; Part of the loop that prints the value. Jump to here to print without popping on first iteration.
+; 	int 0x10
+; 	loop .nonzero_loop
+
+; 	popa
+; 	ret
+
+; dumpax10_rev: ; Prints ax as 16-bit decimal number in reverse
+; 	pusha
+
+; 	mov cx, 10	; Divisor
+; .loop:
+; 	xor dx, dx	; zero dx
+; 	div cx		; Divide dx:ax by 10 -> quotient in ax, remainder in dx
 	
-	mov bx, ax	; save quotient in bx
+; 	mov bx, ax	; save quotient in bx
 
-	mov al, dl	; put remainder in al
-	add al, '0'	; Make ASCII
+; 	mov al, dl	; put remainder in al
+; 	add al, '0'	; Make ASCII
 
-	mov ah, 0xE	; Set teletype output
-	int 0x10	; BIOS: write one char
+; 	mov ah, 0xE	; Set teletype output
+; 	int 0x10	; BIOS: write one char
 	
-	mov ax, bx
-	;test ax, ax
-        cmp ax, 0
-	jnz .loop
+; 	mov ax, bx
+; 	;test ax, ax
+;         cmp ax, 0
+; 	jnz .loop
 
-	popa
-	ret
+; 	popa
+; 	ret
 
 printCRLF:
     mov ah, 0xE

kernel.nasm

@@ -6,7 +6,7 @@ start_sing:
     ; VSFS is loaded:
     mov [global_disk_identifier], dl    ; saving disk_identifier, this is the number the disk that we are booting from. 
                                         ; This number is set by the bios
-jmp sing_ready
+jmp sing_loaded
 %include "mem_lib/mem_lib.nasm"
 %include "lib/os_lib.nasm"
 %include "lib/string.nasm"
@@ -16,14 +16,15 @@ jmp sing_ready
 %include "vsfs/vsfs.nasm"
 %include "CLI/CLI.nasm"
 
-sing_ready:     ; SingOS is ready for the user: 
+sing_loaded:     ; SingOS is ready for the user: 
+
     mov ax, 0x8fc0
     mov ss, ax      ; Set 'ss' to this location (the beginning of our stack region)
     mov sp, 0xffff    ; Set 'ss:sp' to the top of our 8K stack
     mov bp, sp
 
-    call os_clear_screen
-
+sing_ready:     ; SingOS is ready for the user: 
+    ;call os_clear_screen
     mov si, welcome ; Put address of the null-terminated string to output into 'si'
     call print      ; Call our string-printing routine
 
@@ -45,9 +46,6 @@ sing_ready:     ; SingOS is ready for the user:
 
     call print_help_message
 
-    ; call dump_status_flags
-    ; call printCRLF
-
     mov si, command_line
     call print
     jmp terminal
@@ -76,6 +74,7 @@ wait_for_key:
     cmp cx, 0x0e08  ; backspace key
     ;je .backspace_handler
     jne .dont_backspace
+
     call CLI_DELETE
     popa
     ret
@@ -97,7 +96,7 @@ wait_for_key:
     ;mov ax, [.tmp_buf]
     ;mov [bx], ax
     .return_enter:
-    mov ax, [.tmp_buf]
+    ;mov ax, [.tmp_buf]
     popa ; But restore all other regs
     ret
 

lib/debug_tools.nasm

@@ -58,9 +58,12 @@
 BITS 16
 
 dumpmem_hardcoded_args:
+    push ds ; THIS IS ALSO HACKY
     mov si, sp
-    mov si, [si]
-    mov cx, 400
+    mov ax, ss
+    mov ds, ax
+    ;mov si, [si]
+    mov cx, 256
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 dumpmem:
 ; Dumps memory
@@ -81,6 +84,7 @@ dumpmem:
     .end:
 
     popa
+    pop ds ; THIS IS ONLY FOR DEBUG - REMOVE REMOVE REMOVE
     ret
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;