fix(kernel): cga scrolling

kernel/Makefile

@@ -18,6 +18,7 @@ SRCS	= kernel.asm \
 			dev/at/cga.inc \
 			dev/at/kbd.inc \
 			dev/at/floppy.inc \
+			dev/dev.inc \
 			fs/fat.inc \
 			fs/stpdfs.inc \
 			fs/xv6fs.inc \

kernel/dev/at/cga.inc

@@ -87,7 +87,7 @@ cga_putc:
 	xor ah, ah
 	mov cx, [ebp-0x2]
 	add cx, ax
-	jmp .end
+	jmp .next
 @@:
 	mov edx, CGA_MEMORY
 	xor ecx, ecx
@@ -99,6 +99,7 @@ cga_putc:
 	mov cx, [ebp-0x2]
 	inc cx
 
+.next:
 	mov ax, cx
 	mov dl, CGA_COLUMNS
 	div dl
@@ -110,20 +111,20 @@ cga_putc:
 	; scroll up
 	push esi
 	push edi
-	mov ecx, CGA_COLUMNS*(CGA_LINES-1)
+	mov ecx, CGA_COLUMNS*(CGA_LINES)*2
 	mov edi, CGA_MEMORY
 	mov esi, CGA_MEMORY+80*2
 	rep movsw
 
 	mov ecx, CGA_COLUMNS
 	xor ax, ax
-	mov edi, CGA_MEMORY+(CGA_COLUMNS*(CGA_LINES-1)*2)
+	mov edi, CGA_MEMORY+(CGA_COLUMNS*(CGA_LINES)*2)
 	rep stosw
 
 	pop esi
 	pop edi
 
-	mov cx, CGA_COLUMNS*(CGA_LINES-1)
+	mov cx, CGA_COLUMNS*(CGA_LINES)
 .end:
 	mov ax, cx
 	call cga_setpos

kernel/dev/at/cmos.inc

@@ -57,4 +57,8 @@
 CMOS_COMMAND = 0x70
 CMOS_DATA    = 0x71
 
+CMOS_REG_SECOND = 0x00
+CMOS_REG_MINUTE = 0x02
+CMOS_REG_HOUR   = 0x04
+
 CMOS_FLOPPY_TYPE = 0x10

kernel/dev/at/floppy.inc

@@ -37,5 +37,10 @@ floppy_probe:
 floppy_irq:
 	iret
 
+floppy_device:
+	dd floppy_probe
+	dd 0
+	dd 0
+
 szMsgFloppy0Found db "floppy0: Found", 0
 szMsgFloppy1Found db "floppy1: Found", 0

kernel/dev/console.inc

@@ -21,4 +21,9 @@ console_read:
 console_init:
 	ret
 
+console_device:
+	dd console_probe
+	dd console_write
+	dd console_write
+
 uConsoleLock dd 0

kernel/dev/dev.inc

@@ -1,10 +1,27 @@
 	;; File: dev.inc
 
 struc Device {
+	.probe dd ?
 	.write dd ?
 	.read  dd ?
-	.probe dd ?
 }
+DEFN Device
+
+aDevices:
+	dd console_device
+	dd floppy_device
+.end:
 
 dev_init:
+	mov ecx, aDevices
+@@:
+	mov eax, [ecx]
+	mov eax, [eax + Device.probe]
+	push ecx
+	call eax
+	pop ecx
+	add ecx, 4
+	cmp ecx, aDevices.end
+	jb @b
+
 	ret

kernel/fs/fat.inc

@@ -71,3 +71,27 @@ fatfs_init:
 	mov eax, vfs_fatfs
 	call vfs_register
 	ret
+
+fatfs_mount:
+	ret
+
+fatfs_start:
+	ret
+
+fatfs_unmount:
+	ret
+
+fatfs_root:
+	ret
+
+fatfs_statvfs:
+	ret
+
+fatfs_loadvnode:
+	ret
+
+fatfs_newvnode:
+	ret
+
+fatfs_mountroot:
+	ret

kernel/kernel.asm

@@ -65,6 +65,8 @@ kmain:
 
 	call pit_init
 
+	call dev_init
+
 	call vfs_init
 
 	mov eax, SYSCALL_EXIT
@@ -73,8 +75,6 @@ kmain:
 	;mov al, 'X'
 	;call cga_putc
 
-	call floppy_probe
-
 .halt:
 	hlt
 	jmp $
@@ -91,6 +91,7 @@ kmain:
 	include 'dev/at/floppy.inc'
 	include 'klog.inc'
 	include 'dev/console.inc'
+	include 'dev/dev.inc'
 	include 'mm/mm.inc'
 	include 'lock.inc'
 	include 'gdt.inc'

kernel/klog.inc

@@ -1,13 +1,6 @@
 	;; File: klog.inc
 	;; Kernel logging utilities
 
-CMOS_COMMAND = 0x70
-CMOS_DATA    = 0x71
-
-CMOS_REG_SECOND = 0x00
-CMOS_REG_MINUTE = 0x02
-CMOS_REG_HOUR   = 0x04
-
 COM1 = 0x3F8
 
 klog_kputc: