idk what i added

data/README.md

@@ -0,0 +1,9 @@
+Kernel written in Assmebly
+I'm using a modified JazzOS Bootloader
+
+Commands:
+CAT
+HELP
+CLEAR
+REBOOT
+PONG

data/var.cws

@@ -0,0 +1 @@
+x = 5

source/kernel/data.asm

@@ -0,0 +1,58 @@
+; Define Fat12 header
+bdb_oem:                    db 'MSWIN4.1' ; ignore
+bdb_bytes_per_sector:       dw 200h ; = 512d
+bdb_sectors_per_cluster:    db 01h ; sector = cluster
+bdb_reserved_sectors:       dw 01h
+bdb_fat_count:              db 02h  ; We've got a fat1 and fat2
+bdb_dir_entries_count:      dw 0E0h ; Maximum number of root directory entries
+bdb_total_sectors:          dw 0B40h ; = 2880d
+bdb_media_descriptor_type:  db 0F0h ; ignore
+bdb_sectors_per_fat:        dw 09h
+bdb_sectors_per_track:      dw 12h ; = 18d
+bdb_number_of_heads:        dw 02h ; top and bottom of the floppy disk
+bdb_hidden_sectors:         dd 0 ; ignore
+bdb_large_sector_count:     dd 0 ; total sector count for fat32 (0 for fat12 or fat16)
+
+; extended boot record
+ebr_drive_number:           db 0 ; ignore
+                            db 0 ; ignore
+ebr_signature:              db 29h ; boot signature, indicates that the next three fields are present (0x29)
+ebr_volume_id:              db 12h, 34h, 56h, 78h ; unique id for volume tracking
+ebr_volume_label:           db 'CRAWOS0.0.6' ; must be 11 bytes
+ebr_system_id:              db 'FAT12   ' ; must be 8 bytes
+
+
+fat12_file_name: db '           ' ; 11 free bytes to store a filename in
+boot_message: db 'OK] Kernel successfully loaded!\n\n', 0
+user_input: times 20 db 0
+prompt_length: db 20
+prompt: db 'sh > ', 0
+help_string: db 'HELP', 0
+clear_string: db 'CLEAR', 0
+reboot_string: db 'REBOOT', 0
+pong_string: db 'PONG', 0
+cat_string: db 'CAT', 0
+ls_string: db 'LS', 0
+help_text: db 'This is for Cowards:\n"LS" to list the directory,\n"CAT" to output the contents of a file,\n"HELP" for this helpful text,\n"CLEAR" to clear the screen,\n"REBOOT" or esc to reboot\n', 0
+command_result_text: db 'You typed: ', 0
+unknown_command: db 'Error: Unkown Command..\n ', 0
+
+; Disk operations
+disk_read_fail: db 'Error: Could not read disk\n', 0
+file_not_found: db 'File not found\n', 0
+too_long_filename: db 'Filename too long for Fat12\n', 0
+file_found: db 'File found\n', 0
+loading_root: db 'Loading root diretory\n', 0
+read_only: db 'Read Only', 0 ; 1
+hidden:    db '  Hidden ', 0 ; 2
+system:    db '  System ', 0 ; 4
+volume:    db '  Volume ', 0 ; 8
+directory: db 'Directory', 0 ; 10
+archive:   db ' Archive ', 0 ; 20
+file_name_length: db 0
+file_cluster: dw 0
+file_length: dd 0
+read_write_flag: db 02
+empty_byte: db 0
+empty_word: dw 0
+empty_dword: dd 0

source/kernel/features/cli.asm

@@ -45,6 +45,20 @@ os_read_cli:
 	cmp cl, 1
 	je power_reboot
 
+	; Cat
+	mov si, user_input
+	mov di, cat_string
+	call os_compare_strings
+	cmp cl, 1
+	je cat
+
+    ; LS
+	mov si, user_input
+	mov di, ls_string
+	call os_compare_strings
+	cmp cl, 1
+	je ls
+	
 	; Pong
 	mov si, user_input
 	mov di, pong_string
@@ -78,16 +92,9 @@ pong:
 	call game_pong
 	call os_read_cli.finish
 
