fasm-putchar-virittelyy

src/font.asm

@@ -0,0 +1,38 @@
+;; Thank you Terminus for letting us use this font under SIL licence
+kfont:
+; controlchars
+times 31 db 0x00000000000000000000000000000000
+; space
+db 11000000b
+db 10000000b
+db 00000000b
+db 00000000b
+db 00000000b
+db 00000001b
+db 00000001b
+db 00000001b
+db 00000001b
+db 00000000b
+db 00000000b
+db 00000000b
+db 00000000b
+db 00000000b
+db 00000001b
+db 00000011b
+; !
+db 00000000b
+db 00000000b
+db 00011000b
+db 00011000b
+db 00011000b
+db 00011000b
+db 00011000b
+db 00011000b
+db 00011000b
+db 00000000b
+db 00011000b
+db 00011000b
+db 00000000b
+db 00000000b
+db 00000000b
+db 00000000b

src/framebuffer.asm

@@ -42,3 +42,60 @@ putpixel:
 
 	pop ebp
 	ret
+
+; char, x, y
+putchar:
+	push ebp
+	mov ebp, esp
+	push eax
+	push ebx
+	push ecx
+	push edx
+
+	; skip non printable
+	mov eax, [ebp+8] ;char
+	cmp eax, 0x20
+	jl .unprintable
+	cmp eax, 0x7e
+	jg .unprintable
+
+	mov ecx, 16
+	mul ecx
+	mov esi, [kfont+eax]
+
+	mov ebx, [ebp+12] ;x
+	mov edx, [ebp+16] ;y
+
+	cld
+	xor eax, eax
+.loop:
+	lodsb	; load font row to al
+	mov ah, 0
+.loop2:
+	shl al
+	jnc .blankpix
+	; draw a pixel
+	push 0xff
+	push edx ;x
+	push ecx ;y
+.blankpix:
+	inc ah
+	cmp ah, 8
+	je .loop
+
+
+.done:
+	pop edx
+	pop ecx
+	pop ebx
+	pop eax
+	pop ebp
+	ret
+.unprintable:
+	push .unprintablemsg
+	call serialwrite
+	add esp, 4
+	jmp .done
+.unprintablemsg: db 10,"Err: Unprintable char not handled!", 0
+
+include "src/font.asm"

src/start32.asm

@@ -133,6 +133,12 @@ rOSkalogodraw:
 	jne .loop
 .done:
 
+push byte 0x21
+push byte 0x21
+push byte 0x21
+call putchar
+add esp, 3*4
+
 	jmp hang
 
 hang: