Don't invalidate cache on writes unless operating on current cached d…

…rive

Set TRACKSEGSZ 0 unless CONFIG_TRACK_CACHE or DF
Indentation cleanup

elks/arch/i86/drivers/block/bioshd.c

@@ -560,25 +560,25 @@ static int BFPROC do_readwrite(struct drive_infot *drivep, sector_t start, char
                         drive, start, this_pass);
 
 #pragma GCC diagnostic ignored "-Wshift-count-overflow"
-        usedmaseg = seg >> 16; /* will be nonzero only if XMS configured and XMS buffer */
-        if (!usedmaseg) {
-            /* check for 64k I/O overlap */
-            physaddr = (seg << 4) + (unsigned int)buf;
-            end = this_pass * drivep->sector_size - 1;
-            usedmaseg = (physaddr + end < physaddr);
-            debug_blk("bioshd: %p:%p = %p count %d wrap %d\n",
-                (unsigned int)seg, buf, physaddr, this_pass, usedmaseg);
-        }
-        if (usedmaseg) {
-            segment = DMASEG;           /* if xms buffer use DMASEG*/
-            offset = 0;
-            if (cmd == WRITE)           /* copy xms buffer down before write*/
-                xms_fmemcpyw(0, DMASEG, buf, seg, this_pass*(drivep->sector_size >> 1));
-            //set_cache_invalid();      /* don't invalidate cache - not shared */
-        } else {
-            segment = (seg_t)seg;
-            offset = (unsigned) buf;
-        }
+    usedmaseg = seg >> 16; /* will be nonzero only if XMS configured and XMS buffer */
+    if (!usedmaseg) {
+        /* check for 64k I/O overlap */
+        physaddr = (seg << 4) + (unsigned int)buf;
+        end = this_pass * drivep->sector_size - 1;
+        usedmaseg = (physaddr + end < physaddr);
+        debug_blk("bioshd: %p:%p = %p count %d wrap %d\n",
+            (unsigned int)seg, buf, physaddr, this_pass, usedmaseg);
+    }
+    if (usedmaseg) {
+        segment = DMASEG;           /* if xms buffer use DMASEG*/
+        offset = 0;
+        if (cmd == WRITE)           /* copy xms buffer down before write*/
+            xms_fmemcpyw(0, DMASEG, buf, seg, this_pass*(drivep->sector_size >> 1));
+        //set_cache_invalid();      /* don't invalidate cache - not shared */
+    } else {
+        segment = (seg_t)seg;
+        offset = (unsigned) buf;
+    }
     errs = MAX_ERRS;        /* BIOS disk reads should be retried at least five times */
     do {
         debug_cache("%s%s%d CHS %d/%d/%d count %d\n",
@@ -598,15 +598,16 @@ static int BFPROC do_readwrite(struct drive_infot *drivep, sector_t start, char
     } while (error && --errs);      /* On error, retry up to MAX_ERRS times */
     last_drive = drivep;
 
+    if (cmd == WRITE && drivep == cache_drive)
+        set_cache_invalid();        /* cache not updated on write so invalidate */
+
     if (error) return 0;            /* error message in blk.h */
 
     if (usedmaseg) {
         if (cmd == READ)            /* copy DMASEG up to xms*/
             xms_fmemcpyw(buf, seg, 0, DMASEG, this_pass*(drivep->sector_size >> 1));
         //set_cache_invalid();      /* don't invalidate cache - not shared */
     }
-    if (cmd == WRITE && drivep == cache_drive)
-        set_cache_invalid();        /* cache isn't updated on writes */
     return this_pass;
 }
 
@@ -689,8 +690,8 @@ static int BFPROC do_cache_read(struct drive_infot *drivep, sector_t start, char
         do_readtrack(drivep, start);                /* read whole track*/
         if (cache_valid(drivep, start, buf, seg))   /* try cache again*/
             return 1;
+        //set_cache_invalid();          /* old code invalidated cache on failure */
     }
-    set_cache_invalid();
     return 0;
 }
 #endif

elks/include/linuxmt/config.h

@@ -115,17 +115,21 @@
  * outside its track cache; thus the complicated defines below.
  */
 
-#if defined(CONFIG_BLK_DEV_BFD) || defined(CONFIG_BLK_DEV_BHD)
+#if defined(CONFIG_BLK_DEV_BFD) || defined(CONFIG_BLK_DEV_BHD)  /* BIOS driver */
 #define DMASEGSZ        0x0400      /* BLOCK_SIZE (1024) for external XMS/DMA buffer */
 #else
 #define DMASEGSZ        0           /* no external XMS/DMA buffer */
 #endif
 
 #if defined(CONFIG_BLK_DEV_BFD) || defined(CONFIG_BLK_DEV_BHD) || defined(CONFIG_BLK_FD)
 #ifdef CONFIG_TRACK_CACHE           /* floppy track buffer in low mem */
-#define TRACKSEGSZ      0x2400      /* SECTOR_SIZE * 18 (9216) */
+#   define TRACKSEGSZ      0x2400   /* SECTOR_SIZE * 18 (9216) */
 #else
-#define TRACKSEGSZ      0x0400      /* BLOCK_SIZE (1024) */
+#  ifdef CONFIG_BLK_FD
+#  define TRACKSEGSZ      0x0400    /* DF driver requires DMASEG internal to TRACKSEG */
+#  else
+#  define TRACKSEGSZ      0         /* no TRACKSEG buffer */
+#  endif
 #endif
 #define TRACKSEG        (DMASEG+(DMASEGSZ>>4))
 #define DMASEGEND       (DMASEG+(DMASEGSZ>>4)+(TRACKSEGSZ>>4))

emu86.sh

@@ -21,7 +21,7 @@ exec emu86 -w 0xe0000 -f image/rom-8088.bin -w 0x80000 -f image/romfs-8088.bin $
 # For ELKS Full ROM Configuration:
 # ELKS must be configured minimally with 'cp emu86-rom-full.config .config'
 # This adds MINIX/FAT filesytems with BIOS driver
-#exec emu86 -w 0xe0000 -f rom-8088.bin -w 0x80000 -f image/romfs.bin -I image/fd1440.img ${1+"$@"}
+#exec emu86 -w 0xe0000 -f image/rom-8088.bin -w 0x80000 -f image/romfs-8088.bin -I image/fd1440.img ${1+"$@"}
 
 # For ELKS disk image Configuration:
 # ELKS must be configured with 'cp emu86-disk.config .config'