source: xtideuniversalbios/trunk/Configurator/Src/BiosFile.asm @ 181

; Project name  :   XTIDE Univeral BIOS Configurator
; Description   :   Functions for loading and saving BIOS image file.

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; Saves changes to loaded BIOS image file if user wants to do so.
;
; BiosFile_SaveUnsavedChanges
;   Parameters:
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       Nothing
;   Corrupts registers:
;       AX, BX, CX, DX, ES
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_SaveUnsavedChanges:
    push    ds
    push    di
    push    si

    ; Check if saving is needed
    test    WORD [cs:g_cfgVars+CFGVARS.wFlags], FLG_CFGVARS_UNSAVED
    jz      SHORT .Return
    test    WORD [cs:g_cfgVars+CFGVARS.wFlags], FLG_CFGVARS_FILELOADED
    jz      SHORT .Return

    ; Ask if user wants to save
    push    cs
    pop     ds
    push    cs
    pop     es
    call    BiosFile_DoesUserWantToSaveChanges
    jnc     SHORT .Return

    ; Write file
    mov     si, 80h                                 ; DS:SI points to default DTA (DOS PSP:80h)
    mov     di, g_cfgVars+CFGVARS.rgbEepromBuffers  ; ES:DI points to data to save
    call    EEPROM_GenerateChecksum
    call    BiosFile_SaveFile
    jc      SHORT .Return                           ; Return if error

    ; Update unsaved status
    and     WORD [cs:g_cfgVars+CFGVARS.wFlags], ~FLG_CFGVARS_UNSAVED
ALIGN JUMP_ALIGN
.Return:
    pop     si
    pop     di
    pop     ds
    ret

;--------------------------------------------------------------------
; Asks does user want to save changes to BIOS image file.
;
; BiosFile_DoesUserWantToSaveChanges
;   Parameters:
;       ES:     String segment
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       CF:     Set if user wants to save changes
;               Cleared if used does not want to save changes
;   Corrupts registers:
;       AX, BX, CX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_DoesUserWantToSaveChanges:
    mov     bl, WIDTH_DLG           ; Dialog width
    mov     di, g_szDlgSaveChanges  ; ES:DI points to string to display
    jmp     Menu_ShowYNDlg


;--------------------------------------------------------------------
; Saves loaded BIOS image to a file.
;
; BiosFile_SaveFile
;   Parameters:
;       DS:SI:  Ptr to DTA for selected file
;       ES:DI:  Ptr to data to save
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       CF:     Cleared if file saved successfully
;               Set if any error
;   Corrupts registers:
;       AX, BX, CX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_SaveFile:
    ; Open file
    mov     al, VAL_FACCS_WRITE ; Open for writing
    lea     dx, [si+DTA.szFile] ; DS:DX points to ASCIZ file name
    call    File_Open
    jc      SHORT BiosFile_DisplayFileErrorMessage

    ; Save file
    mov     cx, [cs:g_cfgVars+CFGVARS.wEepromSize]
    call    File_Write
    jc      SHORT BiosFile_DisplayFileErrorMessage

    ; Close file
    jmp     SHORT BiosFile_Close


;--------------------------------------------------------------------
; Loads file selected with BiosFile_SelectFile.
;
; BiosFile_LoadFile
;   Parameters:
;       DS:SI:  Ptr to DTA for selected file
;       ES:DI:  Ptr to buffer where to load file
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       CX:     EEPROM size in bytes
;       CF:     Cleared if file loaded successfully
;               Set if any error
;   Corrupts registers:
;       AX, BX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_LoadFile:
    ; Open file
    mov     al, VAL_FACCS_READ  ; Open for reading
    lea     dx, [si+DTA.szFile] ; DS:DX points to ASCIZ file name
    call    File_Open
    jc      SHORT BiosFile_DisplayFileErrorMessage

    ; Load file to buffer
    call    BiosFile_GetFileSizeToCX
    jc      SHORT BiosFile_DisplayFileSizeErrorMessage
    call    File_Read
    jc      SHORT BiosFile_DisplayFileErrorMessage

    ; Close file
BiosFile_Close:
    call    File_Close
    jc      SHORT BiosFile_DisplayFileErrorMessage
    ret


;--------------------------------------------------------------------
; Returns size for selected file and makes sure it is not too large.
;
; BiosFile_GetFileSizeToCX
;   Parameters:
;       DS:SI:  Ptr to DTA for selected file
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       CX:     File size in bytes
;       CF:     Set if file was too large
;               Cleared if supported size
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_GetFileSizeToCX:
    mov     cx, [si+DTA.dwFileSize+2]   ; High word of file size to CX
    test    cx, cx                      ; File larger than 65535 bytes? (clears CF)
    mov     cx, [si+DTA.dwFileSize]     ; Low word of file size to CX
    jnz     SHORT .TooLargeFile
    cmp     cx, MAX_EEPROM_SIZE         ; Too large?
    ja      SHORT .TooLargeFile
    stc
.TooLargeFile:                          ; CF is always cleared when jumping to here
    cmc                                 ; So we invert it
    ret


;--------------------------------------------------------------------
; Displays error messages related to loading files.
;
; BiosFile_DisplayFileErrorMessage
; BiosFile_DisplayFileSizeErrorMessage
;   Parameters:
;       AX:     DOS File I/O error code (BiosFile_DisplayFileErrorMessage only)
;       DS:SI:  Ptr to DTA for selected file
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       CF:     Set since error
;   Corrupts registers:
;       AX, BX, CX, DX
;--------------------------------------------------------------------
BiosFile_DisplayFileErrorMessage:
    call    File_GetErrStr      ; Error string to ES:DI
    jmp     SHORT BiosFile_DisplayErrorMessage
BiosFile_DisplayFileSizeErrorMessage:
    push    cs
    pop     es
    mov     di, g_szErrFileSize
BiosFile_DisplayErrorMessage:
    mov     bl, WIDTH_DLG       ; Dialog width
    call    Menu_ShowMsgDlg
    stc
    ret


;--------------------------------------------------------------------
; Selects BIOS file to be loaded.
;
; BiosFile_SelectFile
;   Parameters:
;       DS:DI   Ptr to MENUPAGEITEM
;       SS:BP:  Ptr to MENUVARS
;   Returns:
;       DS:SI:  Ptr to DTA for selected file
;       CF:     Set if file selected successfully
;               Cleared if user cancellation
;   Corrupts registers:
;       AX, BX, CX, DX, ES
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
BiosFile_SelectFile:
    push    di
    push    cs                              ; Copy string segment...
    pop     es                              ; ...to ES
    mov     di, [di+MENUPAGEITEM.szDialog]  ; ES:DI points to info string
    mov     si, g_szFileSearch              ; DS:SI points to file search string
    mov     bl, WIDTH_DLG                   ; Dialog width
    call    Menu_ShowFileDlg                ; Get DTA to DS:SI
    pop     di
    ret