Changeset 558 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeDmaBlock.asm

Timestamp:

Jun 23, 2013, 3:52:31 PM (12 years ago)

Author:

krille_n_@…

google:author:

krille_n_@hotmail.com

Message:

Changes:

• Building the BIOS Drive Information Tool now works again.
• Moved all XT-CF related code to MODULE_8BIT_IDE_ADVANCED. I don't see how an XT-CF card could work without *_ADVANCED anyway but if I'm wrong, feel free to undo this. Note! The autodetection code in XTIDECFG has NOT been changed to reflect this (still relies on MODULE_8BIT_IDE).
• Optimizations and fixes in general.

File:

• trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeDmaBlock.asm (modified) (7 diffs)

trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeDmaBlock.asm

@@ -1 +1 @@
 ; Project name  :   XTIDE Universal BIOS
-; Description   :   IDE Read/Write functions for transferring
-;           block using DMA.
-;           These functions should only be called from IdeTransfer.asm.
+; Description   :   IDE Read/Write functions for transferring block using DMA.
+;                   These functions should only be called from IdeTransfer.asm.
+
 ; Modified JJP 05-Jun-13
+
 ;
 ; XTIDE Universal BIOS and Associated Tools
@@ -84 +85 @@
     shl     cx, 9                                   ; CX = Block size in BYTEs
 %else
-    xchg        cl, ch
+    xchg    cl, ch
     shl     cx, 1
 %endif
@@ -92 +93 @@
     neg     ax          ; 2s compliment
 
-    ; if DI was zero carry flag will be cleared (and set otherwise)
+    ; If DI was zero carry flag will be cleared (and set otherwise)
     ; When DI is zero only one transfer is required since we've limited the
     ; XT-CFv3 block size to 32k
-    jnc .TransferLastDmaPageWithSizeInCX
+    jnc     SHORT .TransferLastDmaPageWithSizeInCX
 
     ; CF was set, so DI != 0 and we might need one or two transfers
     cmp     cx, ax                                  ; if we won't cross a physical page boundary...
-    jbe SHORT .TransferLastDmaPageWithSizeInCX  ; ...perform the transfer in one operation
+    jbe     SHORT .TransferLastDmaPageWithSizeInCX  ; ...perform the transfer in one operation
 
     ; Calculate how much we can transfer on first and second rounds
-    xchg        cx, ax          ; CX = BYTEs for first page
-    sub     ax, cx          ; AX = BYTEs for second page
-    push        ax          ; Save bytes for second transfer on stack
+    xchg    cx, ax      ; CX = BYTEs for first page
+    sub     ax, cx      ; AX = BYTEs for second page
+    push    ax          ; Save bytes for second transfer on stack
 
     ; Transfer first DMA page
@@ -126 +127 @@
 ;       ES:DI updated (CX is added)
 ;   Corrupts registers:
-;       AX
+;       AX, CX
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
@@ -161 +162 @@
     sti                                                         ; Enable interrupts
 
+    ; Update physical address in ES:DI - since IO might need several calls through this function either from here
+    ; if crossing a physical page boundary, or from IdeTransfer.asm if requested sectors was > PIOVARS.wSectorsInBlock
+    ; We update the pointer here (before the actual transfer) to avoid having to save the byte count on the stack
+    mov     ax, es                      ; copy physical page address to ax
+    add     di, cx                      ; add requested bytes to di
+    adc     al, 0                       ; and increment physical page address, if required
+    mov     es, ax                      ; and save it back in es
+
     ; XT-CF transfers 16 bytes at a time. We need to manually start transfer for every block by writing (anything)
     ; to the XT-CFv3 Control Register, which raises DRQ thereby passing system control to the 8237 DMA controller.
@@ -169 +178 @@
 
 %if 0   ; Slow DMA code - works by checking 8237 status register after each 16-byte transfer, until it reports TC has been raised.
-;ALIGN JUMP_ALIGN
-;.TransferNextBlock:
-;   cli                                 ; We want no ISR to read DMA Status Register before we do
-;   out     dx, al                      ; Transfer up to 16 bytes to/from XT-CF card
-;   in      al, STATUS_REGISTER_DMA8_in
-;   sti
-;   test    al, FLG_CH3_HAS_REACHED_TERMINAL_COUNT
-;   jz      SHORT .TransferNextBlock    ; All bytes transferred?
-%endif ; Slow DMA code
-
-%if 1   ; Fast DMA code - perform computed number of transfers, then check DMA status register to be sure
-    push    cx                          ; need byte count to update pointer at the end
+ALIGN JUMP_ALIGN
+.TransferNextBlock:
+    cli                                 ; We want no ISR to read DMA Status Register before we do
+    out     dx, al                      ; Transfer up to 16 bytes to/from XT-CF card
+    in      al, STATUS_REGISTER_DMA8_in
+    sti
+    test    al, FLG_CH3_HAS_REACHED_TERMINAL_COUNT
+    jz      SHORT .TransferNextBlock    ; All bytes transferred?
+%else   ; Fast DMA code - perform computed number of transfers, then check DMA status register to be sure
     add     cx, BYTE 15                 ; We'll divide transfers in 16-byte atomic transfers,
     eSHR_IM cx, 4                       ; so include any partial block, which will be terminated
@@ -191 +197 @@
     test    al, FLG_CH3_HAS_REACHED_TERMINAL_COUNT  ; ... for channel 3 terminal count
     jz      SHORT .TransferNextDmaBlock ; If not set, get more bytes
-    pop     cx                          ; get back requested bytes
-%endif ; Fast DMA code
-
-    ; Update physical address in ES:DI - since IO might need several calls through this function either from here
-    ; if crossing a physical page boundary, and from IdeTransfer.asm if requested sectors was > PIOVARS.wSectorsInBlock
-    mov     ax, es                      ; copy physical page address to ax
-    add     di, cx                      ; add requested bytes to di
-    adc     al, 0                       ; and increment physical page address, if required
-    mov     es, ax                      ; and save it back in es
+%endif
 
     ret