Began moving to C. (No C yet)

If you want to build the assembly version, run the buildAsm.sh script
Currently just setting up the bootloader.

README.md

@@ -38,4 +38,4 @@ _These images may be outdated, Idk_
 ## Known issues
 - If you run the kernel.bin, loading files sorta breaks, because the program is running at 0x8000, but it thinks that it's at 0x2000 (i think)
 - If you run anything in the code editor and return to the kernel, you won't be able to load any files
-- If you type only the starting letters of a command, it will still run (ie. 'he' will run help)
+- If you type only the starting letters of a command, it will still run (i.e. 'he' will run help)

asmSrc/boot.asm

@@ -0,0 +1,98 @@
+[org 0x7c00]
+[bits 16]
+[global start]
+
+start:
+    ; Setup
+    xor ax, ax
+    mov es, ax
+    mov ds, ax
+    mov bp, 0x7c00
+    mov sp, bp
+
+    ; Save drive number
+    mov byte [driveNumber], dl
+
+    ; Print boot message
+    mov si, bootMsg
+    call print
+    mov dl, byte [driveNumber]
+    call printHex
+    mov si, newline
+    call print
+
+    ; Read filetable from disk
+    mov bx, FILETAB_LOC ; Filetable location in memory
+    mov es, bx
+    xor bx, bx
+
+    mov ah, 2           ; Read from disk
+    mov al, 1           ; Read 1 sector (512B)
+
+    mov dl, byte [driveNumber] ; Drive number
+    mov ch, 0           ; Cylinder
+    mov dh, 0           ; Head
+    mov cl, 2           ; Sector
+    int 0x13            ; INT 0x13 - Disk operations
+
+    jc readFail         ; CF will be set if the read fails
+
+    ; Read filetable from disk
+    mov bx, KERNEL_LOC ; Filetable location in memory
+    mov es, bx
+    xor bx, bx
+
+    mov ah, 2           ; Read from disk
+    mov al, 4           ; Read 4 sectors (2kB)
+
+    mov dl, byte [driveNumber] ; Drive number
+    mov ch, 0           ; Cylinder
+    mov dh, 0           ; Head
+    mov cl, 3           ; Sector
+    int 0x13            ; INT 0x13 - Disk operations
+
+    jc readFail         ; CF will be set if the read fails
+
+    ; Setup segmentation
+    mov ax, KERNEL_LOC
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+
+    ; Setup stack
+    mov bp, 0xffff
+    mov sp, bp
+    mov ax, 0x9000
+    mov ss, ax
+
+    mov bl, byte [driveNumber]
+
+    ; Setup video mode
+    mov ax, 0x0003
+    int 0x10
+    mov ah, 0x0b
+    mov bx, 0x0001
+    int 0x10
+
+    ; Far jump to the kernel (never returns)
+    jmp KERNEL_LOC:0x0000
+
+readFail:
+    mov si, diskErrorMsg
+    call print
+    cli
+    hlt
+
+%include "./src/lib/print.asm"
+
+driveNumber: db 0
+
+bootMsg: db ENDL, "Booting kern.", ENDL, "Booting from drive ", 0
+diskErrorMsg: db "Disk Error!", ENDL, 0
+
+FILETAB_LOC equ 0x1000
+KERNEL_LOC equ 0x2000
+
+times 510-($-$$) db 0
+dw 0xaa55

asmSrc/filetable.asm

@@ -0,0 +1,22 @@
+; ------------------
+;  Simple Filetable
+; ------------------
+;
+; 16 Byte entries
+; 0-9   - Filename
+; 10-12 - File extension (type)
+; 13    - Number of filetable entries
+; 14    - Starting Sector
+; 15    - Filesize in sectors (n * 512)
+;
+; ------------------
+
+filetable:
+    ; db 'all',0,0,0,0,0,0,0,'txt',0,1,7 ; all           - start: 1, size: 7
+    db 'boot',0,0,0,0,0,0, 'bin',0,1,1   ; boot.bin      - start: 1, size: 1
+    db 'filetable',0,      'txt',0,2,1   ; filetable.txt - start: 2, size: 1
+    db 'kernel',0,0,0,0,   'bin',0,3,4   ; kernel.bin    - start: 3, size: 4
+    db 'calc',0,0,0,0,0,0, 'bin',0,7,1   ; calc.bin      - start: 7, size: 1
+    db 'edit',0,0,0,0,0,0, 'bin',0,8,4   ; edit.bin      - start: 8, size: 2
+
+times 512-($-$$) db 0

