Changeset 525 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS

Timestamp:

Mar 14, 2013, 9:45:07 PM (12 years ago)

Author:

krille_n_@…

google:author:

krille_n_@hotmail.com

Message:

Changes:

• Made some improvements to the stack switching in Int13h.asm.
• Added a tail-call optimized variant of the CALL_MENU_LIBRARY macro (JMP_MENU_LIBRARY).
• Other optimizations and fixes.

Location:

trunk/XTIDE_Universal_BIOS

Files:

• Inc/RamVars.inc (modified) (1 diff)
• Src/Handlers/Int13h.asm (modified) (4 diffs)
• Src/Handlers/Int13h/AH1Eh_XTCF.asm (modified) (1 diff)

trunk/XTIDE_Universal_BIOS/Inc/RamVars.inc

@@ -37 +37 @@
 struc RAMVARS
 %ifdef RELOCATE_INT13H_STACK
-                        resb    256 ; Size of our stack
-    .rgbTopOfStack:
+                        resb    252
+    .dwStackChangeDSDI:
+    .wStackChangeDI     resb    2   ; Used during stack
+    .wStackChangeDS     resb    2   ; switching only
+    .rgbTopOfStack:                 ; 256 bytes of stack
     .fpInt13hEntryStack resb    4
-    .dwStackChangeDSDI:
-    .wStackChangeDI     resb    2
-    .wStackChangeDS     resb    2
 %endif
     .wDrvDetectSignature:           ; Signature when BIOS is in drive detection mode

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h.asm

@@ -37 +37 @@
 ALIGN JUMP_ALIGN
 Int13h_DiskFunctionsHandlerWithStackChange:
-    push    ds
+    sti         ; Enable interrupts
+    ; TODO: Maybe we need to save Flags (DF) as well?
+    push    ds  ; Save DS:DI on the original stack
     push    di
     call    RamVars_GetSegmentToDS
 
     ; Store entry registers to RAMVARS
+%ifdef USE_386
+    pop     DWORD [RAMVARS.dwStackChangeDSDI]
+%else
+    pop     WORD [RAMVARS.wStackChangeDI]   ; Pop DS:DI to the top of what
+    pop     WORD [RAMVARS.wStackChangeDS]   ; is to become the new stack
+%endif
     mov     [RAMVARS.fpInt13hEntryStack], sp
     mov     [RAMVARS.fpInt13hEntryStack+2], ss
-    pop     WORD [RAMVARS.wStackChangeDI]
-    pop     WORD [RAMVARS.wStackChangeDS]
 
     ; Load new stack and restore DS and DI
-    mov     di, ds      ; We do not want to overwrite DS and DI in stack
-    mov     ss, di
-    mov     sp, RAMVARS.rgbTopOfStack
-    lds     di, [RAMVARS.dwStackChangeDSDI]
+    mov     di, ds      ; We can save 2 bytes by using PUSH/POP but it's slower
+    mov     ss, di      ; No need to wrap with CLI/STI since this is for AT only (286+)
+    mov     sp, RAMVARS.rgbTopOfStack-4
+    pop     di          ; DI before stack change
+    pop     ds          ; DS before stack change
 
     ; Call INT 13h
@@ -59 +66 @@
 
     ; Restore stack (we must not corrupt FLAGS!)
-    cli
 %ifdef USE_386
     lss     sp, [ss:RAMVARS.fpInt13hEntryStack]
 %else
+    cli
     mov     sp, [ss:RAMVARS.fpInt13hEntryStack]
     mov     ss, [ss:RAMVARS.fpInt13hEntryStack+2]
-%endif
-    pop     di          ; DI before stack change
-    pop     ds          ; DS before stack change
+    sti
+%endif
     retf    2           ; Skip FLAGS from stack
 %endif ; RELOCATE_INT13H_STACK
@@ -88 +94 @@
 ALIGN JUMP_ALIGN
 Int13h_DiskFunctionsHandler:
+%ifndef RELOCATE_INT13H_STACK
     sti                                 ; Enable interrupts
+%endif
     cld                                 ; String instructions to increment pointers
     CREATE_FRAME_INTPACK_TO_SSBP    SIZE_OF_IDEPACK_WITHOUT_INTPACK
@@ -398 +406 @@
     dw  AH1Eh_HandlerForXTCFfeatures                ; 1Eh, Lo-tech XT-CF features (XTIDE Universal BIOS)
 %else
-    dw  UnsupportedFunction                         ; 1Eh, 
+    dw  UnsupportedFunction                         ; 1Eh,
 %endif
     dw  UnsupportedFunction                         ; 1Fh,

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH1Eh_XTCF.asm

@@ -112 +112 @@
     jae     SHORT .SetMemoryMappedMode
 
-; We need to limit block size here. Consider this scenario;
-; 1. While in PIO mode or memory mapped mode, the drive is set to do
-;    block transfers larger than XTCF_DMA_MODE_MAX_BLOCK_SIZE.
-; 2. A call is subsequently made to change device mode to DEVICE_8BIT_XTCF_DMA.
-; 3. The call to AH24h_SetBlockSize fails but the change in device mode has been made.
-
     ; Set DMA Mode
     mov     BYTE [di+DPT_ATA.bDevice], DEVICE_8BIT_XTCF_DMA
     mov     al, [di+DPT_ATA.bBlockSize]
-    MIN_U   al, XTCF_DMA_MODE_MAX_BLOCK_SIZE
-    jmp     SHORT AH24h_SetBlockSize    ; Returns via AH23h_Enable8bitPioMode
+    cmp     al, XTCF_DMA_MODE_MAX_BLOCK_SIZE
+    jbe     SHORT AH24h_SetBlockSize
+    mov     al, XTCF_DMA_MODE_MAX_BLOCK_SIZE
+    jmp     SHORT AH24h_SetBlockSize
 
 .SetMemoryMappedMode: