Import of Linus's Linux 1.1.68

1 files changed, 648 insertions, 0 deletions

diff --git a/init/main.c b/init/main.c
new file mode 100644
index 000000000..ceaabb60f
--- /dev/null
+++ b/init/main.c
@@ -0,0 +1,648 @@
+/*
+ *  linux/init/main.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <stdarg.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/head.h>
+#include <linux/unistd.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/fs.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/utsname.h>
+#include <linux/ioport.h>
+
+extern unsigned long * prof_buffer;
+extern unsigned long prof_len;
+extern char edata, end;
+extern char *linux_banner;
+asmlinkage void lcall7(void);
+struct desc_struct default_ldt;
+
+/*
+ * we need this inline - forking from kernel space will result
+ * in NO COPY ON WRITE (!!!), until an execve is executed. This
+ * is no problem, but for the stack. This is handled by not letting
+ * main() use the stack at all after fork(). Thus, no function
+ * calls - which means inline code for fork too, as otherwise we
+ * would use the stack upon exit from 'fork()'.
+ *
+ * Actually only pause and fork are needed inline, so that there
+ * won't be any messing with the stack from main(), but we define
+ * some others too.
+ */
+#define __NR__exit __NR_exit
+static inline _syscall0(int,idle)
+static inline _syscall0(int,fork)
+static inline _syscall0(int,pause)
+static inline _syscall0(int,setup)
+static inline _syscall0(int,sync)
+static inline _syscall0(pid_t,setsid)
+static inline _syscall3(int,write,int,fd,const char *,buf,off_t,count)
+static inline _syscall1(int,dup,int,fd)
+static inline _syscall3(int,execve,const char *,file,char **,argv,char **,envp)
+static inline _syscall3(int,open,const char *,file,int,flag,int,mode)
+static inline _syscall1(int,close,int,fd)
+static inline _syscall1(int,_exit,int,exitcode)
+static inline _syscall3(pid_t,waitpid,pid_t,pid,int *,wait_stat,int,options)
+
+static inline pid_t wait(int * wait_stat)
+{
+	return waitpid(-1,wait_stat,0);
+}
+
+static char printbuf[1024];
+
+extern int console_loglevel;
+
+extern char empty_zero_page[PAGE_SIZE];
+extern void init(void);
+extern void init_IRQ(void);
+extern void init_modules(void);
+extern long console_init(long, long);
+extern long kmalloc_init(long,long);
+extern long blk_dev_init(long,long);
+extern long chr_dev_init(long,long);
+extern void sock_init(void);
+extern long rd_init(long mem_start, int length);
+unsigned long net_dev_init(unsigned long, unsigned long);
+extern long bios32_init(long, long);
+
+extern void hd_setup(char *str, int *ints);
+extern void bmouse_setup(char *str, int *ints);
+extern void eth_setup(char *str, int *ints);
+extern void xd_setup(char *str, int *ints);
+extern void mcd_setup(char *str, int *ints);
+extern void st_setup(char *str, int *ints);
+extern void st0x_setup(char *str, int *ints);
+extern void tmc8xx_setup(char *str, int *ints);
+extern void t128_setup(char *str, int *ints);
+extern void pas16_setup(char *str, int *ints);
+extern void generic_NCR5380_setup(char *str, int *intr);
+extern void aha152x_setup(char *str, int *ints);
+extern void aha1542_setup(char *str, int *ints);
+extern void aha274x_setup(char *str, int *ints);
+extern void scsi_luns_setup(char *str, int *ints);
