Power-Programmierung/CD1.mdf/magazine/pcmagazi/1990/16/install.asm

Assembly Source File | 1990-06-28 | 20KB | 716 lines

; INSTALL.ASM
; (c) 1989, 1990 Ashok P. Nadkarni
;
; This code is the installation code for CMDEDIT. This file must be
; linked last !

    INCLUDE common.inc
    INCLUDE ascii.inc
    INCLUDE dos.inc
    INCLUDE general.inc

    PUBLIC    install_begin
    PUBLIC    install
    PUBLIC    file_error
    PUBLIC    abort_install
    PUBLIC    dirstk_error
    PUBLIC    process_args

CSEG    SEGMENT    PARA PUBLIC 'CODE'
    EXTRN    getargs:PROC
    EXTRN    cmdlen:BYTE
    EXTRN    default_imode:BYTE
    EXTRN    auto_recall:BYTE
    EXTRN    pgm_name:BYTE
    EXTRN    silent:BYTE
    EXTRN    macrosize:WORD
    EXTRN    macro_ignore_char:BYTE
    EXTRN    symsize:WORD
    EXTRN    dossize:WORD
    EXTRN    dirsize:WORD
    EXTRN    mfilename:BYTE
    EXTRN    mfile_seen:BYTE
    EXTRN    prev_isr1b:WORD
    EXTRN    enable_dircmds:BYTE
    EXTRN    dos_version_major:BYTE
    EXTRN    dos_version_minor:BYTE
    EXTRN    old_int21vec:WORD
    EXTRN    cmdedit:PROC
    EXTRN    our_break_handler:PROC
    EXTRN    init_over:PROC
    EXTRN    cmdedit_isr:PROC

DGROUP    GROUP    CSEG


    ASSUME    CS:DGROUP,DS:DGROUP,ES:DGROUP,SS:DGROUP

; install_begin MUST be start of installation code.
install_begin    LABEL BYTE
msg_nomem    db    '* Insufficient Memory - Reduce buffer sizes *',CR,LF,DOLLAR
option_error db '* Unknown or illegal options *',CR,LF,DOLLAR
file_error   db '* Error processing command file *',CR,LF,DOLLAR
dirstk_error db '* Error processing directory stack commands *',CR,LF,DOLLAR
inv_dosver   db '* Unsupported DOS version. *',CR,LF,DOLLAR
msg_dup         db '* CMDEDIT already installed in memory. *',CR,LF,DOLLAR
options_dup  db '* Only options /g /i /r /p may be specified. *',CR,LF,DOLLAR
msg_notdup   db '* No copy of CMDEDIT found in memory. *',CR,LF,DOLLAR
msg_unload   db '* Unable to unload CMDEDIT.        *',CR,LF
         db '* Uninstall TSRs in reverse order.    *',CR,LF,DOLLAR
msg_memerr   db '* DOS memory allocation error! *',CR,LF,BEL
         db '* Recommend you reboot!        *',CR,LF,BEL,DOLLAR
msg_uninstalled db '* CMDEDIT uninstalled successfully *',CR,LF,DOLLAR
msg_omode db '* Default overwrite mode enabled. *',CR,LF,DOLLAR
msg_imode db '* Default insert mode enabled. *',CR,LF,DOLLAR
msg_enable_autorecall db '* CMDEDIT autorecall enabled. *',CR,LF,DOLLAR
msg_disable_autorecall db '* CMDEDIT autorecall disabled. *',CR,LF,DOLLAR
msg_enable_bell db '* CMDEDIT error bell enabled. *',CR,LF,DOLLAR
msg_disable_bell db '* CMDEDIT error bell disabled. *',CR,LF,DOLLAR
msg_ignore_char db '* CMDEDIT ignore character changed. *',CR,LF,DOLLAR

cmdedit_seg  dw    0                ;Segment of the first copy
;                         of CMDEDIT loaded into memory.

argflags     db    0    ;Used to remember what args have been seen.
dosarg        equ    1
applarg        equ    2
filearg        equ    4
dirarg        equ    8
macroarg    equ    16
symarg        equ    32
uninstall_arg    equ    64
ignore_arg    equ    128

argument_buffer db    LINEBUF_SIZE DUP (?)

