Changeset 593 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Initialization/AdvancedAta/AdvAtaInit.asm

Timestamp:

Jun 30, 2018, 8:27:04 AM (7 years ago)

Author:

Tomi Tilli

Message:

Flashing now works again.
Hack to get Windows 95 to work properly (MODULE_WIN95_CMOS_HACK included for 386 builds by default).
Edited makefile to produce large 386 build.
Fixed recovery time for QDI Vision VLB-IDE controllers.
No more warnings with Nasm 2.13.xx and later.
File dialog now properly restores default drive when file selection is cancelled.

File:

• trunk/XTIDE_Universal_BIOS/Src/Initialization/AdvancedAta/AdvAtaInit.asm (modified) (2 diffs)

trunk/XTIDE_Universal_BIOS/Src/Initialization/AdvancedAta/AdvAtaInit.asm

@@ -33 +33 @@
 ;               Cleared if no controller
 ;   Corrupts registers:
-;       BX
+;       BX, CX
 ;--------------------------------------------------------------------
 AdvAtaInit_DetectControllerForIdeBaseInBX:
+    ; Detect if system has PCI bus. If it does, we can skip VLB detection. This is
+    ; good thing since detecting Vision QD6850 is dangerous since Intel PIIX4 south bridge
+    ; mirrors Interrupt Controller registers from Axh to Bxh. This can lead to faulty
+    ; detection of QD6850 that will eventually crash the system when ports are written.
+
+    ; We should save the 32-bit registers but we don't since system BIOS has stored
+    ; them already and we don't use the 32-bit registers ourselves anywhere at the moment.
+    push    bx
+    push    di
+    xor     edi, edi        ; Some BIOSes require this to be set to zero
+    mov     ax, PCI_INSTALLATION_CHECK
+    int     BIOS_TIME_PCI_PNP_1Ah
+    pop     di
+    pop     bx
+    test    ah, ah
+    jz      SHORT .ThisSystemHasPCIbus
+
+    ; Detect VLB controllers
     call    Vision_DetectAndReturnIDinAXandPortInDXifControllerPresent
     jnz     SHORT .NoVisionControllerFound
@@ -51 +69 @@
 
 .NoAdvancedControllerForPortBX:
+.ThisSystemHasPCIbus:
     xor     ax, ax      ; Clear ID in AX and CF
     ret