+extern void sound_setup(char *str, int *ints);
+#ifdef CONFIG_SBPCD
+extern void sbpcd_setup(char *str, int *ints);
+#endif CONFIG_SBPCD
+#ifdef CONFIG_CDU31A
+extern void cdu31a_setup(char *str, int *ints);
+#endif CONFIG_CDU31A
+void ramdisk_setup(char *str, int *ints);
+
+#ifdef CONFIG_SYSVIPC
+extern void ipc_init(void);
+#endif
+#ifdef CONFIG_SCSI
+extern unsigned long scsi_dev_init(unsigned long, unsigned long);
+#endif
+
+/*
+ * This is set up by the setup-routine at boot-time
+ */
+#define PARAM	empty_zero_page
+#define EXT_MEM_K (*(unsigned short *) (PARAM+2))
+#define DRIVE_INFO (*(struct drive_info_struct *) (PARAM+0x80))
+#define SCREEN_INFO (*(struct screen_info *) (PARAM+0))
+#define MOUNT_ROOT_RDONLY (*(unsigned short *) (PARAM+0x1F2))
+#define RAMDISK_SIZE (*(unsigned short *) (PARAM+0x1F8))
+#define ORIG_ROOT_DEV (*(unsigned short *) (PARAM+0x1FC))
+#define AUX_DEVICE_INFO (*(unsigned char *) (PARAM+0x1FF))
+
+/*
+ * Boot command-line arguments
+ */
+#define MAX_INIT_ARGS 8
+#define MAX_INIT_ENVS 8
+#define COMMAND_LINE ((char *) (PARAM+2048))
+#define COMMAND_LINE_SIZE 256
+
+extern void time_init(void);
+
+static unsigned long memory_start = 0;	/* After mem_init, stores the */
+					/* amount of free user memory */
+static unsigned long memory_end = 0;
+static unsigned long low_memory_start = 0;
+
+static char term[21];
+int rows, cols;
+
+static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
+static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", term, NULL, };
+
+static char * argv_rc[] = { "/bin/sh", NULL };
+static char * envp_rc[] = { "HOME=/", term, NULL };
+
+static char * argv[] = { "-/bin/sh",NULL };
+static char * envp[] = { "HOME=/usr/root", term, NULL };
+
+struct drive_info_struct { char dummy[32]; } drive_info;
+struct screen_info screen_info;
+
+unsigned char aux_device_present;
+int ramdisk_size;
+int root_mountflags = 0;
+
+static char fpu_error = 0;
+
+static char command_line[COMMAND_LINE_SIZE] = { 0, };
+
+char *get_options(char *str, int *ints)
+{
+	char *cur = str;
+	int i=1;
+
+	while (cur && isdigit(*cur) && i <= 10) {
+		ints[i++] = simple_strtoul(cur,NULL,0);
+		if ((cur = strchr(cur,',')) != NULL)
+			cur++;
+	}
+	ints[0] = i-1;
+	return(cur);
+}
+
+struct {
+	char *str;
+	void (*setup_func)(char *, int *);
+} bootsetups[] = {
+	{ "reserve=", reserve_setup },
+	{ "ramdisk=", ramdisk_setup },
+#ifdef CONFIG_INET
+	{ "ether=", eth_setup },
+#endif
+#ifdef CONFIG_SCSI
+	{ "max_scsi_luns=", scsi_luns_setup },
+#endif
+#ifdef CONFIG_BLK_DEV_HD
+	{ "hd=", hd_setup },
+#endif
+#ifdef CONFIG_CHR_DEV_ST
+	{ "st=", st_setup },
+#endif
+#ifdef CONFIG_BUSMOUSE
+	{ "bmouse=", bmouse_setup },
+#endif
+#ifdef CONFIG_SCSI_SEAGATE
+	{ "st0x=", st0x_setup },
+	{ "tmc8xx=", tmc8xx_setup },
+#endif
+#ifdef CONFIG_SCSI_T128
+	{ "t128=", t128_setup },
+#endif
+#ifdef CONFIG_SCSI_PAS16
+	{ "pas16=", pas16_setup },
+#endif
+#ifdef CONFIG_SCSI_GENERIC_NCR5380
+	{ "ncr5380=", generic_NCR5380_setup },
+#endif
+#ifdef CONFIG_SCSI_AHA152X
+        { "aha152x=", aha152x_setup},
+#endif
+#ifdef CONFIG_SCSI_AHA1542
+        { "aha1542=", aha1542_setup},
+#endif
+#ifdef CONFIG_SCSI_AHA274X
+        { "aha274x=", aha274x_setup},
+#endif
+#ifdef CONFIG_BLK_DEV_XD
+	{ "xd=", xd_setup },
+#endif
+#ifdef CONFIG_MCD
+	{ "mcd=", mcd_setup },
