Many fixes and improvements to the BIOS Extension ROM. (#33)

* Revert "Uploaded_2_9_2025"

This reverts commit ec79bbdbc9.

* Fixing DEBUG_IO builds.

* Make the IO port base a define.

* Fix CPU test to properly handle 808x vs V20.

* Improve timeout management logic.

* Improve SD Card initialization logic.

* Implement INT18h bootstrapping.

* Implementing a different test for processor type.

* Allow use with another fixed drive (eg: ESDI drive).

* Allow swapping driver ID between the BIOS disk and XTMax.

* Fix address of the ROM segment.

* Fixing missing STI at the top of the handler.

* Major rework of IO to use MOVSW.

* More code reorg and auto-detecting second drive.

* Update XTSD to use MOVSW.

* Add diagnostics program.

* Workaround for MS-DOS strange handling of interrupts.

* Use a lookup table for the memory map.

* Make the BootROM relocatable.

* Some more refactor of the Teensy code.

XTMax/Drivers/SDPP/DRIVER.C

@@ -365,14 +365,8 @@ PUBLIC void Initialize (rh_init_t far *rh)
   WORD brkadr, reboot[2];  int status, i;
 
   /* The version number is sneakily stored in the device header! */
-  cdprintf("SD Card driver V%c.%c for XTMax (%s)\n     based on SD pport device driver (C) 2014 by Dan Marks\n     based on TU58 by Robert Armstrong\n",
-    header.name[6], header.name[7],
-#ifdef USE186
-    "80186+"
-#else
-    "8086"
-#endif
-    );
+  cdprintf("SD Card driver V%c.%c for XTMax\n     based on SD pport device driver (C) 2014 by Dan Marks\n     based on TU58 by Robert Armstrong\n",
+    header.name[6], header.name[7]);
 
   /* Parse the options from the CONFIG.SYS file, if any... */
   if (!parse_options((char far *) rh->bpbtbl)) {

XTMax/Drivers/SDPP/HEADER.ASM

@@ -129,7 +129,7 @@ _header  DD -1    ; link to the next device
    DW DGROUP:STRATEGY   ; address of the strategy routine
    DW DGROUP:INTERRUPT;  "     "   "  interrupt   "
    DB 1     ; number of drives
-   DB 'SDCDv12'   ; DOS doesn't really use these bytes
+   DB 'SDCDv13'   ; DOS doesn't really use these bytes
 
 ;   The geometry (sectors/track, tracks/cylinder) defined in the BPB is rather
 ; arbitrary in the case of the TU58, but there are things to watch out for.

XTMax/Drivers/SDPP/MAKEFILE

@@ -5,7 +5,7 @@ ASM=tasm -mx
 
 DEPS=cprint.c driver.c sd.c sdmm.c cprint.h diskio.h driver.h integer.h sd.h standard.h 
 
-all: xtsd.sys xtsd186.sys
+all: xtsd.sys
 
 .asm.obj:
    $(ASM) $*
@@ -17,13 +17,6 @@ xtsd.sys: header.obj $(DEPS)
    $(CC) driver.c
    tlink -t -m -s -n header cprint sd sdmm driver, $@
 
-xtsd186.sys: header.obj $(DEPS)
-   $(CC) -1 -DUSE186 cprint.c
-   $(CC) -1 -DUSE186 sd.c
-   $(CC) -1 -DUSE186 sdmm.c
-   $(CC) -1 -DUSE186 driver.c
-   tlink -t -m -s -n header cprint sd sdmm driver, $@
-
 clean:
    del *.obj
    del *.map

XTMax/Drivers/SDPP/SDMM.C

@@ -27,8 +27,9 @@
 /* Platform dependent macros and functions needed to be modified           */
 /*-------------------------------------------------------------------------*/
 
+DWORD VIRT_BUFFER=0xCE000000+2048;
 WORD DATAPORT=0x280;
-WORD CONTROLPORT=0x282;
+WORD CONTROLPORT=0x280+1;
 
 #if 1
 #define TOUTCHR(x)
@@ -177,30 +178,17 @@ void xmit_mmc (
    // NOTE: Callers always use buffer sizes multiple of two.
    bc >>= 1;
 
-#ifndef USE186
    _asm {
       mov   cx,bc
-      mov   dx,DATAPORT
       push  ds
+      push  es
+      les   di,VIRT_BUFFER
       lds   si,dword ptr buff
-   }
-   repeat:
-   _asm {
-      lodsw
-      out   dx, ax
-      loop  repeat
+      cld
+      rep   movsw
+      pop   es
       pop   ds
    }
-#else
-   _asm {
-      mov   cx,bc
-      mov   dx,DATAPORT
-      push  ds
-      lds   si,dword ptr buff
-      rep   outsw
-      pop   ds
-   }
-#endif
 }
 
 
@@ -218,30 +206,17 @@ void rcvr_mmc (
    // NOTE: Callers always use buffer sizes multiple of two.
    bc >>= 1;
 
-#ifndef USE186
    _asm {
       mov   cx,bc
-      mov   dx,DATAPORT
+      push  ds
       push  es
       les   di,dword ptr buff
-   }
-   repeat:
-   _asm {
-      in    ax, dx
-      stosw
-      loop  repeat
+      lds   si,VIRT_BUFFER
+      cld
+      rep   movsw
       pop   es
+      pop   ds
    }
-#else
-   _asm {
-      mov   cx,bc
-      mov   dx,DATAPORT
-      push  es
-      les   di,dword ptr buff
-      rep   insw
-      pop   es
-   }
-#endif
 }
 
 /*-----------------------------------------------------------------------*/
@@ -254,14 +229,13 @@ int wait_ready (void)   /* 1:OK, 0:Timeout */
    BYTE d;
    UINT tmr;
 
-
-   for (tmr = 5000; tmr; tmr--) {   /* Wait for ready in timeout of 500ms */
+   outp(DATAPORT+7, 50);
+   do {   /* Wait for ready in timeout of 500ms */
       d = inp(DATAPORT);
       if (d == 0xFF) break;
-      dly_us(100);
-   }
+   } while(!inp(DATAPORT+7));
 
-   return tmr ? 1 : 0;
+   return d == 0xFF;
 }
 
 
@@ -310,11 +284,11 @@ int rcvr_datablock ( /* 1:OK, 0:Failed */
    UINT tmr;
 
 
-   for (tmr = 1000; tmr; tmr--) {   /* Wait for data packet in timeout of 100ms */
+   outp(DATAPORT+7, 10);
+   do {   /* Wait for data packet in timeout of 100ms */
       d = inp(DATAPORT);
       if (d != 0xFF) break;
-      dly_us(100);
-   }
+   } while(!inp(DATAPORT+7));
    if (d != 0xFE) {
     return 0;      /* If not valid data token, return with error */
    }