asmSrc/fs/calc.asm

@@ -1,12 +1,21 @@
 [bits 16]
 
 start:
+    pusha
+    
     mov si, msg
     call print
 
     xor ax, ax
     int 0x16
 
+    mov dl, ah
+    call printHexByte
+
+    xor ax, ax
+    int 0x16
+
+    popa
 .return:
     mov ax, 0x2000
     mov ds, ax

asmSrc/fs/edit.asm

@@ -1,10 +1,10 @@
 [bits 16]
 
 start:
+    pusha
     mov byte [driveNum], dl
 
 hexEditor:
-    pusha
     call clearText
 
     mov di, 0x0e60      ; Offset in vidmem (2nd to last line)
@@ -16,6 +16,29 @@ hexEditor:
 
     mov di, hexCode
     xor cx, cx      ; Clear counter
+
+    mov dx, [codeLen]
+    call printHexByte
+    mov si, bytesMsg
+    call print
+    mov si, newline
+    call print
+
+    cmp word [codeLen], 0
+    je getHexCh
+
+    mov cx, [codeLen]
+.printCode:  
+    mov dl, [di]
+    call printHexByte
+    mov ah, 0x0e
+    mov al, ' '
+    int 0x10
+    inc di
+    dec cx
+    jnz .printCode
+
+    mov cx, [codeLen]
 getHexCh:
     xor ax, ax
     int 0x16
@@ -42,7 +65,7 @@ getHexCh:
     mov [hexByte], al
     jmp getHexCh
 .putByte:
-    cmp di, hexCode+256
+    cmp di, hexCode+510
     jge getHexCh    ; Max length reached
     rol byte [hexByte], 4
     or byte [hexByte], al
@@ -50,18 +73,18 @@ getHexCh:
     stosb
     mov dx, [hexByte]
     call printHexByte
-    inc byte [codeLen]
+    inc word [codeLen]
     xor cx, cx
     mov al, ' '
     mov ah, 0x0e
     int 0x10
     jmp getHexCh
 .backspace:
-    mov byte [hexByte], 0
+    cmp word [codeLen], 0 ; Check if there's anything to delete
-    dec byte [codeLen]
-    xor cx, cx
-    cmp di, hexByte     ; Check if there's anything to delete
     je getHexCh         ; If not, ignore
+    mov byte [hexByte], 0
+    dec word [codeLen]
+    xor cx, cx
     mov byte [di], 0
     dec di
     mov si, hexBackspace
@@ -72,7 +95,9 @@ getHexCh:
     call print
 
     pusha
-    call hexCode       ; Call the code
+    push es
+    call hexCode       ;! Runs arbitrary code (may break everything)
+    pop es
     popa
 
     mov si, ranMsg
@@ -80,16 +105,7 @@ getHexCh:
     xor ax, ax
     int 0x16
     jmp hexEditor
-
 return:
-    mov cx, 256
-    mov di, hexCode
-.loop:
-    mov byte [di], 0
-    inc di
-    dec cx
-    jnz .loop
-
     popa
 
     mov ax, 0x2000
@@ -105,7 +121,7 @@ return:
 save:
     mov dl, 9
     mov si, saveFileMsg
-    call getFilename
+    call getInput
     mov byte al, [filename]
     cmp byte al, 0
     je getHexCh
@@ -113,14 +129,17 @@ save:
     ; Call saveFile
     mov byte dl, [driveNum]
     push word filename
-    ; TODO: More filetypes other than .bin
+    push word binFile   ; Filetype, TODO: More filetypes other than .bin
-    push word binFile   ; Filetype
     push word 1         ; TODO: Dynamic filesize
     push word 0x8000    ; Program location (this segment)
-    push word hexCode   ; Offset (hex code location)
+    push word savedData ; Offset (hex code location)
     call saveFile       ; Returns exit code in al
     add sp, 10          ; Stack bs
 
+    mov ax, 0x8000
+    mov es, ax
+    mov fs, ax
+
     cmp al, 0           ; Won't be 1 (File not found) so must be disk error
     jne .error
 
@@ -129,13 +148,14 @@ save:
     mov si, diskErrMsg
     mov di, 0x0f00      ; Last line
     call drawString
+    
     jmp getHexCh
 