+#endif
+#ifdef CONFIG_SOUND
+	{ "sound=", sound_setup },
+#endif
+#ifdef CONFIG_SBPCD
+	{ "sbpcd=", sbpcd_setup },
+#endif CONFIG_SBPCD
+#ifdef CONFIG_CDU31A
+	{ "cdu31a=", cdu31a_setup },
+#endif CONFIG_CDU31A
+	{ 0, 0 }
+};
+
+void ramdisk_setup(char *str, int *ints)
+{
+   if (ints[0] > 0 && ints[1] >= 0)
+      ramdisk_size = ints[1];
+}
+
+static int checksetup(char *line)
+{
+	int i = 0;
+	int ints[11];
+
+	while (bootsetups[i].str) {
+		int n = strlen(bootsetups[i].str);
+		if (!strncmp(line,bootsetups[i].str,n)) {
+			bootsetups[i].setup_func(get_options(line+n,ints), ints);
+			return 1;
+		}
+		i++;
+	}
+	return 0;
+}
+
+unsigned long loops_per_sec = 1;
+
+static void calibrate_delay(void)
+{
+	int ticks;
+
+	printk("Calibrating delay loop.. ");
+	while (loops_per_sec <<= 1) {
+		/* wait for "start of" clock tick */
+		ticks = jiffies;
+		while (ticks == jiffies)
+			/* nothing */;
+		/* Go .. */
+		ticks = jiffies;
+		__delay(loops_per_sec);
+		ticks = jiffies - ticks;
+		if (ticks >= HZ) {
+			__asm__("mull %1 ; divl %2"
+				:"=a" (loops_per_sec)
+				:"d" (HZ),
+				 "r" (ticks),
+				 "0" (loops_per_sec)
+				:"dx");
+			printk("ok - %lu.%02lu BogoMips\n",
+				loops_per_sec/500000,
+				(loops_per_sec/5000) % 100);
+			return;
+		}
+	}
+	printk("failed\n");
+}
+
+
+/*
+ * This is a simple kernel command line parsing function: it parses
+ * the command line, and fills in the arguments/environment to init
+ * as appropriate. Any cmd-line option is taken to be an environment
+ * variable if it contains the character '='.
+ *
+ *
+ * This routine also checks for options meant for the kernel - currently
+ * only the "root=XXXX" option is recognized. These options are not given
+ * to init - they are for internal kernel use only.
+ */
+static void parse_options(char *line)
+{
+	char *next;
+	char *devnames[] = { "hda", "hdb", "sda", "sdb", "sdc", "sdd", "sde", "fd", "xda", "xdb", NULL };
+	int devnums[]    = { 0x300, 0x340, 0x800, 0x810, 0x820, 0x830, 0x840, 0x200, 0xD00, 0xD40, 0};
+	int args, envs;
+
+	if (!*line)
+		return;
+	args = 0;
+	envs = 1;	/* TERM is set to 'console' by default */
+	next = line;
+	while ((line = next) != NULL) {
+		if ((next = strchr(line,' ')) != NULL)
+			*next++ = 0;
+		/*
+		 * check for kernel options first..
+		 */
+		if (!strncmp(line,"root=",5)) {
+			int n;
+			line += 5;
+			if (strncmp(line,"/dev/",5)) {
+				ROOT_DEV = simple_strtoul(line,NULL,16);
+				continue;
+			}
+			line += 5;
+			for (n = 0 ; devnames[n] ; n++) {
+				int len = strlen(devnames[n]);
+				if (!strncmp(line,devnames[n],len)) {
+					ROOT_DEV = devnums[n]+simple_strtoul(line+len,NULL,0);
+					break;
+				}
+			}
+			continue;
+		}
+		if (!strcmp(line,"ro")) {
+			root_mountflags |= MS_RDONLY;
+			continue;
+		}
+		if (!strcmp(line,"rw")) {
+			root_mountflags &= ~MS_RDONLY;
+			continue;
+		}
+		if (!strcmp(line,"debug")) {
+			console_loglevel = 10;
+			continue;
+		}
+		if (!strcmp(line,"no-hlt")) {
+			hlt_works_ok = 0;
+			continue;
+		}
+		if (!strcmp(line,"no387")) {
+			hard_math = 0;
+			__asm__("movl %%cr0,%%eax\n\t"
+				"orl $0xE,%%eax\n\t"
+				"movl %%eax,%%cr0\n\t" : : : "ax");
+			continue;
+		}
+		if (checksetup(line))
+			continue;
+		/*
+		 * Then check if it's an environment variable or
+		 * an option.