;    This location is jumped to when the program is run from the DOS
;    command line. The program parses the input line, takes
;    appropriate actions, initializes buffers etc. and then TSR's
;    after taking over interrupt 21h. The memory taken up by the ISEG
;    segment will then be used for various data buffers since this
;    code is no longer needed.
install proc    near
    cld            ;Entire program assumes direction flag will
;                 be cleared

    ASSUME CS:DGROUP,DS:DGROUP,ES:DGROUP,SS:DGROUP
    @DispStr pgm_name        ;Display program name

; Make sure we are running DOS 2.x or higher
    call    near ptr get_dosversion
    cmp    dos_version_major,1        ;DOS 1.x ?
    jne    @install_1
    @DispStr inv_dosver
    mov    ax,-1
    jmp    abort_install            ;V1.x not supported.

@install_1:
; Locate the segment of the first copy of CMDEDIT in memory so that
; we can tell if this is a second copy.
    call    near ptr locate_cmdedit
    mov    cmdedit_seg,ax            ;Remember it

@install_5:
    mov    si,offset cmdlen ;
    lodsb            ;SI == line in PSP, AL == line length
    mov    cl,al
    xor    ch,ch        ;CX = line length
    xor    ax,ax        ;Function = get argument count
    push    cx        ;Save line length
    call     near ptr getargs ;AX := # arguments in command line
    pop    cx        ;Restore line length
    mov    di,ax        ; DI == number of arguments
    inc    di        ;Prime for loop
@install_10:
    dec    di        ;Any more arguments ?
    jz    @install_20    ;No
    mov    bx,offset DGROUP:argument_buffer
    mov    dx,SIZE argument_buffer
    mov    ax,di        ;Argument number
    push    cx        ;save line length
    call     near ptr getargs ;Get argument into argument_buffer
;                  (no chance of buffer being too short)
    call     near ptr process_args ;Process the argument
    pop    cx        ;Restore line length
    jmp    short @install_10 ;loop back to process remaining args


@install_20:
; OK now we have done all necessary parsing without errors. Now first check
; if the uninstall option was specified.
    test    argflags,uninstall_arg
    je    @install_21        ;Nope

; We have to unload a previously installed copy of CMDEDIT. See if it is
; really there.
    mov    ax,ds            ;Are we the only copy of CMDEDIT ?
    cmp    ax,cmdedit_seg
    je    @install_20_a        ;There is no other copy
    jmp    uninstall

@install_20_a:
    @DispStr msg_notdup        ;Indicate no copy to uninstall
    mov    ax,-1
    jmp    abort_install        ;Exit

@install_21:
; No uninstall option specified. Now check if this is the only copy of
; CMDEDIT.
    mov    ax,ds
    cmp    ax,cmdedit_seg
    je    @install_21_a        ;We are the only copy. Proceed with
;                     installation
    jmp    change_installed_options ;Else go change installed options.

@install_21_a:
; At this point all the arguments have been parsed. Now check
; that the sum total of the various buffer sizes does not exceed
; segment limits. Also check for mandatory minimum sizes.
; Finally, transfer control to the resident portion which will
; relocate buffers to overlay the installation code.

