Merge pull request #1711 from ghaerr/2880

[kernel] Fix to allow booting 2.88M floppy on dosbox

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

@@ -13,23 +13,30 @@
 #include <linuxmt/kdev_t.h>
 #include <linuxmt/debug.h>
 #include <arch/system.h>
+#include "bioshd.h"
 
 #define RESET_DISK_CHG  0       /* =1 to reset BIOS on drive change fixes QEMU retry */
 
-/* FIXME semi-copied from bioshd.c */
-#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*/
+/*
+ * Indices for fd_types array. Note these match the value returned
+ * by the BIOS in BL less 1, for INT 13h AH=8 (Get Disk Parms) for IBM PC.
+ */
+#define FD360           0
+#define FD1200          1
+#define FD720           2
+#define FD1440          3
+#define FD2880          4       /* QEMU returns 5 */
+#define FD2880_DUP      5       /* Dosbox returns 6 */
+#define FD1232          6       /* PC/98 only, not returned */
 
 struct drive_infot fd_types[] = {   /* AT/PS2 BIOS reported floppy formats*/
-    {40,  9, 2, 512, 0},
-    {80, 15, 2, 512, 1},
-    {80,  9, 2, 512, 2},
-    {80, 18, 2, 512, 3},
-    {80, 36, 2, 512, 4},
-#ifdef CONFIG_ARCH_PC98
-    {77,  8, 2, 1024,5},
-#endif
+    {40,  9, 2, 512, 0},            /* 360k */
+    {80, 15, 2, 512, 1},            /* 1.2M */
+    {80,  9, 2, 512, 2},            /* 720k */
+    {80, 18, 2, 512, 3},            /* 1.4M */
+    {80, 36, 2, 512, 5},            /* 2.88M */
+    {80, 36, 2, 512, 6},            /* 2.88M */
+    {77,  8, 2, 1024,7},            /* 1.232M PC/98 only */
 };
 
 /* BIOS drive mappings */
@@ -218,57 +225,46 @@ int INITPROC bios_gethdinfo(struct drive_infot *drivep) {
 #endif
 
 #ifdef CONFIG_BLK_DEV_BFD_HARD
-/* hard-coded floppy configuration*/
 int INITPROC bios_getfdinfo(struct drive_infot *drivep)
 {
-/* Set this to match your system. Currently it's set to a two drive system:
+/*
+ * Hard-coded floppy configuration
+ * Set below to match your system. For IBM PC, it's set to a two drive system:
  *
  *              720KB as /dev/fd0
  *      and     720KB as /dev/fd1
  *
- * ndrives is number of drives in your system (either 0, 1 or 2)
- */
-
-    int ndrives = MAXDRIVES;
-
-/* drive_info[] should be set *only* for existing drives;
- * comment out drive_info lines if you don't need them
- * (e.g. you have less than 2 drives)
- *
- * Enter type 4 in fd_types' brackets for unknown drive type
- * Otherwise use floppy drive type table below:
- *
- *      Type    Format
- *      ~~~~    ~~~~~~
+ * Drive Type   Format
+ *      ~~~~~   ~~~~~~
  *        0     360 KB
  *        1     1.2 MB
  *        2     720 KB
  *        3     1.44 MB
- *        4     2.88 MB or Unknown
- *        5     1.232 MB (PC98 1K sectors)
- *
- * Warning: drive will be reported as 2880 KB at bootup if you've set it
- * as unknown (4). Floppy probe will detect correct floppy format at each
- * change so don't bother with that
+ *        4     2.88 MB (QEMU)
+ *        5     2.88 MB (Dosbox)
+ *        6     1.232 MB (PC/98 1K sectors)
+ * ndrives is number of drives in your system (either 0, 1 or 2)
  */
 
+    int ndrives = FD_DRIVES;
+
 #ifdef CONFIG_ARCH_PC98
 #if defined(CONFIG_IMG_FD1232)
-    drivep[0] = fd_types[5];
-    drivep[1] = fd_types[5];
-    drivep[2] = fd_types[5];
-    drivep[3] = fd_types[5];
-#elif defined(CONFIG_IMG_FD1440)
-    drivep[0] = fd_types[3];
-    drivep[1] = fd_types[3];
-    drivep[2] = fd_types[3];
-    drivep[3] = fd_types[3];
+    drivep[0] = fd_types[FD1232];
+    drivep[1] = fd_types[FD1232];
+    drivep[2] = fd_types[FD1232];
+    drivep[3] = fd_types[FD1232];
+#else
+    drivep[0] = fd_types[FD1440];
+    drivep[1] = fd_types[FD1440];
+    drivep[2] = fd_types[FD1440];
+    drivep[3] = fd_types[FD1440];
 #endif
 #endif
 
