No subject

The current esp code will perform partial reads on devices with sector sizes 
> 512. The attached patch makes it read the whole sector from the device, and
uses the additional if multiple blocks are requested.

I'm not sure if the old behavior is technically wrong, but it confused me when
debugging the qemu device emulation :-)

Paul



Modified: openbios-devel/drivers/esp.c
===================================================================
--- openbios-devel/drivers/esp.c	2006-09-20 20:12:04 UTC (rev 86)
+++ openbios-devel/drivers/esp.c	2006-10-10 17:43:11 UTC (rev 87)
@@ -149,13 +149,12 @@
         return 0; // OK
 }
 
-// offset is multiple of 512, len in bytes
+// offset is in sectors
 static int
-ob_sd_read_sectors(esp_private_t *esp, sd_private_t *sd, int offset, void *dest,
-                   short len, short sect_offset)
+ob_sd_read_sector(esp_private_t *esp, sd_private_t *sd, int offset)
 {
-    DPRINTF("ob_sd_read_sectors id %d %lx sector=%d len=%d soff %d\n",
-	     sd->id, (unsigned long)dest, offset, len, sect_offset);
+    DPRINTF("ob_sd_read_sector id %d %lx sector=%d\n",
+            sd->id, (unsigned long)dest, offset);
 
     // Setup command = Read(10)
     memset(esp->buffer, 0, 10);
@@ -167,14 +166,12 @@
     esp->buffer[5] = (offset >> 8) & 0xff;
     esp->buffer[6] = offset & 0xff;
 
-    esp->buffer[8] = (len >> 8) & 0xff;
-    esp->buffer[9] = len & 0xff;
+    esp->buffer[8] = 0;
+    esp->buffer[9] = 1;
 
-    if (do_command(esp, sd, 10, len * 512 + sect_offset))
+    if (do_command(esp, sd, 10, sd->bs))
         return 0;
 
-    memcpy(dest, esp->buffer + sect_offset, len * 512);
-
     return 0;
 }
 
@@ -249,13 +246,17 @@
         sect_offset = blk / spb;
         pos = (blk - sect_offset * spb) * 512;
 
-        if (ob_sd_read_sectors(global_esp, *sd, sect_offset, dest, 1, pos)) {
+        if (ob_sd_read_sector(global_esp, *sd, sect_offset)) {
             DPRINTF("ob_sd_read_blocks: error\n");
             RET(0);
         }
-        dest += 512;
-        n--;
-        blk++;
+        while (n && pos < spb * 512) {
+            memcpy(dest, global_esp->buffer + pos, 512);
+            pos += 512;
+            dest += 512;
+            n--;
+            blk++;
+        }
     }
     PUSH(cnt);
 }