    mov    ax,OFFSET DGROUP:install_begin
                    ;add starting address where buffers
                    ; will begin
    add    ax,STACK_SIZE
    jnc    @install_23
    jmp    @install_125
@install_23:
    cmp    macrosize,MACROSIZE_MIN
    jnb    @install_22
    mov    macrosize,MACROSIZE_MIN ;Ensure min buffer sizes
@install_22:
    add    ax,macrosize
    jc    @install_125
    cmp    symsize,SYMSIZE_MIN
    jnb    @install_24
    mov    symsize,SYMSIZE_MIN ;Ensure min buffer sizes
@install_24:
    add    ax,symsize
    jc    @install_125
    cmp    dossize,DOSSIZE_MIN
    jnb    @install_26
    mov    dossize,DOSSIZE_MIN ;Ensure min buffer sizes
@install_26:
    add    ax,dossize
    jc    @install_125
    cmp    dirsize,DIRSIZE_MIN
    jnb    @install_30
    mov    dirsize,DIRSIZE_MIN ;Ensure min buffer sizes
@install_30:
    add    ax,dirsize
    jc    @install_125
;Enough memory, so keep resident. Install our Ctrl-Break handler.
    push    es            ;Save ES
    mov    ah,35h
    mov    al,1bh            ;Ctrl-Break Interrupt
    int    21h            ;Get current handler address
    mov    CS:prev_isr1b,bx    ;Offset of previous handler
    mov    CS:prev_isr1b+2,es    ;Segment of previous handler
    pop    es            ;Restore es
    mov    dx,offset CS:our_break_handler
    push    ds            ;Save DS
    mov    ax,cs
    mov    ds,ax            ;DS:DX->our break handler
    mov    al,1bh
    mov    ah,25h            ;Set up our break handler
    int    21h
    pop    ds            ;Restore DS
;
    jmp    near ptr init_over



@install_125:
    @DispStr msg_nomem
    mov    ax,-1
    jmp    abort_install

install endp




;+
; FUNCTION : process_args
;
;    Processes the argument pointed to by BX. AX contains length
;    of argument. If a previously seen argument is repeated, it is
;    ignored (ie. the old value is kept). Note that the argument is
;    assumed not to contain any delimiters (like space or tab).
;
;    Options start with either a '-' or '/'. Any associated value must
;    follow immediately after without any intervening space/tab.
;        /f    Macro file to be read.
;        /d    DOS history buffer size
;        /a    Application history buffer size (only if
;            separate histories maintained) (OUTDATED)
;        /m    Macro buffer size
;        /b    symbol buffer size
;        /s    Directory Stack size
;        /r    Auto recall mode
;        /i    Insert mode default
;        /g    Silent mode
;        /p    macro ignore character
;        /e    Enable dir commands all the time (OUTDATED)
;        /u    Uninstall CMDEDIT
;
;    Invalid options result in program abortion. If an option is not
;    followed by a value, the default value for the option is assumed.
;
;    Note that this is NOT a general purpose getopt type routine.
;
; Parameters:
;    BX    = Pointer to argument
;    AX    = Number of characters in argument
;
; Returns:
;    Nothing.
;    Various globals may be set according to the specified argument.
; Register(s) BX (call to aton),CX  are destroyed.
;-
process_args proc near
    @save    si,di
    test    argflags,uninstall_arg
    jne    @process_args_5    ;If /U specified, no other arg is allowed

    xchg    ax,cx        ;CX = character count
    sub    cx,2        ;Delete switch char and option letter
    jb    @process_args_5    ;Error in option specification
                ;  if num chars less than 2
    mov    si,bx        ;SI = arg buffer address
    lodsb            ;AL = first character
    cmp    al,'/'        ;Should be either '/'
    je    @process_args_10 ;
    cmp    al,'-'        ; or '-'
    jne    short @process_args_5    ;Else error

@process_args_10:            ;Saw a valid switch char
    lodsb                ;AL = option letter
    or    al,32            ;Lowercase (non alphabetic will be
                    ; ignored anyway)
    cmp    al,'u'            ;Uninstall option ?
    jne    @process_args_11_a    ;No
    or    cx,cx            ;Ok if no more chars in arg
    jne    short @process_args_5    ;Else error

@process_args_11:
    or    argflags,uninstall_arg    ;Indicate /U seen
    jmp    @process_args_50    ;Return

