[kernel] Enhancements for multiple ROM configuration testing/support

elks/arch/i86/boot/setup.S

@@ -220,6 +220,16 @@ start_os:
 	mov	$INITSEG,%ax	// DS = setup data segment
 	mov	%ax,%ds
 
+#ifdef CONFIG_ROMCODE
+	mov	%ax,%es		// clear setup data segment
+	xor	%di,%di
+	xor	%ax,%ax
+	mov	$256,%cx
+	cld
+	rep
+	stosw
+#endif
+
 #ifdef CONFIG_HW_KEYBOARD_BIOS
 	mov	$0x0305,%ax	// set the keyboard repeat rate to the max
 	xor	%bx,%bx

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

@@ -182,7 +182,7 @@ static unsigned short int INITPROC bioshd_gethdinfo(void) {
 		drivep->heads, drivep->sectors);
 	}
 #ifdef CONFIG_IDE_PROBE
-	if (arch_cpu > 5) {	/* Do this only if AT or higher */
+	if (sys_caps & CAP_HD_IDE) {		/* Normally PC/AT or higher */
 	    if (!get_ide_data(drive, drivep)) {	/* get CHS from the drive itself */
 		/* sanity checks already done, accepting data */
 		printk("bioshd: hd%c  IDE CHS %d,%d,%d\n", 'a'+drive, drivep->cylinders,
@@ -242,18 +242,19 @@ static unsigned short int INITPROC bioshd_getfdinfo(void)
 {
     register struct drive_infot *drivep = &drive_info[DRIVE_FD0];
     int drive, ndrives = 0;
-    unsigned char equip_flags;
 
+#ifndef CONFIG_ROMCODE
     /*
      * The INT 13h floppy query will fail on IBM XT v1 BIOS and earlier,
      * so default to # drives from the BIOS data area at 0x040:0x0010 (INT 11h).
      */
-    equip_flags = peekb(0x10, 0x40);
+    unsigned char equip_flags = peekb(0x10, 0x40);
     if (equip_flags & 0x01)
 	ndrives = (equip_flags >> 6) + 1;
+#endif
 
-    /* Use INT 13h function 08h only if AT or higher*/
-    if (arch_cpu > 5) {
+    /* Use INT 13h function 08h normally if PC/AT or higher*/
+    if (sys_caps & CAP_DRIVE_PARMS) {
 	BD_AX = BIOSHD_DRIVE_PARMS;
 	BD_DX = 0;			/* query floppies only*/
 	BD_ES = BD_DI = BD_SI = 0;	/* guard against BIOS bugs*/
@@ -269,9 +270,9 @@ static unsigned short int INITPROC bioshd_getfdinfo(void)
 	 * If type cannot be determined using BIOSHD_DRIVE_PARMS,
 	 * set drive type to 1.4MM on AT systems, and 360K for XT.
 	 */
-	*drivep = fd_types[arch_cpu > 5 ? 3 : 0];
+	*drivep = fd_types[(sys_caps & CAP_PC_AT) ? 3 : 0];
 
-	if (arch_cpu > 5) {
+	if (sys_caps & CAP_DRIVE_PARMS) {
 	    BD_AX = BIOSHD_DRIVE_PARMS;
 	    BD_DX = drive;
 	    BD_ES = BD_DI = BD_SI = 0;	/* guard against BIOS bugs*/
@@ -547,7 +548,7 @@ int INITPROC bioshd_init(void)
 #endif
 #ifdef CONFIG_BLK_DEV_BHD
     _hd_count = bioshd_gethdinfo();
-    if (arch_cpu > 5) {		/* PC-AT or greater */
+    if (sys_caps & CAP_PC_AT) {	/* PC/AT or greater */
 	enable_irq(HD_IRQ);	/* AT ST506 */
 	enable_irq(15);		/* AHA1542 */
     }

elks/arch/i86/drivers/char/xt_key.c

@@ -420,7 +420,7 @@ static void set_leds(void)
 {
     unsigned char leds;
 