+		 */
+		if (strchr(line,'=')) {
+			if (envs >= MAX_INIT_ENVS)
+				break;
+			envp_init[++envs] = line;
+		} else {
+			if (args >= MAX_INIT_ARGS)
+				break;
+			argv_init[++args] = line;
+		}
+	}
+	argv_init[args+1] = NULL;
+	envp_init[envs+1] = NULL;
+}
+
+static void copy_options(char * to, char * from)
+{
+	char c = ' ';
+	int len = 0;
+
+	for (;;) {
+		if (c == ' ' && *(unsigned long *)from == *(unsigned long *)"mem=")
+			memory_end = simple_strtoul(from+4, &from, 0);
+		c = *(from++);
+		if (!c)
+			break;
+		if (COMMAND_LINE_SIZE <= ++len)
+			break;
+		*(to++) = c;
+	}
+	*to = '\0';
+}
+
+static void copro_timeout(void)
+{
+	fpu_error = 1;
+	timer_table[COPRO_TIMER].expires = jiffies+100;
+	timer_active |= 1<<COPRO_TIMER;
+	printk("387 failed: trying to reset\n");
+	send_sig(SIGFPE, last_task_used_math, 1);
+	outb_p(0,0xf1);
+	outb_p(0,0xf0);
+}
+
+static void check_fpu(void)
+{
+	static double x = 4195835.0;
+	static double y = 3145727.0;
+	unsigned short control_word;
+	int i;
+
+	if (!hard_math) {
+#ifndef CONFIG_MATH_EMULATION
+		printk("No coprocessor found and no math emulation present.\n");
+		printk("Giving up.\n");
+		for (;;) ;
+#endif
+		return;
+	}
+	/*
+	 * check if exception 16 works correctly.. This is truly evil
+	 * code: it disables the high 8 interrupts to make sure that
+	 * the irq13 doesn't happen. But as this will lead to a lockup
+	 * if no exception16 arrives, it depends on the fact that the
+	 * high 8 interrupts will be re-enabled by the next timer tick.
+	 * So the irq13 will happen eventually, but the exception 16
+	 * should get there first..
+	 */
+	printk("Checking 386/387 coupling... ");
+	timer_table[COPRO_TIMER].expires = jiffies+50;
+	timer_table[COPRO_TIMER].fn = copro_timeout;
+	timer_active |= 1<<COPRO_TIMER;
+	__asm__("clts ; fninit ; fnstcw %0 ; fwait":"=m" (*&control_word));
+	control_word &= 0xffc0;
+	__asm__("fldcw %0 ; fwait": :"m" (*&control_word));
+	outb_p(inb_p(0x21) | (1 << 2), 0x21);
+	__asm__("fldz ; fld1 ; fdiv %st,%st(1) ; fwait");
+	timer_active &= ~(1<<COPRO_TIMER);
+	if (fpu_error)
+		return;
+	if (!ignore_irq13) {
+		printk("Ok, fpu using old IRQ13 error reporting\n");
+		return;
+	}
+	__asm__("fninit\n\t"
+		"fldl %1\n\t"
+		"fdivl %2\n\t"
+		"fmull %2\n\t"
+		"fldl %1\n\t"
+		"fsubp %%st,%%st(1)\n\t"
+		"fistpl %0\n\t"
+		"fwait\n\t"
+		"fninit"
+		: "=m" (*&i)
+		: "m" (*&x), "m" (*&y));
+	if (!i) {
+		printk("Ok, fpu using exception 16 error reporting.\n");
+		return;
+
+	}
+	printk("Ok, FDIV bug i%c86 system\n", '0'+x86);
+}
+
+static void check_hlt(void)
+{
+	printk("Checking 'hlt' instruction... ");
+	if (!hlt_works_ok) {
+		printk("disabled\n");
+		return;
+	}
+	__asm__ __volatile__("hlt ; hlt ; hlt ; hlt");
+	printk("Ok.\n");
+}
+
+static void check_bugs(void)
+{
+	check_fpu();
+	check_hlt();
+}
+
+asmlinkage void start_kernel(void)
+{
+/*
+ * Interrupts are still disabled. Do necessary setups, then
+ * enable them
+ */
+	set_call_gate(&default_ldt,lcall7);
+ 	ROOT_DEV = ORIG_ROOT_DEV;
+ 	drive_info = DRIVE_INFO;
+ 	screen_info = SCREEN_INFO;
+	aux_device_present = AUX_DEVICE_INFO;
+	memory_end = (1<<20) + (EXT_MEM_K<<10);
+	memory_end &= PAGE_MASK;
+	ramdisk_size = RAMDISK_SIZE;
+	copy_options(command_line,COMMAND_LINE);
+#ifdef CONFIG_MAX_16M
+	if (memory_end > 16*1024*1024)
+		memory_end = 16*1024*1024;
+#endif
+	if (MOUNT_ROOT_RDONLY)
+		root_mountflags |= MS_RDONLY;
+	if ((unsigned long)&end >= (1024*1024)) {