@process_args_11_a:
    cmp    al,'i'            ;insert mode option ?
    jne    @process_args_14    ;No
    jcxz    @process_args_12    ;Ok if no more chars in arg
@process_args_5:
; Error processing
    @DispStr option_error
    mov    ax,-1
    jmp    abort_install
@process_args_12:
    mov    default_imode,1        ;Change default insrt mode
    jmp    @process_args_50    ;Return
@process_args_14:
    cmp    al,'g'            ;silent mode option ?
    jne    @process_args_15    ;No
    jcxz    @process_args_14_a    ;Ok if no more chars in arg
    jmp    short @process_args_5    ;Else error
@process_args_14_a:
    mov    silent,1        ;Silent mode
    jmp    @process_args_50    ;Return
@process_args_15:
    cmp    al,'r'            ;auto-recall option ?
    jne    @process_args_18    ;No
    jcxz    @process_args_16    ;Ok if no more chars in arg
    jmp    short @process_args_5    ;Else error
@process_args_16:
    mov    auto_recall,1        ;Set auto-recall mode
    jmp    @process_args_50    ;Return
@process_args_18:
    cmp    al,'e'            ;Enable dir commands option?
    jne    @process_args_18_b    ;No
    jcxz    @process_args_18_a    ;OK if no more chars
    jmp    short @process_args_5    ;Else error
@process_args_18_a:
    mov    enable_dircmds,1    ;enable directory commands
    jmp    @process_args_50    ;Return
@process_args_18_b:
    cmp    al,'p'            ;ignore character option
    jne    @process_args_19
    cmp    cx,1            ;Should be only one more char
    jne    @process_args_5        ;Error
    lodsb
    or    argflags,ignore_arg    ;Indicate that an ignore char set
    mov    macro_ignore_char,al
    jmp    @process_args_50    ;Return
@process_args_19:
    cmp    al,'f'            ;Is it the macro file option ?
    jne    @process_args_20
    test    argflags,filearg    ;Already seen file argument ?
    je    @process_args_19_a    ;No, then update
    jmp    @process_args_50    ;Yes, then don't update
@process_args_19_a:
    or    argflags,filearg    ;Remember we've seen this option
    jcxz    @process_args_50    ;If 0 count, no file to be read
    cmp    cx,63            ;Max path length must be < 64
    ja    @process_args_5        ;Error
    mov    di,offset mfilename    ;Temp storage for filename
    rep    movsb            ;Copy file name
    mov    byte ptr [di],0        ;Terminate with a NULL char
    mov    mfile_seen,1        ;Indicate that init file specified
    jmp    short @process_args_50
@process_args_20:
    push    ax        ;Save the option letter
    xchg    ax,cx        ;AX = num of char
    call    near ptr aton    ;All other options are numeric values
    jnc    @process_args_22 ;No Errors
    jmp    @process_args_5            ;Error
@process_args_22:
;AX contains numeric value
    xchg    ax,cx        ;CX = numeric value
    pop    ax        ;Restore option letter

    cmp    al,'d'        ;Is it the dos history size option ?
    jne    @process_args_25
    test    argflags,dosarg ;Already seen argument ?
    jne    @process_args_50 ;Yes, then don't update
    or    argflags,dosarg ;Remember we've seen this option
    mov    dossize,cx
    jmp    short @process_args_50
@process_args_25:
    cmp    al,'m'        ;Is it the macro buf size option ?
    jne    @process_args_35
    test    argflags,macroarg ;Already seen argument ?
    jne    @process_args_50 ;Yes, then don't update
    or    argflags,macroarg ;Remember we've seen this option
    mov    macrosize,cx
    jmp    short @process_args_50

@process_args_35:
    cmp    al,'b'        ;Is it the symbol buf size option ?
    jne    @process_args_40
    test    argflags,symarg ;Already seen argument ?
    jne    @process_args_50 ;Yes, then don't update
    or    argflags,symarg ;Remember we've seen this option
    mov    symsize,cx
    jmp    short @process_args_50

@process_args_40:
    cmp    al,'s'        ;Is it the dir stack option ?
    je    @process_args_55 ;Yes
    jmp    @process_args_5  ;Invalid arg
@process_args_55:
    test    argflags,dirarg ;Already seen argument ?
    jne    @process_args_50 ;Yes, then don't update
    or    argflags,dirarg ;Remember we've seen this option
    mov    dirsize,cx

@process_args_50:

