source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeError.asm @ 238

; Project name  :   XTIDE Universal BIOS
; Description   :   IDE Device error functions.

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; IdeError_GetBiosErrorCodeToAHfromPolledStatusRegisterInAL
;   Parameters:
;       AL:     IDE Status Register contents
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       AH:     BIOS error code
;       CF:     Set if error
;               Cleared if no error
;   Corrupts registers:
;       AL, BX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
IDEDEVICE%+Error_GetBiosErrorCodeToAHfromPolledStatusRegisterInAL:
    mov     ah, al          ; IDE Status Register to AH
    INPUT_TO_AL_FROM_IDE_REGISTER ERROR_REGISTER_in
    xchg    al, ah          ; Status Register now in AL, Error Register now in AH

    ; I don't think anything actually reads these from BDA
    push    ds
    LOAD_BDA_SEGMENT_TO ds, dx
    mov     [HDBDA.wHDStAndErr], ax
    pop     ds

    ; Fall to GetBiosErrorCodeToAHfromStatusAndErrorRegistersInAX


;--------------------------------------------------------------------
; GetBiosErrorCodeToAHfromStatusAndErrorRegistersInAX
;   Parameters:
;       AL:     IDE Status Register contents
;       AH:     IDE Error Register contents
;   Returns:
;       AH:     BIOS INT 13h error code
;       CF:     Set if error
;               Cleared if no error
;   Corrupts registers:
;       BX
;--------------------------------------------------------------------
%ifdef ASSEMBLE_SHARED_IDE_DEVICE_FUNCTIONS
ALIGN JUMP_ALIGN
GetBiosErrorCodeToAHfromStatusAndErrorRegistersInAX:
    test    al, FLG_STATUS_BSY
    jz      SHORT .CheckErrorBitsFromStatusRegisterInAL
    mov     ah, RET_HD_TIMEOUT
    jmp     SHORT .ReturnBiosErrorCodeInAH

ALIGN JUMP_ALIGN
.CheckErrorBitsFromStatusRegisterInAL:
    test    al, FLG_STATUS_DF | FLG_STATUS_CORR | FLG_STATUS_ERR
    jnz     SHORT .ProcessErrorFromStatusRegisterInAL
    xor     ah, ah                  ; No errors, zero AH and CF
    ret

.ProcessErrorFromStatusRegisterInAL:
    test    al, FLG_STATUS_ERR      ; Error specified in Error register?
    jnz     SHORT .ConvertBiosErrorToAHfromErrorRegisterInAH
    mov     ah, RET_HD_ECC          ; Assume ECC corrected error
    test    al, FLG_STATUS_CORR     ; ECC corrected error?
    jnz     SHORT .ReturnBiosErrorCodeInAH
    mov     ah, RET_HD_CONTROLLER   ; Must be Device Fault
    jmp     SHORT .ReturnBiosErrorCodeInAH

.ConvertBiosErrorToAHfromErrorRegisterInAH:
    xor     bx, bx                  ; Clear CF
.ErrorBitLoop:
    rcr     ah, 1                   ; Set CF if error bit set
    jc      SHORT .LookupErrorCode
    inc     bx
    test    ah, ah                  ; Clear CF
    jnz     SHORT .ErrorBitLoop
.LookupErrorCode:
    mov     ah, [cs:bx+.rgbRetCodeLookup]
.ReturnBiosErrorCodeInAH:
    stc                             ; Set CF since error
    ret

.rgbRetCodeLookup:
    db  RET_HD_ADDRMARK     ; Bit0=AMNF, Address Mark Not Found
    db  RET_HD_SEEK_FAIL    ; Bit1=TK0NF, Track 0 Not Found
    db  RET_HD_INVALID      ; Bit2=ABRT, Aborted Command
    db  RET_HD_NOTLOCKED    ; Bit3=MCR, Media Change Requested
    db  RET_HD_NOT_FOUND    ; Bit4=IDNF, ID Not Found
    db  RET_HD_LOCKED       ; Bit5=MC, Media Changed
    db  RET_HD_UNCORRECC    ; Bit6=UNC, Uncorrectable Data Error
    db  RET_HD_BADSECTOR    ; Bit7=BBK, Bad Block Detected
    db  RET_HD_STATUSERR    ; When Error Register is zero
%endif