Added some docs and improved editor

src/boot.asm

@@ -59,6 +59,11 @@ start:
     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]

src/fs/calc.asm

@@ -13,7 +13,6 @@ start:
     mov es, ax
     mov fs, ax
     mov gs, ax
-    mov ss, ax
 
     jmp 0x2000:0x0000
 

src/fs/edit.asm

@@ -1,9 +1,16 @@
 [bits 16]
 
 launch:
+    pusha
     call resetTextMode
-    mov si, headerMsg
-    call print
+
+    mov di, 0x0e60      ; Offset in vidmem (2nd to last line)
+    mov si, statusBarMsg
+    call drawString
+    mov di, 0x0f00      ; Last line
+    mov si, controlsMsg
+    call drawString
+
     xor cx, cx
     mov di, hexCode
 
@@ -34,10 +41,9 @@ getHexCh:
     rol byte [hexByte], 4
     or byte [hexByte], al
     mov al, [hexByte]
-    mov [di], al
+    stosb
     mov dx, [hexByte]
     call printHexByte
-    inc di
     xor cx, cx
     mov al, ' '
     mov ah, 0x0e
@@ -54,9 +60,14 @@ getHexCh:
     call print
     jmp getHexCh
 .runInput:
-    mov si, runMsg
+    pusha
+    call hexCode       ; Call the code
+    popa
+
+    mov si, ranMsg
     call print
-    call hexBegin       ; Call the code
+    xor ax, ax
+    int 0x16
     jmp launch
 
 ; Expects al to contain an ASCII character, will set bx to it's hex equivalent
@@ -69,13 +80,24 @@ asciiToHex:
     ret
 
 return:
+    mov cx, 256
+    mov di, hexCode
+.loop:
+    mov byte [di], 0
+    inc di
+    dec cx
+    jnz .loop
+
+    popa
+
     mov ax, 0x2000
+    mov es, bx
+    xor bx, bx
+
     mov ds, ax
     mov es, ax
     mov fs, ax
     mov gs, ax
-    mov ss, ax
-
     jmp 0x2000:0x0000
 
 ; - Includes -
@@ -83,19 +105,15 @@ return:
 %include "./src/lib/print.asm"
 ; ------------
 
-headerMsg: db   " - EDITOR - ", ENDL, \
-                "Type '$' to run your code or '!' to exit", ENDL, ENDL, 0
-runMsg: db ENDL, " -- Executing -- ", ENDL, ENDL, 0
+statusBarMsg: db " -- HEX -- ", 0
+controlsMsg: db "'$' to execute code; '!' to quit", 0
+ranMsg: db ENDL, ENDL, " - Finished Execution - ", ENDL, 0
 
-backChars: db 8, 8, 8, '  ', 8, 8, 0
+backChars: db 8,8,8,'  ',8,8,0
 
 hexByte: db 0
 
-hexBegin: ; The label we jump to
-    pusha
-hexCode: times 256 db 0     ; Code buffer (user input code)
-hexEnd: 
-    popa
+hexCode: times 256 db 0     ; Code buffer
     ret
 
 times 2*512-($-$$) db 0

src/kernel.asm

@@ -182,7 +182,6 @@ foundProgram:
     mov es, ax
     mov fs, ax
     mov gs, ax
-    mov ss, ax
 
     jmp PROGRAM_LOC:0x0000
 .printText:
@@ -385,7 +384,7 @@ driveNumber: db 0
 startMsg: db "kern.", ENDL, ENDL, 0 ; The bootup message
 prompt: db "> ", 0 ; Prompt for input
 fileNotFoundMsg: db "File not found!", ENDL, 0 ; User tries to load nonexistent file
-programLoadFailMsg: db "Failed while loading program!", ENDL, 0 ; File load fail
+programLoadFailMsg: db "Couldn't load file!", ENDL, 0 ; File load fail
 sectorLenText: db "512B", 0
 kilobyteText: db "kB", 0
 oneHalfText: db ".5kB", 0
@@ -394,16 +393,16 @@ fileListMsg: db " Filename      E# St   Size ", ENDL, \
                 "----------    ------- ------", ENDL, 0
 
 helpMsg: db "Available Commands:", ENDL, \
-            "clear - Clears the screen", ENDL, \
-            "gfx - Graphics mode test", ENDL, \
-            "help - Prints this message", ENDL, \
-            "ls - List all files", ENDL, \
-            "reboot - Reboots the system", ENDL, 0
+            " clear  | Clears the screen", ENDL, \
+            " edit   | Opens the code editor", ENDL, \
+            " gfx    | Graphics mode test", ENDL, \
+            " help   | Prints this message", ENDL, \
+            " ls     | List all files", ENDL, \
+            " reboot | Reboots the system", ENDL, ENDL, 0
 
 ; Commands
 ; TODO: Put these into a file or something
 clearCmd: db "clear", 0
-editCmd: db "edit", 0
 gfxCmd: db "gfx", 0
 helpCmd: db "help", 0
 lsCmd: db "ls", 0

src/lib/print.asm

@@ -5,7 +5,7 @@
 print:
     pusha
     mov ah, 0x0e
-    mov bl, 0x0f
+    mov bl, 0x1f
     mov bh, 0
 .loop:
     lodsb           ; Load [si] into al; Increment si
@@ -53,6 +53,8 @@ printHex:
 printHexByte:
     pusha
     xor cx, cx
+    mov bh, 0
+    mov bl, 0x1f    ; White on blue
 .loop:
     mov al, dl
     and al, 0xF0
@@ -84,6 +86,29 @@ clear:
     popa
     ret
 
+;
+; Writes a string into video memory
+; di - Video memory offset
+; si - string
+;
+drawString:
+    pusha
+    push es         ; For some reason doesn't get stored in pusha
+    mov ax, VIDMEM
+    mov es, ax
+.loop:
+    cmp byte [si], 0
+    je .after
+    movsb
+    mov byte [es:di], 0x1f  ; White on blue
+    inc di
+    jmp .loop
+.after:
+    pop es
+    popa
+    ret
+
 ; Usefull definitions
 %define ENDL 0x0a, 0x0d
+VIDMEM equ 0x0b800
 newline: db ENDL, 0 ; CRLF