    @restore
    ret
process_args endp


;+
; FUNCTION : aton
;
;    Returns the positive integer value of an ASCII string. The value
;    must be between 0 and 65535. If length of string is 0, then a 0
;    value is returned with no error flags.
;
; Parameters:
;    SI    := address of first character in string
;    AX    := count of characters
;
; Returns:
;    AX = 16 bit result if no errors.
;    CF = 1 if error (magnitude too large, invalid character etc.)
;         0 if no errors.
; Register(s) CX,DX  are destroyed.
;-
aton    proc    near
    @save    si,di
    xor    di,di        ;Result
    xchg    ax,cx        ;CX <- num of chars
    jcxz    @aton_99    ;No chars, result = 0 (CF is also 0)
    cmp    cx,6        ;Shouldn't be more'n 5 chars
    cmc            ;CF=1 if error
    jb    @aton_99    ;Error exit
@aton_10:
    lodsb            ;al = char
    sub    al,'0'        ;Is ASCII value < '0'
    jb    @aton_99
    mov    dx,9        ;Comparison with 9, NOT '9'
    cmp    dl,al
    jb    @aton_99    ;Not valid char
    xor    ah,ah
    inc    dx        ;DX = 10 (multiplier)
    xchg    ax,di        ;ax = result so far
    mul    dx        ;Multiply by 10
    jb    @aton_99    ;Overflow
    add    ax,di        ;Add new character
    jb    @aton_99    ;Overflow
    xchg    ax,di        ;Remember new result in di
    loop    @aton_10    ;Go onto next char
@aton_99:
    xchg    ax,di
    @restore
    ret
aton    endp


;+
; FUNCTION : get_dosversion
;
;
; Stores DOS major and minor versions in dos_version_major and
; dos_version_minor.
;-
get_dosversion proc near
    mov    ah,30h
    int    21h
    mov    dos_version_major,al
    mov    dos_version_minor,ah
    ret
get_dosversion endp




;+
; FUNCTION : abort_install
;
;    Called to abort program before installation. Exits to DOS.
;
; Parameters:
;    AL    = Exit code
;
; Returns:
;    Nothing.
;
; Register(s) destroyed:
;    N/A
;-
abort_install proc near
    @Exit
abort_install endp



;+
; FUNCTION : locate_cmdedit
;
;    Called to locate the first copy of CMDEDIT loaded into memory. This
;    is not foolproof in that if CMDEDIT is loaded into high memory
;    using one of the memory managers like QEMM, it will not be found.
;
; Parameters:
;    None.
;
; Returns:
;    AX - segment of first copy of CMDEDIT in memory.
;
; Register(s) destroyed:
;    <TBA>
;-
locate_cmdedit proc near
    @save    si,di,es
    mov    di,offset DGROUP:cmdedit    ;SI and DI will used for
    mov    si,di                ;comparisons
    xor    ax,ax                ;AX will track segments

@locate_cmdedit_5:
    mov    es,ax
    push    si                ;Save offsets that are
;                         compared
    mov    cx,32                ;Count to be matched
    rep    cmpsb
    pop    si                ;Restore offsets that are
;                         compared
    je    @locate_cmdedit_50        ;Matched
    mov    di,si
    inc    ax
    jmp    short @locate_cmdedit_5        ;Try next segment

@locate_cmdedit_50:

    @restore
    ret
locate_cmdedit endp


;+
; FUNCTION : uninstall
;
;    Called to uninstall a previously loaded copy of CMDEDIT.
;    The routine does not return. It exits CMDEDIT.
;
; Parameters:
;    None.
;
; Returns:
;    None.
;
; Register(s) destroyed:
;    <TBA>
;-
uninstall proc near
; Free up the memory occupied by the previous loaded copy of CMDEDIT.
; First give back the all interrupts that were taken over.