+		memory_start = (unsigned long) &end;
+		low_memory_start = PAGE_SIZE;
+	} else {
+		memory_start = 1024*1024;
+		low_memory_start = (unsigned long) &end;
+	}
+	low_memory_start = PAGE_ALIGN(low_memory_start);
+	memory_start = paging_init(memory_start,memory_end);
+	if (strncmp((char*)0x0FFFD9, "EISA", 4) == 0)
+		EISA_bus = 1;
+	trap_init();
+	init_IRQ();
+	sched_init();
+	parse_options(command_line);
+	init_modules();
+#ifdef CONFIG_PROFILE
+	prof_buffer = (unsigned long *) memory_start;
+	prof_len = (unsigned long) &end;
+	prof_len >>= 2;
+	memory_start += prof_len * sizeof(unsigned long);
+#endif
+	memory_start = console_init(memory_start,memory_end);
+	memory_start = bios32_init(memory_start,memory_end);
+	memory_start = kmalloc_init(memory_start,memory_end);
+	memory_start = chr_dev_init(memory_start,memory_end);
+	memory_start = blk_dev_init(memory_start,memory_end);
+	sti();
+	calibrate_delay();
+#ifdef CONFIG_SCSI
+	memory_start = scsi_dev_init(memory_start,memory_end);
+#endif
+#ifdef CONFIG_INET
+	memory_start = net_dev_init(memory_start,memory_end);
+#endif
+	memory_start = inode_init(memory_start,memory_end);
+	memory_start = file_table_init(memory_start,memory_end);
+	memory_start = name_cache_init(memory_start,memory_end);
+	mem_init(low_memory_start,memory_start,memory_end);
+	buffer_init();
+	time_init();
+	sock_init();
+#ifdef CONFIG_SYSVIPC
+	ipc_init();
+#endif
+	sti();
+	check_bugs();
+
+	system_utsname.machine[1] = '0' + x86;
+	printk(linux_banner);
+
+	move_to_user_mode();
+	if (!fork())		/* we count on this going ok */
+		init();
+/*
+ * task[0] is meant to be used as an "idle" task: it may not sleep, but
+ * it might do some general things like count free pages or it could be
+ * used to implement a reasonable LRU algorithm for the paging routines:
+ * anything that can be useful, but shouldn't take time from the real
+ * processes.
+ *
+ * Right now task[0] just does a infinite idle loop.
+ */
+	for(;;)
+		idle();
+}
+
+static int printf(const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	write(1,printbuf,i=vsprintf(printbuf, fmt, args));
+	va_end(args);
+	return i;
+}
+
+void init(void)
+{
+	int pid,i;
+
+	setup();
+	sprintf(term, "TERM=con%dx%d", ORIG_VIDEO_COLS, ORIG_VIDEO_LINES);
+
+	#ifdef CONFIG_UMSDOS_FS
+	{
+		/*
+			When mounting a umsdos fs as root, we detect
+			the pseudo_root (/linux) and initialise it here.
+			pseudo_root is defined in fs/umsdos/inode.c
+		*/
+		extern struct inode *pseudo_root;
+		if (pseudo_root != NULL){
+			current->fs->root = pseudo_root;
+			current->fs->pwd  = pseudo_root;
+		}
+	}
+	#endif
+
+	(void) open("/dev/tty1",O_RDWR,0);
+	(void) dup(0);
+	(void) dup(0);
+
+	execve("/etc/init",argv_init,envp_init);
+	execve("/bin/init",argv_init,envp_init);
+	execve("/sbin/init",argv_init,envp_init);
+	/* if this fails, fall through to original stuff */
+
+	if (!(pid=fork())) {
+		close(0);
+		if (open("/etc/rc",O_RDONLY,0))
+			_exit(1);
+		execve("/bin/sh",argv_rc,envp_rc);
+		_exit(2);
+	}
+	if (pid>0)
+		while (pid != wait(&i))
+			/* nothing */;
+	while (1) {
+		if ((pid = fork()) < 0) {
+			printf("Fork failed in init\n\r");
+			continue;
+		}
+		if (!pid) {
+			close(0);close(1);close(2);
+			setsid();
+			(void) open("/dev/tty1",O_RDWR,0);
+			(void) dup(0);
+			(void) dup(0);
+			_exit(execve("/bin/sh",argv,envp));
+		}
+		while (1)
+			if (pid == wait(&i))
+				break;
+		printf("\n\rchild %d died with code %04x\n\r",pid,i);
+		sync();
+	}
+	_exit(0);
+}