-    if (arch_cpu <= 5) return;	/* PC/XT doesn't have LEDs */
+    if (!(sys_caps & CAP_KBD_LEDS)) return;	/* PC/XT doesn't have LEDs */
 
     kb_wait();			/* wait for buffer empty  */
     outb_p(LED_CODE, KEYBD);	/* prepare keyboard to accept LED values */

elks/arch/i86/kernel/irq.c

@@ -89,9 +89,9 @@ void enable_irq(unsigned int irq)
 
 static int remap_irq(int irq)
 {
-    if (((unsigned int)irq > 15) || ((irq > 7) && (arch_cpu < 6)))
+    if ((unsigned int)irq > 15 || (irq > 7 && !(sys_caps & CAP_IRQ8TO15)))
 	return -EINVAL;
-    if (irq == 2 && arch_cpu > 5)
+    if (irq == 2 && (sys_caps & CAP_IRQ2MAP9))
 	irq = 9;			/* Map IRQ 9/2 over */
     return irq;
 }
@@ -219,15 +219,12 @@ void INITPROC irq_init(void)
 	panic("Unable to get timer");
 
     /* Re-start the timer only after irq is set */
-
     enable_timer_tick();
 
-#ifndef CONFIG_ARCH_SIBO
-    if (arch_cpu > 5) {		/* PC-AT or greater */
+    if (sys_caps & CAP_IRQ2MAP9) {	/* PC/AT or greater */
 	save_flags(flags);
 	clr_irq();
 	enable_irq(2);		/* Cascade slave PIC */
 	restore_flags(flags);
     }
-#endif
 }

elks/arch/i86/kernel/system.c

@@ -10,7 +10,7 @@
 #include <arch/segment.h>
 
 
-byte_t arch_cpu;  // processor number (from setup data)
+byte_t sys_caps;		/* system capabilities bits */
 
 #ifdef CONFIG_ARCH_SIBO
 extern long int basmem;
@@ -19,13 +19,10 @@ extern long int basmem;
 void INITPROC setup_arch(seg_t *start, seg_t *end)
 {
 #ifdef CONFIG_COMPAQ_FAST
-
 /*
  *	Switch COMPAQ Deskpro to high speed
  */
-
     outb_p(1,0xcf);
-
 #endif
 
 /*
@@ -61,8 +58,13 @@ void INITPROC setup_arch(seg_t *start, seg_t *end)
 	/* Misc */
 	ROOT_DEV = setupw(0x1fc);
 
-	arch_cpu = setupb(0x20);
-
+#ifdef SYS_CAPS
+	sys_caps = SYS_CAPS;	/* custom system capabilities */
+#else
+	byte_t arch_cpu = setupb(0x20);
+	if (arch_cpu > 5)		/* IBM PC/AT capabilities */
+		sys_caps = CAP_ALL;
+#endif
 }
 
 /* Stubs for functions needed elsewhere */

elks/arch/i86/mm/init.c

@@ -53,7 +53,7 @@ void INITPROC mm_stat(seg_t start, seg_t end)
 	*cp++ = setupb(i++);
 	if (i == 0x40) {
 	    printk("PC/%cT class machine, %s CPU, %uK base RAM",
-		    arch_cpu > 5 ? 'A' : 'X', proc_name, setupw(0x2a));
+		    (sys_caps & CAP_PC_AT) ? 'A' : 'X', proc_name, setupw(0x2a));
 	    cp = proc_name;
 	    i = 0x50;
 	}

elks/fs/super.c

@@ -47,12 +47,12 @@ extern struct file_system_type msdos_fs_type;
 
 static struct file_system_type *file_systems[] = {
 /* first filesystem is default filesystem for mount w/o -t parm*/
-#ifdef CONFIG_MINIX_FS
-	&minix_fs_type,
-#endif
 #ifdef CONFIG_ROMFS_FS
 	&romfs_fs_type,
 #endif
+#ifdef CONFIG_MINIX_FS
+	&minix_fs_type,
+#endif
 #ifdef CONFIG_FS_FAT
 	&msdos_fs_type,
 #endif

