Merge pull request #1710 from ghaerr/bioshd4

[kernel] Change bioshd minor numbering scheme to conserve kernel data size
ghaerr · Sep 11, 2023 · 18d1379 · 18d1379
2 parents 5eaea47 + 73b9630
commit 18d1379
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Showing 4 changed files with 23 additions and 24 deletions.
diff --git a/elks/arch/i86/drivers/block/bios.c b/elks/arch/i86/drivers/block/bios.c
@@ -17,8 +17,8 @@
 #define RESET_DISK_CHG  0       /* =1 to reset BIOS on drive change fixes QEMU retry */
 
 /* FIXME semi-copied from bioshd.c */
-#define MINOR_SHIFT     5       /* =log2(NUM_MINOR) shift to get drive num*/
-#define MAX_DRIVES      8       /* =256/NUM_MINOR*/
+#define MINOR_SHIFT     3       /* =log2(NUM_MINOR) shift to get drive num*/
+#define MAX_DRIVES      8       /* <=256/NUM_MINOR*/
 #define DRIVE_FD0       4       /* =MAX_DRIVES/2 first floppy drive*/
 
 struct drive_infot fd_types[] = {   /* AT/PS2 BIOS reported floppy formats*/

diff --git a/elks/arch/i86/drivers/block/bioshd.c b/elks/arch/i86/drivers/block/bioshd.c
@@ -62,9 +62,9 @@
 #define MAX_ERRS        5       /* maximum sector read/write error retries */
 
 /* the following must match with /dev minor numbering scheme*/
-#define NUM_MINOR       32      /* max minor devices per drive*/
-#define MINOR_SHIFT     5       /* =log2(NUM_MINOR) shift to get drive num*/
-#define MAX_DRIVES      8       /* =256/NUM_MINOR*/
+#define NUM_MINOR       8       /* max minor devices per drive*/
+#define MINOR_SHIFT     3       /* =log2(NUM_MINOR) shift to get drive num*/
+#define MAX_DRIVES      8       /* <=256/NUM_MINOR*/
 #define DRIVE_HD0       0
 #define DRIVE_FD0       4       /* =MAX_DRIVES/2 first floppy drive*/
 

diff --git a/elks/include/linuxmt/devnum.h b/elks/include/linuxmt/devnum.h
@@ -12,13 +12,13 @@
 
 /* block devices */
 #define DEV_HDA     MKDEV(BIOSHD_MAJOR, 0)
-#define DEV_HDB     MKDEV(BIOSHD_MAJOR, 32)
-#define DEV_HDC     MKDEV(BIOSHD_MAJOR, 64)
-#define DEV_HDD     MKDEV(BIOSHD_MAJOR, 96)
-#define DEV_FD0     MKDEV(BIOSHD_MAJOR, 128)
-#define DEV_FD1     MKDEV(BIOSHD_MAJOR, 160)
-#define DEV_FD2     MKDEV(BIOSHD_MAJOR, 192)
-#define DEV_FD3     MKDEV(BIOSHD_MAJOR, 224)
+#define DEV_HDB     MKDEV(BIOSHD_MAJOR, 8)
+#define DEV_HDC     MKDEV(BIOSHD_MAJOR, 16)
+#define DEV_HDD     MKDEV(BIOSHD_MAJOR, 24)
+#define DEV_FD0     MKDEV(BIOSHD_MAJOR, 32)
+#define DEV_FD1     MKDEV(BIOSHD_MAJOR, 40)
+#define DEV_FD2     MKDEV(BIOSHD_MAJOR, 48)
+#define DEV_FD3     MKDEV(BIOSHD_MAJOR, 56)
 #define DEV_ROM     MKDEV(ROMFLASH_MAJOR, 0)
 
 /* char devices */

diff --git a/image/Make.devices b/image/Make.devices
@@ -38,7 +38,7 @@ devices:
 
 ##############################################################################
 # BIOS devices, hard and floppy disks.
-# Limit to 4 primary partitions per disk (MBR).
+# Limit to 4 primary partitions and 3 extended per disk (MBR).
 
 	$(MKDEV) /dev/hda  b 3 0
 	$(MKDEV) /dev/hda1 b 3 1
@@ -48,17 +48,16 @@ devices:
 	$(MKDEV) /dev/hda5 b 3 5
 	$(MKDEV) /dev/hda6 b 3 6
 	$(MKDEV) /dev/hda7 b 3 7
-	$(MKDEV) /dev/hda8 b 3 8
-	$(MKDEV) /dev/hdb  b 3 32
-	$(MKDEV) /dev/hdb1 b 3 33
-	$(MKDEV) /dev/hdb2 b 3 34
-	$(MKDEV) /dev/hdb3 b 3 35
-	$(MKDEV) /dev/hdb4 b 3 36
-	$(MKDEV) /dev/hdc  b 3 64
-	$(MKDEV) /dev/hdc1 b 3 65
-	$(MKDEV) /dev/hdd  b 3 96
-	$(MKDEV) /dev/fd0  b 3 128
-	$(MKDEV) /dev/fd1  b 3 160
+	$(MKDEV) /dev/hdb  b 3 8
+	$(MKDEV) /dev/hdb1 b 3 9
+	$(MKDEV) /dev/hdb2 b 3 10
+	$(MKDEV) /dev/hdb3 b 3 11
+	$(MKDEV) /dev/hdb4 b 3 12
+	$(MKDEV) /dev/hdc  b 3 16
+	$(MKDEV) /dev/hdc1 b 3 17
+	$(MKDEV) /dev/hdd  b 3 24
+	$(MKDEV) /dev/fd0  b 3 32
+	$(MKDEV) /dev/fd1  b 3 40
 
 ##############################################################################
 # Pseudo-TTY master devices.