-section .data
+cat:
-    welcome_text db 'Welcome to CrawOS, the Cwick, Real and AWsome Operating System\n', 0
+   call util_cat
-	user_input times 20 db 0
+   call os_read_cli.finish
-	prompt_length db 20
+ls:
-	prompt db 'CrawOS sh> ', 0
+   call util_ls
-	help_string db 'HELP', 0
+   call os_read_cli.finish
-	clear_string db 'CLEAR', 0
-	reboot_string db 'REBOOT', 0
-	cat_string db 'CAT', 0
-	pong_string db 'PONG', 0
-	help_text db 'This is for Cowards:\n"HELP" for this helpful text,\n"CLEAR" to clear the screen,\n"REBOOT" or esc to reboot\n', 0
-	command_result_text db 'You typed: ', 0
-	unknown_command db 'Error: Unkown Command.. \n', 0

source/kernel/features/disk.asm

@@ -14,7 +14,7 @@ disk_load_root:
    pusha
    mov ax, 19 ; First sector of root entry
    call math_lba_to_chs ; Assigns ch, cl and dh the correct values
-   xor ax,ax
+   xor ax,ax ; clear ax so I can use it on next line
    mov dl, [ebr_drive_number]  ; Drive number
    mov ah, 02h  ; BIOS ah code for read disk sectors to memory
    mov al, 0Ch  ; Root directory has 12 sectors
@@ -53,28 +53,34 @@ disk_load_root:
 ; ---------------------------------------------
 
 ; Reads a certain number of sectors into memory
-; int 13h/ah = 02h read disk sectors into memory
+; IN
+; ax = LBA
+; es:bx = area to read to/write from
+; [read_write_flag] = 02 or 03 for read or write
+; dl = ebr drive number
+; int 13h/ah = 02h/03h read/write disk sectors into memory
 ; al = number of sectors to read
+; ah = read/write 02=read, 03=write IMPORTANT
 ; ch = cylinder number
 ; cl = sector number
 ; dh = head number
 ; dl = drive number
 ; es:bx = points to data buffer
-disk_read:
+disk_read_or_write:
    push ax
    push bx
    push cx
    push dx
    push di
 
-
    ; cl = sector
    ; ch = cylinder
    ; dh = head
    ; dl = drive
    call math_lba_to_chs  ; Get the chs address
 
-   mov ah, 02h  ; BIOS ah code for read disk sectors to memory
+   mov ah, [read_write_flag]
+   mov al, 1
 
    ; repeat drive read 3 times (incase of random error)
    mov di, 3 ; counter
@@ -122,10 +128,55 @@ disk_read:
    pop ax
    ret
 
-; -------------------------------------
 
+; -------------------------------------
+; CLEAR DATA
+; Uses the metadata buffer to determine the file size in the data buffer and clears it.
+disk_clear_file_buffer:
+	pusha
+
+	mov si, metadata_buffer
+	mov cx, [si+28] ; MOve the filelength into the ax
+	shr cx, 1 ; Divide by 4 because we'll write over using double words
+	mov si, empty_word
+	lodsb ; Load the empty dword
+	mov di, file_buffer
+	.loop:
+		stosb
+		dec cx
+		cmp cx, 0
+		jbe .loop
+	.finish:
+		popa
+		ret
+disk_clear_output_buffer:
+	pusha
+	mov cx, 0x7f0 ; Length of the output buffer
+	mov si, empty_word
+	lodsb ; Load the empty word into ax
+	mov di, output_buffer
+	.loop:
+		stosb ; Store empty dword in di
+		dec cx
+		cmp cx, 0
+		ja .loop
+	.finish:
+		popa
+		ret
+
+; -------------------------------------
+; IN
+; si: filename
+
+; OUT
+; data_buffer: file contents
+; TODO use predefined data for calculations
 disk_load_file:
    pusha
+   call os_string_length ; cl = string length
+   cmp cl, 11
+   ja .filename_too_long
+
    mov di, fat12_file_name
    call os_format_fat_filename
 
