Changeset 445 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm

Timestamp:

Aug 29, 2012, 12:59:23 PM (12 years ago)

Author:

krille_n_@…

google:author:

krille_n_@hotmail.com

Message:

Changes:

• A speed optimization to the eSHL_IM macro for 386 and higher. This change breaks emulation in the sense that the macro will fail when given a memory operand as the first parameter.
• Memory_SumCXbytesFromESSItoAL now returns with the zero flag set/cleared according to the result.
• Unrolled all the 8 bit READ transfer loops to do 16 bytes per iteration. Added a new macro (UNROLL_SECTORS_IN_CX_TO_OWORDS) as part of it. Size wise this is expensive but I think it should be worth the ROM space. The WRITE transfer loops were left as is since writes are rare anyway (<10% of all disk I/O IIRC).
• Minor optimizations and fixes here and there.

File:

• trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm (modified) (5 diffs)

trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/AtaGeometry.asm

@@ -4 +4 @@
 ;
 ;                   These algorithms are taken from: http://www.mossywell.com/boot-sequence
-;                   Take a look at it for more detailed information.        
+;                   Take a look at it for more detailed information.
 ;
 ;                   This file is shared with BIOS Drive Information Tool.
 
 ;
-; XTIDE Universal BIOS and Associated Tools 
+; XTIDE Universal BIOS and Associated Tools
 ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team.
 ;
@@ -16 +16 @@
 ; the Free Software Foundation; either version 2 of the License, or
 ; (at your option) any later version.
-; 
+;
 ; This program is distributed in the hope that it will be useful,
 ; but WITHOUT ANY WARRANTY; without even the implied warranty of
 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-; GNU General Public License for more details.      
+; GNU General Public License for more details.
 ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 ;
-        
+
 ; Section containing code
 SECTION .text
@@ -33 +33 @@
 ;       ES:SI:  Ptr to 512-byte ATA information read from the drive
 ;   Returns:
-;       BX:DX:AX:   48-bit sectohr count
+;       BX:DX:AX:   48-bit sector count
 ;       CL:         FLGL_DPT_LBA48 if LBA48 supported
 ;                   Zero if only LBA28 is supported
@@ -239 +239 @@
     jbe     SHORT ReturnLCHSinAXBLBH
     shr     ax, 1       ; Halve cylinders
-    shl     bl, 1       ; Double heads
+    eSHL_IM bl, 1       ; Double heads
     inc     cx          ; Increment bit shift count
     mov     dl, TRANSLATEMODE_LARGE
@@ -300 +300 @@
     cmp     ax, cx
     jbe     SHORT .NumberOfHeadsNowInCX
-    shl     cx, 1                       ; Double number of heads
-    test    ch, ch                      ; Reached 256 heads?
-    jz      SHORT .CompareNextValidNumberOfHeads
-    dec     cx                          ;  If so, limit heads to 255
+    eSHL_IM cl, 1                       ; Double number of heads
+    jnz     SHORT .CompareNextValidNumberOfHeads    ; Reached 256 heads?
+    dec     cl                          ;  If so, limit heads to 255
 .NumberOfHeadsNowInCX:
     mov     bx, cx                      ; Number of heads are returned in BL