 #ifdef CONFIG_ARCH_IBMPC
-    drivep[0] = fd_types[2];        /*  /dev/fd0    */
-    drivep[1] = fd_types[2];        /*  /dev/fd1    */
+    drivep[0] = fd_types[FD720];
+    drivep[1] = fd_types[FD720];
 #endif
 
     return ndrives;
@@ -296,10 +292,10 @@ int INITPROC bios_getfdinfo(struct drive_infot *drivep)
         if (peekb(0x55C,0) & (1 << drive)) {
 #ifdef CONFIG_IMG_FD1232
             bios_drive_map[DRIVE_FD0 + drive] = drive + 0x90;
-            *drivep = fd_types[5];
+            *drivep = fd_types[FD1232];
 #else
             bios_drive_map[DRIVE_FD0 + drive] = drive + 0x30;
-            *drivep = fd_types[3];
+            *drivep = fd_types[FD1440];
 #endif
             ndrives++;  /* floppy drive count*/
             drivep++;
@@ -315,7 +311,7 @@ int INITPROC bios_getfdinfo(struct drive_infot *drivep)
         if (!drives && ndrives) {       /* handle Toshiba T1100 BIOS returning 0 drives */
             for (drive = 0; drive < ndrives; drive++) {
                 printk("fd%d: default 720k\n", drive);
-                *drivep++ = fd_types[2];
+                *drivep++ = fd_types[FD720];
             }
             return ndrives;
         } else ndrives = drives;
@@ -331,10 +327,10 @@ int INITPROC bios_getfdinfo(struct drive_infot *drivep)
         BD_AX = BIOSHD_DRIVE_PARMS;
         BD_DX = drive;
         BD_ES = BD_DI = BD_SI = 0;      /* guard against BIOS bugs*/
-        if (!call_bios(&bdt))           /* returns drive type in BL*/
+        if (!call_bios(&bdt)) {         /* returns drive type in BL*/
             *drivep = fd_types[(BD_BX & 0xFF) - 1];
-        else {
-            int type = (sys_caps & CAP_PC_AT) ? 3 : 0;
+        } else {
+            int type = (sys_caps & CAP_PC_AT) ? FD1440 : FD360;
             *drivep = fd_types[type];
             printk("fd%d: default %s\n", drive, type? "1440k": "360k");
         }
@@ -389,9 +385,9 @@ void bios_switch_device98(int target, unsigned int device, struct drive_infot *d
     bios_drive_map[target + DRIVE_FD0] =
         (device | (bios_drive_map[target + DRIVE_FD0] & 0x0F));
     if (device == 0x30)
-        *drivep = fd_types[3];  /* 1.44 MB */
+        *drivep = fd_types[FD1440];
     else if (device == 0x90)
-        *drivep = fd_types[5];  /* 1.232 MB */
+        *drivep = fd_types[FD1232];
 }
 #endif
 

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

@@ -53,6 +53,7 @@
 #include <arch/system.h>
 #include <arch/irq.h>
 #include <arch/ports.h>
+#include "bioshd.h"
 
 #define PER_DRIVE_INFO  1       /* =1 for per-line display of drive info at init */
 #define DEBUG_PROBE     0       /* =1 to display more floppy probing information */
@@ -61,21 +62,6 @@
 //#define IODELAY       5       /* times 10ms, emulated delay for floppy on QEMU */
 #define MAX_ERRS        5       /* maximum sector read/write error retries */
 
-/* the following must match with /dev minor numbering scheme*/
-#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*/
-
-#define HD_DRIVES       4       /* max hard drives */
-#ifdef CONFIG_ARCH_PC98
-#define FD_DRIVES       4
-#else
-#define FD_DRIVES       2       /* max floppy drives */
-#endif
-#define NUM_DRIVES      (HD_DRIVES+FD_DRIVES) /* max number of drives (<=256/NUM_MINOR) */
-
 #define MAJOR_NR        BIOSHD_MAJOR
 #define BIOSDISK
 #include "blk.h"
@@ -378,7 +364,7 @@ void INITPROC bioshd_init(void)
     /* FIXME perhaps remove for speed on floppy boot*/
     outb_p(0x0C, FDC_DOR);      /* FD motors off, enable IRQ and DMA*/
 
-#ifdef CONFIG_BLK_DEV_BFD
+#if defined(CONFIG_BLK_DEV_BFD) || defined(CONFIG_BLK_DEV_BFD_HARD)
     fd_count = bios_getfdinfo(&drive_info[DRIVE_FD0]);
 #endif
 #ifdef CONFIG_BLK_DEV_BHD

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

@@ -0,0 +1,19 @@
+#ifndef _BIOSHD_H
+#define _BIOSHD_H
+
+/* the following must match with /dev minor numbering scheme*/
+#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*/
+
+#define HD_DRIVES       4       /* max hard drives */
+#ifdef CONFIG_ARCH_PC98
+#define FD_DRIVES       4
+#else
+#define FD_DRIVES       2       /* max floppy drives */
+#endif
+#define NUM_DRIVES      (HD_DRIVES+FD_DRIVES) /* max number of drives (<=256/NUM_MINOR) */
+
+#endif

elks/kernel/sched.c

@@ -71,7 +71,7 @@ void schedule(void)
     prev = current;
 
 #ifdef CHECK_SCHED
-    if (intr_count > 0) {
+    if (intr_count) {
         /* Taking a timer IRQ during another IRQ or while in kernel space is
          * quite legal. We just dont switch then */
          panic("SCHED: schedule() called from interrupt, intr_count %d", intr_count);