@@ -134,7 +185,7 @@ disk_load_file:
    xor bx,bx
 .search_root:
    mov di, fat12_file_name ; Move the name of the kernel into di
-   mov cx, 11 ; length of 'KERNEL  BIN'
+   mov cx, 11 ; length of filenames in fat12
    push si ; Preserve si
    repe cmpsb ; Repeat a comparison of bytes between file name and current bytes until it finds a match
    pop si ; Retrieve si
@@ -147,29 +198,179 @@ disk_load_file:
 
    jmp .file_not_found ; If the last dir has been searched, then there is no kernel
 .found_file:
+   call disk_clear_file_buffer
+   mov di, metadata_buffer
+   mov cx, 32
+.write_metadata:
+   ; Write data to metadata buffer
+   lodsb
+   stosb
+   sub cx, 1
+   cmp cx, 0
+   jne .write_metadata
+.read_kernel:
+   sub si, 32
+   mov ax, [si+28]   ; File length
+   mov [file_length], ax
    mov ax, [si+26]   ; ax is now a pointer to the pointer to the file relative to the data segments :D
-   add ax, 20h
+   add ax, 1Fh
    mov [file_cluster], ax
    ; Setup registers for disk read
-   mov bx, data_buffer
+   mov si, file_buffer
+   mov bx, si
    mov dl, [ebr_drive_number]
 
-   call disk_read ; Load file from disk into memory
+   mov ch, 02h
+   mov [read_write_flag], ch ; READ
+   call disk_read_or_write ; Load file from disk into memory
    jmp .done
 .file_not_found:
    mov si, file_not_found
    call os_print_string
    jmp .done
+.filename_too_long:
+   mov si, too_long_filename
+   call os_print_string
+   jmp .done
 .done:
    popa
    ret
 
+; Write data to file
+; takes the contents in the data buffer for a fixed
+; number of characters definied by [file_length]
+; and write it to the file that si points to
+; It also must edit the fat entry data
+disk_write_file:
+	pusha
+	; Check if file name is too long
+	call os_string_length ; cl = string length
+	cmp cl, 11
+	ja .filename_too_long
+	; Convert file name to a fat filename
+	mov di, fat12_file_name
+	call os_format_fat_filename
 
+	; Locate the file entry in memory
+	; Prepare values
+	mov si, root_buffer
+	xor bx,bx
+	.search_root:
+		mov di, fat12_file_name ; Move the name of the kernel into di
+		mov cx, 11 ; length of filenames in fat12
+		push si ; Preserve si
+		repe cmpsb ; Repeat a comparison of bytes between file name and current bytes until it finds a match
+		pop si ; Retrieve si
+		je .found_file
 
