Espresso 0.0.1e

2025-07-04 14:23:29 -05:00
parent dd11e15c3b
commit dbaee2c881
17 changed files with 215 additions and 20 deletions
--- a/arch/x86/vga_fonts.asm
+++ b/arch/x86/vga_fonts.asm
@ -0,0 +1,86 @@
+
+global _get_fonts_asm
+
+_get_fonts_asm:
+
+; NOTE: this code is taken from https://wiki.osdev.org/VGA_Fonts
+
+    ;in: edi=4k buffer
+	;out: buffer filled with font
+	;clear even/odd mode
+	mov			dx, 03ceh
+	mov			ax, 5
+	out			dx, ax
+	;map VGA memory to 0A0000h
+	mov			ax, 0406h
+	out			dx, ax
+	;set bitplane 2
+	mov			dx, 03c4h
+	mov			ax, 0402h
+	out			dx, ax
+	;clear even/odd mode (the other way, don't ask why)
+	mov			ax, 0604h
+	out			dx, ax
+	;copy charmap
+	mov			esi, 0A0000h
+	mov			ecx, 256
+	;copy 16 bytes to bitmap
+@@:		movsd
+	movsd
+	movsd
+	movsd
+	;skip another 16 bytes
+	add			esi, 16
+	loop			@@
+	;restore VGA state to normal operation
+	mov			ax, 0302h
+	out			dx, ax
+	mov			ax, 0204h
+	out			dx, ax
+	mov			dx, 03ceh
+	mov			ax, 1005h
+	out			dx, ax
+	mov			ax, 0E06h
+	out			dx, ax
+
+
+_set_fonts_asm:
+; NOTE: this code is taken from https://wiki.osdev.org/VGA_Fonts and edited a little bit
+
+    ;in: esi=4k buffer
+	;out: buffer filled with font
+	;clear even/odd mode
+	mov			dx, 03ceh
+	mov			ax, 5
+	out			dx, ax
+	;map VGA memory to 0A0000h
+	mov			ax, 0406h
+	out			dx, ax
+	;set bitplane 2
+	mov			dx, 03c4h
+	mov			ax, 0402h
+	out			dx, ax
+	;clear even/odd mode (the other way, don't ask why)
+	mov			ax, 0604h
+	out			dx, ax
+	;copy charmap
+	mov			edi, 0A0000h
+	mov			ecx, 256
+	;copy 16 bytes to bitmap
+m:		movsd
+	movsd
+	movsd
+	movsd
+	;skip another 16 bytes
+	add			esi, 16
+	loop			m
+	;restore VGA state to normal operation
+	mov			ax, 0302h
+	out			dx, ax
+	mov			ax, 0204h
+	out			dx, ax
+	mov			dx, 03ceh
+	mov			ax, 1005h
+	out			dx, ax
+	mov			ax, 0E06h
+	out			dx, ax