 ; Opens a file
 open:
     mov dl, 11
     mov si, openFileMsg
-    call getFilename
+    call getInput
     mov byte al, [filename]
     cmp byte al, 0
     je getHexCh
@@ -143,17 +163,21 @@ open:
     ; Call loadFile
     mov byte dl, [driveNum]
     push word filename
-    push 0x8000
+    push word 0x8000
-    push hexCode
+    push word hexCode
     call loadFile
-    add sp, 8
+
+    mov ax, 0x8000
+    mov es, ax
+    mov fs, ax
 
     cmp al, 1
     je .notFound
     cmp al, 2
     je .diskErr
 
-    jmp getHexCh
+    ; Success
+    jmp hexEditor
 .notFound:
     mov si, notFoundMsg
     jmp .err
@@ -162,7 +186,9 @@ open:
 .err:
     mov di, 0x0f00
     call drawString
-    jmp getHexCh
+    xor ax, ax
+    int 0x16
+    jmp hexEditor
 
 ;
 ; Gets a filename (10 chars, If less, padded with Nulls)
@@ -170,7 +196,7 @@ open:
 ; si - Prompt string (Null terminated)
 ; dl - String offset
 ;
-getFilename:
+getInput:
     pusha
     push es
 
@@ -247,6 +273,9 @@ textModeMsg: db " -- Text -- ", 0
 controlsMsg: db "'$' Execute; ^Q Quit; ^S Save; ^O Open", 0
 saveFileMsg: db "Save as:                              ", 0 ; Make sure to erase the controls
 openFileMsg: db "Open file:                            ", 0
+bytesMsg: db " Bytes", 0
+; savedMsg: db "Saved file as '", 0
+; oepenedMsg: db "Editing file '", 0
 runMsg: db ENDL, ENDL, 0
 ranMsg: db ENDL, ENDL, " - Finished Execution - ", ENDL, 0
 notFoundMsg: db "File not found!           ", 0 ; Erase the user input
@@ -264,7 +293,6 @@ hexByte: db 0
 
 filenameLen: db 0
 filename: times 10 db 0
-codeLen: db 0
 
 ;; Constants
 RUN_CODE equ '$'
@@ -275,5 +303,6 @@ OPEN_FILE equ 'o'
 
 times 3*512-($-$$) db 0
 
-hexCode: times 511 db 0     ; Code buffer
+savedData:
-    ret
+    hexCode: times 510 db 0     ; Code buffer
+    codeLen: dw 0               ; Hopefully we don't overflow :)

asmSrc/kernel.asm

@@ -65,7 +65,27 @@ input:
     cmp byte [inputLen], 0 ; Check if user input something
     je input
 
+tokenize:           ; Tokenize 
+    mov byte cl, [inputLen]
+    mov di, tokens
+.tokenLoop:
+    lodsb
+    cmp al, 0       ; Check for end of input
+    je runCommand
+.wsLoop:
+    cmp al, ' '     ; Compare with whitespace
+    jne .stringLoop
+    lodsb
+    jmp .wsLoop
+.stringLoop:
+    cmp al, ' '
+    je .next
+    
+.next:
+    
+
 ; Runs a command in userInput
+; Expects tokenized input
 runCommand:
     mov di, lsCmd
     call .cmp
@@ -91,6 +111,10 @@ runCommand:
     call .cmp
     je shutdown
 
+    mov di, rmCmd
+    call .cmp
+    je rmFile
+
     jmp .end
 .cmp:
     push cx
@@ -255,6 +279,13 @@ shutdown:
     mov dx, 0x0604
     out dx, ax
 
+;
+; Remove file (rm)
+;
+rmFile:
+    call removeFile
+    jmp input
+
 ;
 ; File list (ls)
 ;
@@ -419,6 +450,7 @@ reboot: jmp 0xffff:0x0000
 ;; Includes
 %include "./src/lib/print.asm"
 %include "./src/lib/screen.asm"
+%include "./src/lib/disk.asm"
 
 ;; Variables
 driveNum: db 0
@@ -441,24 +473,29 @@ helpMsg: db "Available Commands:", ENDL, \
             " gfx    | Graphics mode test", ENDL, \
             " help   | Prints this message", ENDL, \
             " ls     | List all files", ENDL, \
-            " reboot | Reboots the system", ENDL, ENDL, 0
+            " reboot | Reboots the system", ENDL, \
+            " rm     | Removes a file", ENDL, ENDL, 0
 