-section .data:
+		add si, 32 ; increment di to the next directory entry
-   disk_read_fail: db 'Error: Could not read disk\n', 0
+		inc bx
-   file_not_found: db 'File not found\n', 0
+		cmp bx, [bdb_dir_entries_count] ; Have we reached the number of directories that exist
-   file_found: db 'File found\n', 0
+		jl .search_root ; Repeat search
-   loading_root: db 'Loading root diretory\n', 0
+
-   file_cluster: dw 0
+		jmp .file_not_found ; If the last dir has been searched, then there is no kernel
-   fat12_file_name: db '           '
+	.found_file:
+	; Find where the file is on the disk
+		mov ax, [si+28]   ; File length entry
+		mov [file_length], ax
+		mov ax, [si+26]   ; ax is now a pointer to the pointer to the file relative to the data segments :D
+		add ax, 1Fh
+		mov [file_cluster], ax
+		; Setup registers for disk read
+		mov si, file_buffer
+		mov bx, si
+		mov dl, [ebr_drive_number]
+
+		mov ch, 03h
+		mov [read_write_flag], ch ; WRITE
+		call disk_read_or_write ; Load file from disk into memory
+		jmp .finish
+	; DI now points to a fat12 formatted file name
+
+	; Write to those sectors
+	; Update FAT entry
+	.file_not_found: ; TODO create a file if it's not found
+		mov si, file_not_found
+		call os_print_string
+		jmp .finish
+	.filename_too_long:
+		mov si, too_long_filename
+		call os_print_string
+		jmp .finish
+	.finish:
+		popa
+		ret
+
+; TODO support long file names
+; Store a list of the files in file_buffer
+; in a human readable format
+; OUT
+; output_buffer: the list (string)
+disk_list_contents:
+	pusha
+	mov si, root_buffer
+	mov di, output_buffer
+	.loop:
+		call string_unformat_fat_filename
+		mov cx, 000Ch
+		sub cx, [file_name_length]
+		add di, [file_name_length]
+		mov al, 20h
+		.space_loop:
+			stosb
+			dec cx
+			cmp cx, 0
+			jne .space_loop
+
+		.file_attribute:
+			add si, 11d
+			lodsb
+			push si
+
+			mov si, read_only
+			cmp al, 1h
+			je .add_string
+			mov si, hidden
+			cmp al, 2h
+			je .add_string
+			mov si, system
+			cmp al, 4h
+			je .add_string
+			mov si, volume
+			cmp al, 8h
+			je .add_string
+			mov si, directory
+			cmp al, 10h
+			je .add_string
+			mov si, archive
+			cmp al, 20h
+			je .add_string
+
+		.after_file_attributes:
+		pop si
+
+		mov al, 0Ah
+		stosb
+
+		add si, 20d
+		lodsb ; +1
+		dec si ; -1
+		cmp al, 0 ; You've come to the end of the root entries
+		je .finish
+		cmp al, 00E5h	; E5h is a marker that the Fat entry is available
+		je .finish
+		jmp .loop
+	.add_string:
+		.add_string_loop:
+			lodsb
+			cmp ax, 00h
+			je .after_file_attributes
+			stosb
+			jmp .add_string_loop
+	.finish:
+		mov cx, output_buffer
+		sub di, cx
+		mov [file_length], di
+		stosb
+		popa
+		ret

source/kernel/features/strings.asm

@@ -62,8 +62,7 @@ os_format_fat_filename:
    pusha
    call os_upper_case
    call os_string_length ; Stores the length of the string in cl
-   mov bl, 11
+   xor ch,ch ; Clear ch to reset it to 0
-   sub bl, cl ; 11 - string_length
    .character_loop:
 	  lodsb
 	  cmp al, 0
@@ -71,10 +70,18 @@ os_format_fat_filename:
 	  cmp al, 2Eh ; 2Eh
 	  je .add_spaces ; This will end up back at .character_loop
 	  stosb
+	  inc ch
 	  jmp .character_loop
 
    .add_spaces: ; Add the number of spaces as bl holds
 	  mov al, ' ' ; 20h = space
+
+	  ; Work out the number of spaces in between
+	  ; the name and extension.
+	  ; 8 - name_length(ch)
+	  xor bl, bl
+	  sub bl, ch
+	  add bl, 7
 	  .spaces_loop:
 		 stosb
 		 cmp bl, 0
@@ -85,6 +92,58 @@ os_format_fat_filename:
 	  popa
 	  ret
 