; Make sure no one else has taken over the 1b break handler since we
; took it over.
    mov    ax,351bh        ;Retrieve current 1b handler
    int    21h
    cmp    bx,offset our_break_handler ;Is the offset the ours ?
    je    @uninstall_20        ;Yes
@uninstall_10:
; Someone else's taken over the interrupt. Display message and exit.
    @DispStr msg_unload
    mov    ax,-1
    jmp    abort_install
@uninstall_20:
    mov    ax,es            ;Now compare segment
    cmp    ax,cmdedit_seg        ;Is it what we expect?
    jne    @uninstall_10        ;No, display error

; Now check the int 21h handler.
    mov    ax,3521h        ;Retrieve current 1b handler
    int    21h
    cmp    bx,offset cmdedit_isr    ;Is the offset the ours ?
    jne    @uninstall_10        ;No, error
    mov    ax,es            ;Now compare segment
    cmp    ax,cmdedit_seg        ;Is it what we expect?
    jne    @uninstall_10        ;No, display error

; OK, now restore both interrupts
    mov    es,cmdedit_seg        ;ES<-segment of loaded CMDEDIT
    mov    dx,es:prev_isr1b    ;DS:DX->original 1b handler
    mov    ds,es:prev_isr1b+2
    mov    ax,251bh        ;Return int 1b
    int    21h

    mov    dx,es:old_int21vec    ;DS:DX->original int 21h handler
    mov    ds,es:old_int21vec+2
    mov    ax,2521h        ;Return int 21
    int    21h

    push    cs
    pop    ds            ;Restore DS
;
; Finally, return the block of memory taken up by the previous CMDEDIT copy.
    mov    ah,49h            ;Release block function, ES->segment
    int    21h            ;Free the block
    jnc    @uninstall_90        ;No errors
    @DispStr msg_memerr        ;Memory allocation error !
    mov    ax,-1
    jmp    abort_install

@uninstall_90:
    @DispStr msg_uninstalled
    xor    ax,ax

    @Exit    0            ;Exit to DOS

uninstall endp


;+
; FUNCTION : change_installed_options
;
;    Called to change settings on a previously installed copy of
;    CMDEDIT. The function exits to DOS.
;
;    This function allows the following options to be toggled or
;    changed:
;        /r - toggles autorecall mode
;        /i - toggles insert mode
;        /g - toggles silent mode
;        /p - sets a new ignore character
;
;    If any other option is specified, error message is displayed.
;
; Parameters:
;    None.
;
; Returns:
;    Nothing.
;
; Register(s) destroyed:
;    <TBA>
;-

change_installed_options proc near
    @DispStr msg_dup
    mov    al,argflags
    and    al,NOT ignore_arg
    je    @change_installed_options_10
; Unallowed options specified.
    @DispStr options_dup
    mov    ax,-1
    jmp    abort_install

@change_installed_options_10:
    @DispCh LF
; Change the options specified.
    mov    es,cmdedit_seg        ;ES->segment of previously loaded
;                     CMDEDIT
; First toggle the insert mode option. If /i specified, default_imode will
; be 1, else 0. Thus just xor it with the memory resident copy to toggle
; default mode.
    mov    al,es:default_imode
    xor    al,default_imode
    mov    es:default_imode,al    ;Toggle memory resident option
    or    al,al
    je    @change_installed_options_15
    @DispStr msg_imode
    jmp    short @change_installed_options_20
@change_installed_options_15:
    @DispStr msg_omode

@change_installed_options_20:
    mov    al,es:auto_recall
    xor    al,auto_recall
    mov    es:auto_recall,al    ;Toggle memory resident option
    or    al,al
    jne    @change_installed_options_25
    @DispStr msg_disable_autorecall
    jmp    short @change_installed_options_30
@change_installed_options_25:
    @DispStr msg_enable_autorecall

@change_installed_options_30:
; And now for silent mode
    mov    al,es:silent
    xor    al,silent
    mov    es:silent,al    ;Toggle memory resident option
    or    al,al
    je    @change_installed_options_35
    @DispStr msg_disable_bell
    jmp    short @change_installed_options_40
@change_installed_options_35:
    @DispStr msg_enable_bell

@change_installed_options_40:

; Finally change the ignore character if one was specified.
    test    argflags,ignore_arg
    je    @change_installed_options_90 ;None specified
; Change to the new macro ignore char
    mov    al,macro_ignore_char
    mov    es:macro_ignore_char,al
    @DispStr msg_ignore_char

@change_installed_options_90:
; All done
    @Exit    0

change_installed_options endp




CSEG    ENDS

    END