 ; Commands
 ; TODO: Put these into a file or something
 clearCmd: db "clear", 0
+exitCmd: db "exit"
 gfxCmd: db "gfx", 0
 helpCmd: db "help", 0
 lsCmd: db "ls", 0
-exitCmd: db "exit"
 rebootCmd: db "reboot", 0
+rmCmd: db "rm", 0
 
 ; Files
 fileExt: db "   ", 0
 binExt: db "bin", 0
 txtExt: db "txt", 0
 
+tokens: times 50 db 0 ; char[10][5] (List of 5 strings that are 10 chars long each or null terminated) 
+tokenLen: times 5 db 0 ; 5 lengths for each token
+tokenCount: db 0
 inputLen: db 0
-userInput: db 0
+userInput: times 80 db 0
 
 ;; Constants
 FILETAB_LOC equ 0x1000

asmSrc/lib/disk.asm

@@ -21,9 +21,11 @@ loadFile:
     push es
 
     mov byte [diskNum], dl
-    mov bx, [bp+4]   ; dest Offset
+    mov bx, [bp+4]      ; src Offset
-    mov fs, [bp+6]   ; dest Segment
+    mov fs, [bp+6]      ; src Segment
-    mov si, [bp+8]   ; Filename
+    mov si, [bp+8]      ; Filename
+
+    push bx
 
     mov cx, 10
     mov di, fileName
@@ -47,7 +49,7 @@ loadFile:
 .fileNameCheck:
     mov al, [es:di]
     cmp al, 0       ; End of filetable
-    je .notFound   ; File doesn't exist, create new one
+    je .notFound
 
     cmp al, [si]
     je .beginCmp
@@ -76,11 +78,6 @@ loadFile:
     mov byte [exitCode], NOT_FOUND
     jmp .done
 .found:
-    mov al, [es:di]
-    inc di
-    cmp al, 0       ; Skip NULLs untill extension
-    je .found
-
     add di, 3       ; Skip extension
     inc di          ; Skip Number of entries
 
@@ -88,13 +85,16 @@ loadFile:
     mov dl, [diskNum]
     int 0x13
 
-    mov ax, fs
-    mov es, ax
     mov ch, 0       ; Cylinder
     mov dh, 0       ; Head
     mov cl, [es:di] ; Sector
     inc di
     mov al, [es:di] ; Length in sectors
+    mov bx, fs
+    mov es, bx
+    pop bx
+    mov dx, bx
+    call printHexByte
     mov ah, 2       ; Read from disk
     int 0x13
 
@@ -210,11 +210,6 @@ saveFile:
     jmp .fileNameCheck
 .found:             ; File already exists (override)
     ; TODO: Ask user if they want to override file
-    mov al, [es:di]
-    inc di
-    cmp al, 0       ; Skip NULLs untill extension
-    je .found
-
     add di, 3       ; Skip extension
     inc di          ; Skip Number of entries
 
@@ -236,7 +231,7 @@ saveFile:
     ; jnc returnToCaller
 
     mov byte [exitCode], DISK_ERROR
-    jmp return           ; TODO: Fix this
+    jmp returnToCaller  ; TODO: Fix this
 
 createFile:             ; Appends a file to the filetable.
     mov di, FILETAB_LOC
@@ -309,20 +304,14 @@ returnToCaller:
     mov byte al, [exitCode]
     ret
 
-debug:
+;
-    pusha
+; Removes a file from the disk/filetable
-    mov ah, 0x0e
+;
-    mov bl, 0x1f
+; Params:
-    mov bh, 0
+;   Filename
-.loop:
+;
-    lodsb           ; Load [si] into al; Increment si
+removeFile:
-    or al, al
+    
-    jz .done
-    int 0x10
-    jmp .loop
-.done:
-    popa
-    ret
 
 ;; Variables
 availableSector: db 0

asmSrc/testing/hello.asm

@@ -0,0 +1,25 @@
+[bits 16]
+
+start:
+    mov ah, 0x0e
+    mov al, 'H'
+    int 0x10
+    mov al, 'e'
+    int 0x10
+    mov al, 'l'
+    int 0x10
+    int 0x10
+    mov al, 'o'
+    int 0x10
+    mov al, '!'
+    int 0x10
+
+    xor ax, ax
+    int 0x16
+
+    mov ax, 0x2000
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+    jmp 0x2000:0x0000

build.sh

@@ -11,16 +11,16 @@ nasm -fbin src/boot.asm -o ./build/boot.bin
 nasm -fbin src/filetable.asm -o ./build/filetable.bin
 