+; Does the inverse of the previous
+; Converts a fat filename back to human readable
+; eg. 'KERNEL  BIN' -> 'KERNEL.BIN'
+; input: si points to fat filename (11 bytes)
+; output: 
+; di points to the unformatted filename
+; [file_name_length] stores the length of the filename
+string_unformat_fat_filename:
+	pusha
+
+	xor ax,ax
+	xor dx,dx
+	mov cx, 11 ; Counter
+	.name_loop:
+		lodsb
+		stosb
+		dec cx
+		inc dx
+		cmp cx, 3
+		jne .name_loop
+	push si
+	mov si, di
+	.space_loop:
+		dec si
+		lodsb
+		dec si
+		dec dx
+		cmp al, 20h ; Space
+		je .space_loop
+		jmp .insert_stop
+	.insert_stop:
+		mov di, si
+		inc di
+		inc dx
+		pop si
+		mov al, 2Eh
+		stosb
+	mov cx, 3
+	.extension_loop:
+		lodsb
+		stosb
+		dec cx
+		inc dx
+		cmp cx, 0
+		jne .extension_loop
+
+	.finish:
+		inc dx
+		mov [file_name_length], dx
+		popa
+		ret
+
 ; Convert a string to all upper/lower case
 ; INPUT: si pointing to a string
 ; OUPUT: the same string in memory will now be capitalised/decapitalised

source/kernel/features/text.asm

@@ -11,13 +11,70 @@ os_print_string:
 	lodsb				; Get char from si into al
 	cmp al, 0			; Compare al to 0
 	je .done			; If char is zero, end of string
+
+	cmp al, 0Ah			; When there's an NL or CR, do both, linux encodes files only with NL
+	je .new_line
+	cmp al, 0Dh
+	je .repeat
+
 	cmp al, 5Ch			; backslash
 	je .backslash
 
 	int 10h				; Otherwise, print it
 	jmp .repeat			; And move on to next char
 
-   .backslash: ; If there is a '\', do what it says, \n for newline, \t for tab etc
+   .new_line:
+	  mov al, 0Ah
+	  int 10h
+	  mov al, 0Dh
+	  int 10h
+	  jmp .repeat
+	.backslash:
+		call text_backslash
+		jmp .repeat
+.done:
+	popa
+	ret
+
+; This is similar to the previous, however it prints
+; raw output (including null) and prints the number
+; of character defined by cx
+; IN:
+; SI = pointer to start of string to be printed
+; CX = Length of string to print
+text_print_raw:
+	pusha
+	add cx, 1
+	mov ah, 0Eh
+	.repeat:
+		dec cx
+		cmp cx, 0
+		je .finish
+		lodsb
+		cmp al, 00h ; Print a space in place of a Null
+		je .space
+		cmp al, 0Ah	; When there's an NL or CR, do both, linux encodes files only with NL
+		je .new_line
+		cmp al, 0Dh
+		je .repeat
+		int 10h
+		jmp .repeat
+	.space:
+		mov al, 20h
+		int 10h
+		jmp .repeat
+	.new_line:
+		mov al, 0Ah
+		int 10h
+		mov al, 0Dh
+		int 10h
+		jmp .repeat
+	.finish:
+		popa
+		ret
+
+; NO PUSHING/POPPING!
+text_backslash: ; If there is a '\', do what it says, \n for newline, \t for tab etc
   lodsb
   dec si
   cmp al, 6Eh		; 'n'
@@ -26,7 +83,7 @@ os_print_string:
   je .tab
   cmp al, 5Ch ; '\'
   je .another_backslash
-	  jmp .repeat
+  ret
 	.newline:
 	  mov al, 0Ah ; new line
 	  int 10h
@@ -43,36 +100,7 @@ os_print_string:
 	  jmp .finish_backslash
 	.finish_backslash:
 	  inc si
-	  jmp .repeat
-.done:
-	popa
 	  ret
-
-; This is similar to the previous, however it prints
-; raw output (including null) and prints the number
-; of character defined by ax
-; IN:
-; SI = pointer to start of string to be printed
-; AX = Length of string to print
-text_raw_output:
-	pusha
-
-	mov di, ax
-
-	mov ah, 0Eh			; int 10h teletype function, we're telling the BIOS we will print something
-
-.repeat:
-	lodsb				; Get char from si into al
-	int 10h				; Otherwise, print it
-	dec di
-	cmp di, 00h
-	je .done
-	jne .repeat
-.done:
-	popa
-	ret
-
-
 ; --------------------------------------------
 
 os_print_newline:

