Changeset 518 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS_Configurator_v2/Src

Timestamp:

Mar 4, 2013, 5:11:47 PM (12 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to Configurator v2:

• CF is now always cleared when XTIDE rev 1 is detected.

File:

• trunk/XTIDE_Universal_BIOS_Configurator_v2/Src/IdeAutodetect.asm (modified) (6 diffs)

trunk/XTIDE_Universal_BIOS_Configurator_v2/Src/IdeAutodetect.asm

@@ -21 +21 @@
 SECTION .text
 
+IDE_PORT_TO_START_DETECTION         EQU 00h     ; Must be zero (not actual port)
+FIRST_MEMORY_SEGMENT_ADDRESS        EQU 0C000h
+
 ;--------------------------------------------------------------------
 ; IdeAutodetect_DetectIdeDeviceFromPortDXAndReturnControlBlockInSI
@@ -65 +68 @@
     call    CompareIdeStatusRegistersFromALandAH
     mov     al, DEVICE_8BIT_JRIDE_ISA   ; Assume CF was cleared
+    mov     si, dx                      ; For IDEDTCT.COM
     ret                                 ; No need to return Control Block Port
 
@@ -143 +147 @@
     mov     al, DEVICE_8BIT_XTIDE_REV1  ; We must have rev 1
 .IdeDeviceFound:
+    clc
     ret
 
@@ -191 +196 @@
     ; They must be the same if base port was in use by IDE device.
     cmp     al, ah
-    jne     SHORT .InvalidStatusRegister
+    jne     SHORT NoIdeDeviceFound
 
     ; Bytes were the same but it is possible they were both FFh, for
     ; example. We must make sure bits are what is expected from valid
     ; IDE Status Register. So far all drives I've tested return 50h
-    ; (FLG_STATUS_DRDY and FLG_STATUS_DSC set) unless there is only
-    ; one drive present but wrong drive is selected. For example if Master
+    ; (FLG_STATUS_DRDY and FLG_STATUS_DSC set) or 00h.
+    ; I suspect that the zero might mean non available drive is selected. For example if Master
     ; drive is present but Slave is selected from IDE Drive and Head Select Register,
-    ; then the Status Register can be 00h.
+    ; then the Status Register can be 00h. We cannot accept 00h as valid byte
+    ; since that can easily cause invalid JR-IDE/ISA detections.
     test    al, FLG_STATUS_BSY | FLG_STATUS_DF | FLG_STATUS_DRQ | FLG_STATUS_ERR
     jnz     SHORT .InvalidStatusRegister    ; Busy or Errors cannot be set
@@ -206 +212 @@
     ret                                     ; Return with CF cleared
 
-.InvalidStatusRegister:
 NoIdeDeviceFound:
     stc
@@ -247 +252 @@
 ; IdeAutodetect_IncrementDXtoNextIdeBasePort
 ;   Parameters:
-;       DX:     Previous IDE Base Port
+;       DX:     Previous IDE Base Port or IDE_PORT_TO_START_DETECTION
 ;   Returns:
 ;       DX:     Next IDE Base Port