238 lines
No EOL
3.6 KiB
NASM
238 lines
No EOL
3.6 KiB
NASM
;NXOS shell
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;----------
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;Written by: Alberto Venturini (Alb‚) - 2001
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;Email address: -albe-@libero.it
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org 0h
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cld
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Main1:
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mov si,offset Prompt ;shows the prompt
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mov ah,01h
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mov bl,07h
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int 24h
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mov di,offset Command
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xor cx,cx
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GetCommand: ;Get a string from the keyboard
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mov si,offset Command
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mov ah,07h
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int 25h
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dec si
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ToUpCase: ;Turns everything upcase
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inc si
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mov al,ds:[si]
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cmp al,13
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je EndCommand
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cmp al,90
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jbe ToUpCase
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sub al,32
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mov ds:[si],al
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jmp ToUpCase
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EndCommand:
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test cx,cx ;If only CR was pressed, just re-write the prompt
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jz Main1
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push cx
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mov di,offset Command
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Test4Extension: ;tests if file extension is available
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mov al,es:[di]
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cmp al,'.'
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je ExtensionOk
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inc di
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dec cx
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jnz Test4Extension
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NoExtension: ;there's no extension...assume it's an internal
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;shell command
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pop cx
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mov di,offset Command
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mov cx,3
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mov si,offset ClsCmd
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push di
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rep cmpsb
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pop di
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je ShellCommand_Cls
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mov cx,4
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mov si,offset HelpCmd
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push di
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rep cmpsb
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pop di
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je ShellCommand_Help
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mov ah,01h
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mov si,offset Error3
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mov bl,7
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int 24h
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jmp ClearCommandBuffer
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ShellCommand_Cls: ;executes the "CLS" command
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mov ah,04h
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int 24h
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jmp ClearCommandBuffer
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ShellCommand_Help:
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mov si,offset HelpTxt
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mov ah,01h
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mov bl,7
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int 24h
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jmp ClearCommandBuffer
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ExtensionOk: ;there's the extension
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pop cx
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StoreExtension: ;store the extension in a buffer ("Extension")
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push di
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inc di
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mov si,di
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mov di,offset Extension
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movsb
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movsb
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movsb
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pop di
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push di
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sub di,offset Command
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cmp di,8
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jb StoreExtension2
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pop di ;file name must be <= 8
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mov di,offset Command
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add di,8
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jmp StoreExtension3
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StoreExtension2:
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mov cx,8
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sub cx,di
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mov al,' '
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pop di
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rep stosb
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StoreExtension3:
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mov si,offset Extension
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movsb
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movsb
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movsb
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ExecuteProgram:
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mov di,offset Extension
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mov si,offset BinExtension
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mov cx,3
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push di
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rep cmpsb ;tests if the extension is "BIN"
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pop di
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je ExecuteBinProgram
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mov si,offset ComExtension
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mov cx,3
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push di
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rep cmpsb
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pop di
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je ExecuteComProgram
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mov ah,01h
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mov si,offset Error2
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mov bl,7
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int 24h
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jmp Main1
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ExecuteBinProgram:
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push es
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mov si,offset Command
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mov ah,00h
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int 20h
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test dx,dx
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jz FileNotFound
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mov bl,0
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mov ah,01h
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int 20h
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pop es
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jmp ClearCommandBuffer
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ExecuteComProgram:
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push es
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mov si,offset Command
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mov ah,07h
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int 20h
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test dx,dx
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jz FileNotFound
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mov bl,0
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mov ah,01h
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int 20h
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pop es
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jmp ClearCommandBuffer
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FileNotFound:
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pop es
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mov si,offset Error1
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mov ah,01h
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mov bl,7
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int 24h
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ClearCommandBuffer:
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mov di,offset Command
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mov al,' '
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mov cx,95
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ClearCommandBuffer2:
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mov byte ptr cs:[di],al
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inc di
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loop ClearCommandBuffer2
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jmp Main1
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;------------------------------------------------------------------------------
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Command db 100 dup (32)
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Prompt db 13,10,'Ready:',0
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Error1 db 13,10,'File not found',13,10,0
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Error2 db 13,10,'Invalid file name',13,10,0
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Error3 db 13,10,'Invalid command',13,10,0
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NextLine db 13,10,0
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Extension db 3 dup (?)
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BinExtension db 'BIN',0
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ComExtension db 'COM',0
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ClsCmd db 'CLS'
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HelpCmd db 'HELP'
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;------------------------------------------------------------------------------
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;Help text
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HelpTxt db 13,10,'NXOS shell',13,10
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db '-------------',13,10
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db 13,10
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db 'How to use this shell:',13,10
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db 'if you want to execute an external program, just type the',13,10
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db 'file name, with his extension.',13,10
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db 13,10
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db 'Available shell commands:',13,10
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db ' CLS: clears the screen',13,10
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db ' HELP: shows this screen',13,10,0 |