source/kernel/features/time.asm

@@ -0,0 +1,8 @@
+time_get_time:
+	pusha
+
+	mov ah, 00h
+	int 1Ah
+
+	popa
+	ret

source/kernel/features/utils.asm

@@ -0,0 +1,28 @@
+util_cat:
+   pusha
+
+   call disk_clear_file_buffer
+   mov si, user_input
+   ; TODO make this more consistent to account for double spaces
+   add si, 4   ; Move si to after 'CAT'
+
+   call disk_load_file
+   mov si, file_buffer
+   mov cx, [file_length]
+   call text_print_raw
+
+   popa
+   ret
+
+util_ls:
+   pusha
+
+   call disk_clear_output_buffer
+   call disk_list_contents
+
+   mov si, output_buffer
+   call os_print_string
+
+   popa
+   ret
+

source/kernel/kernel.asm

@@ -1,17 +1,17 @@
 ORG 00h
 BITS 16
-root_buffer equ 24000h
+root_buffer: equ 24000h ; Stores a dump of the root directory
-data_buffer equ 26000h
+metadata_buffer: equ 27000h ; Stores metadata about whatever's in the data buffer
+output_buffer: equ 27020h ; Buffer storing stuff you'll output
+file_buffer: equ 28000h ; Stores actual data to be read
 
 start:
+   call disk_load_root ; Loads the root directory into disk_buffer for future use
+
    mov si, boot_message
    call os_print_string
-
+   mov si, help_text
-   call disk_load_root ; Loads the root directory into disk_buffer
+   call os_print_string
-
-   ; Physical address = (segment * 16) + offset
-   mov si, file_name
-   call disk_load_file
 
    call os_start_cli
    hlt
@@ -19,31 +19,6 @@ start:
 halt:
    jmp halt
 
-boot_message: db 'OK] Kernel successfully loaded!\n\n', 0
-file_name: db 'hello.cws', 0
-
-; Define Fat12 header
-bdb_oem:                    db 'MSWIN4.1' ; ignore
-bdb_bytes_per_sector:       dw 200h ; = 512d
-bdb_sectors_per_cluster:    db 01h ; sector = cluster
-bdb_reserved_sectors:       dw 01h
-bdb_fat_count:              db 02h  ; We've got a fat1 and fat2
-bdb_dir_entries_count:      dw 0E0h ; Maximum number of root directory entries
-bdb_total_sectors:          dw 0B40h ; = 2880d
-bdb_media_descriptor_type:  db 0F0h ; ignore
-bdb_sectors_per_fat:        dw 09h
-bdb_sectors_per_track:      dw 12h ; = 18d
-bdb_number_of_heads:        dw 02h ; top and bottom of the floppy disk
-bdb_hidden_sectors:         dd 0 ; ignore
-bdb_large_sector_count:     dd 0 ; total sector count for fat32 (0 for fat12 or fat16)
-
-; extended boot record
-ebr_drive_number:           db 0 ; ignore
-                            db 0 ; ignore
-ebr_signature:              db 29h ; boot signature, indicates that the next three fields are present (0x29)
-ebr_volume_id:              db 12h, 34h, 56h, 78h ; unique id for volume tracking
-ebr_volume_label:           db 'CrawShaw OS' ; must be 11 bytes
-ebr_system_id:              db 'FAT12   ' ; must be 8 bytes
 
 ; ------------------------------------------------------------------
 ; FEATURES -- Code to pull into the kernel
@@ -55,7 +30,12 @@ ebr_system_id:              db 'FAT12   ' ; must be 8 bytes
 	%INCLUDE "source/kernel/features/graphics.asm"
 	%INCLUDE "source/kernel/features/disk.asm"
 	%INCLUDE "source/kernel/features/math.asm"
+	%INCLUDE "source/kernel/features/time.asm"
+	%INCLUDE "source/kernel/features/utils.asm"
 ; GAMES -- Games that I wrote for it
 	%INCLUDE "source/kernel/games/pong.asm"
 
+; DATA/VARIABLES
+	%INCLUDE "source/kernel/data.asm"
+