 # Kernel
-nasm -fbin src/kernel.asm -o ./build/kernel.bin
+# nasm -fbin src/kernel.asm -o ./build/kernel.bin
 
 # Programs
-nasm -fbin src/fs/calc.asm -o ./build/calc.bin
+# nasm -fbin src/fs/calc.asm -o ./build/calc.bin
-nasm -fbin src/fs/edit.asm -o ./build/edit.bin
+# nasm -fbin src/fs/edit.asm -o ./build/edit.bin
 
-cat ./build/calc.bin ./build/edit.bin > ./build/files.bin
+# cat ./build/calc.bin ./build/edit.bin > ./build/files.bin
 
 # Final binary
-cat ./build/boot.bin ./build/filetable.bin ./build/kernel.bin ./build/files.bin > ./build/temp.bin
+cat ./build/boot.bin ./build/filetable.bin > ./build/temp.bin
 dd if=/dev/zero of=./build/kern.iso bs=512 count=2880
 dd if=./build/temp.bin of=./build/kern.iso conv=notrunc
 rm -rf ./build/**.bin

buildAsm.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+# Create ./build dir if it doesn't exist
+if !(test -d ././build); then
+    mkdir ././build
+    echo "Created ./build/ directory!"
+fi
+
+# Bootloader
+nasm -fbin src/boot.asm -o ./build/boot.bin
+nasm -fbin src/filetable.asm -o ./build/filetable.bin
+
+# Kernel
+nasm -fbin src/kernel.asm -o ./build/kernel.bin
+
+# Programs
+nasm -fbin src/fs/calc.asm -o ./build/calc.bin
+nasm -fbin src/fs/edit.asm -o ./build/edit.bin
+
+cat ./build/calc.bin ./build/edit.bin > ./build/files.bin
+
+# Final binary
+cat ./build/boot.bin ./build/filetable.bin ./build/kernel.bin ./build/files.bin > ./build/temp.bin
+dd if=/dev/zero of=./build/kern.iso bs=512 count=2880
+dd if=./build/temp.bin of=./build/kern.iso conv=notrunc
+rm -rf ./build/**.bin
+
+echo "Built kern.iso!"
+
+# Run QEMU
+echo "Running QEMU..."
+qemu-system-x86_64 -drive format=raw,file="./build/kern.iso",index=0,media=disk -m 256M

src/boot.asm

@@ -2,6 +2,8 @@
 [bits 16]
 [global start]
 
+%define ENDL 0x0A, 0x0D
+
 start:
     ; Setup
     xor ax, ax
@@ -17,7 +19,7 @@ start:
     mov si, bootMsg
     call print
     mov dl, byte [driveNumber]
-    call printHex
+    call printHexByte
     mov si, newline
     call print
 
@@ -84,13 +86,61 @@ readFail:
     cli
     hlt
 
-%include "./src/lib/print.asm"
+;
+; Prints a string
+; si - Pointer to NULL terminated string
+;
+print:
+    pusha
+    mov ah, 0x0e
+    mov bl, 0x1f
+    mov bh, 0
+.loop:
+    lodsb           ; Load [si] into al; Increment si
+    or al, al
+    jz .done
+    int 0x10
+    jmp .loop
+.done:
+    popa
+    ret    
+
+;
+; Prints a hex byte
+; dl - Hex byte
+;
+printHexByte:
+    pusha
+    xor cx, cx
+    mov bh, 0
+    mov bl, 0x1f    ; White on blue
+.loop:
+    mov al, dl
+    and al, 0xF0
+    ror al, 4
+    add al, '0'
+    cmp al, '9'
+    jle .hexNum
+    add al, 7
+.hexNum:
+    mov ah, 0x0e
+    int 0x10
+    inc cx
+    cmp cx, 2
+    je .done
+    ror dl, 4
+    jmp .loop
+.done:
+    popa
+    ret
 
 driveNumber: db 0
 
-bootMsg: db ENDL, "Booting kern.", ENDL, "Booting from drive ", 0
+bootMsg: db ENDL, "Booting kern.", ENDL, "Booting from drive 0x", 0
 diskErrorMsg: db "Disk Error!", ENDL, 0
 
+newline: db ENDL
+
 FILETAB_LOC equ 0x1000
 KERNEL_LOC equ 0x2000