Changeset 487 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS

Timestamp:

Dec 5, 2012, 5:54:46 PM (12 years ago)

Author:

aitotat@…

google:author:

aitotat@gmail.com

Message:

Changes to XTIDE Universal BIOS:

• ATA ID verification no longer checks ATA version since it is not available on CF cards.

Location:

trunk/XTIDE_Universal_BIOS

Files:

• Inc/Controllers/XTCF.inc (modified) (1 diff)
• Src/Initialization/AtaID.asm (modified) (1 diff)

trunk/XTIDE_Universal_BIOS/Inc/Controllers/XTCF.inc

@@ -23 +23 @@
 %define XTCF_INC
 
-XTCF_DMA_MODE_MAX_BLOCK_SIZE        EQU     64      ; Sectors
 OFFSET_TO_CONTROL_BLOCK_REGISTERS   EQU     8
 DEFAULT_XTCF_SECTOR_WINDOW_SEGMENT  EQU     0D800h
+
+; XT-CF requires that block must be less than 128 sectors (64 kiB).
+; Instead of limiting block size to 64, we limit it to 32 (16 kiB).
+; Transferring more than 16 kiB with 8237 DMA controller block or demand
+; mode might interfere with DRAM refresh on XT systems.
+XTCF_DMA_MODE_MAX_BLOCK_SIZE        EQU     32      ; Sectors
 
 ; Possible base addresses. Note that all XT-CF IDE registers are SHL 1 compared

trunk/XTIDE_Universal_BIOS/Src/Initialization/AtaID.asm

@@ -52 +52 @@
     call    .CompareCHorSfromOffsetBXtoMaxValueInCX
 
-    ; We now verified P-CHS parameters so we assume ATA ID to be valid
-    ; for ATA-4 and older. For ATA-5 and later we check signature
-    ; and checksum.
-    mov     ax, [es:si+ATA6.wMajorVer]          ; ATA-3 and later have this word
-    inc     ax
-    jz      SHORT .AtaIDverifiedSuccessfully    ; FFFFh means no version info available
-    dec     ax
-    jz      SHORT .AtaIDverifiedSuccessfully    ; Zero means no version info available
-    cmp     ax, A6_wMajorVer_ATA5
-    jb      SHORT .AtaIDverifiedSuccessfully    ; ATA-3 and ATA-4 do not have checksum
-
-    ; Check signature byte
-    cmp     BYTE [es:si+ATA6.bSignature], A6_wIntegrity_SIGNATURE
+    ; Check signature byte. It is only found on ATA-5 and later. It should be zero on
+    ; ATA-4 and older.
+    mov     al, [es:si+ATA6.bSignature]
+    test    al, al
+    jz      SHORT .AtaIDverifiedSuccessfully    ; Old ATA so Signature and Checksum is not available
+    cmp     al, A6_wIntegrity_SIGNATURE
     jne     SHORT .FailedToVerifyAtaID
 
-    ; Check checksum byte
+    ; Check checksum byte since signature was present
     mov     cx, ATA6_size
     call    Memory_SumCXbytesFromESSItoAL       ; Returns with ZF set according to result