elks/include/arch/system.h

@@ -4,7 +4,7 @@
 #include <linuxmt/types.h>
 #include <linuxmt/init.h>
 
-extern byte_t arch_cpu;  // processor number (from setup data)
+extern byte_t sys_caps;		/* system capabilities bits*/
 
 extern void arch_setuptasks(void);
 extern void INITPROC setup_arch(seg_t *,seg_t *);

elks/include/linuxmt/config.h

@@ -4,15 +4,42 @@
 #include <autoconf.h>
 #include <linuxmt/major.h>
 
+/*
+ * System capabilities - configurable for ROM or custom installations.
+ * Normally, all capabilities will be set if arch_cpu > 5 (PC/AT),
+ * except when SYS_CAPS is defined for custom installations or emulations.
+ */
+#define CAP_PC_AT       0x01      /* PC/AT capabilities */
+#define CAP_DRIVE_PARMS	0x02      /* has INT 13h fn 8 drive parms */
+#define CAP_KBD_LEDS    0x04      /* has keyboard LEDs */
+#define CAP_HD_IDE      0x08      /* can do hard drive IDE probes */
+#define CAP_IRQ8TO15    CAP_PC_AT /* has IRQ 8 through 15 */
+#define CAP_IRQ2MAP9    CAP_PC_AT /* map IRQ 2 to 9 */
+#define CAP_ALL         0xFF      /* all capabilities if PC/AT only */
+
 /* Don't touch these, unless you really know what you are doing. */
 #define DEF_INITSEG	0x0100	/* setup data, for netboot use 0x5000 */
 #define DEF_SYSSEG	0x1000
 #define DEF_SETUPSEG	DEF_INITSEG + 0x20
 #define DEF_SYSSIZE	0x2F00
 
 #ifdef CONFIG_ROMCODE
+#define SYS_CAPS	(CAP_PC_AT|CAP_DRIVE_PARMS)
 #define SETUP_DATA	CONFIG_ROM_SETUP_DATA
 
+#ifdef CONFIG_BLK_DEV_BIOS    /* BIOS disk driver*/
+#define DMASEG		0x80  /* 0x400 bytes floppy sector buffer */
+#ifdef CONFIG_TRACK_CACHE     /* floppy track buffer in low mem */
+#define DMASEGSZ 0x2400       /* SECTOR_SIZE * 18 (9216) */
+#define KERNEL_DATA	0x2C0 /* kernel data segment */
+#else
+#define DMASEGSZ 0x040	      /* BLOCK_SIZE (1024) */
+#define KERNEL_DATA	0x0C0 /* kernel data segment */
+#endif
+#else
+#define KERNEL_DATA     0x80  /* kernel data segment */
+#endif
+
 #else
 #define SETUP_DATA	REL_INITSEG
 

emu86-disk.config

@@ -38,7 +38,7 @@ CONFIG_SMALL_KERNEL=y
 CONFIG_SYS_VERSION=y
 CONFIG_BOOTOPTS=y
 # CONFIG_STRACE is not set
-CONFIG_IDLE_HALT=y
+# CONFIG_IDLE_HALT is not set
 # CONFIG_ROMCODE is not set
 CONFIG_EXPERIMENTAL=y
 CONFIG_FARTEXT_KERNEL=y
@@ -84,7 +84,7 @@ CONFIG_BLK_DEV_BFD=y
 # CONFIG_BLK_DEV_BFD_HARD is not set
 CONFIG_TRACK_CACHE=y
 CONFIG_BLK_DEV_BHD=y
-# CONFIG_IDE_PROBE is not set
+CONFIG_IDE_PROBE=y
 # CONFIG_BLK_DEV_FD is not set
 # CONFIG_BLK_DEV_HD is not set
 # CONFIG_DMA is not set