| /* |
| * linux/init/main.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #include <stdarg.h> |
| |
| #include <asm/system.h> |
| #include <asm/io.h> |
| |
| #include <linux/mktime.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> |
| |
| extern unsigned long * prof_buffer; |
| extern unsigned long prof_len; |
| extern char edata, end; |
| extern char *linux_banner; |
| |
| /* |
| * 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. |
| */ |
| static inline _syscall0(int,idle) |
| static inline _syscall0(int,fork) |
| static inline _syscall0(int,pause) |
| static inline _syscall1(int,setup,void *,BIOS) |
| 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 char empty_zero_page[4096]; |
| extern int vsprintf(char *,const char *,va_list); |
| extern void init(void); |
| extern void init_IRQ(void); |
| extern long blk_dev_init(long,long); |
| extern long chr_dev_init(long,long); |
| extern void floppy_init(void); |
| extern void sock_init(void); |
| extern long rd_init(long mem_start, int length); |
| extern long kernel_mktime(struct mktime * time); |
| extern unsigned long simple_strtoul(const char *,char **,unsigned int); |
| |
| extern void hd_setup(char *str, int *ints); |
| extern void bmouse_setup(char *str, int *ints); |
| extern void eth_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)) |
| |
| /* |
| * Yeah, yeah, it's ugly, but I cannot find how to do this correctly |
| * and this seems to work. I anybody has more info on the real-time |
| * clock I'd be interested. Most of this was trial and error, and some |
| * bios-listing reading. Urghh. |
| */ |
| |
| #define CMOS_READ(addr) ({ \ |
| outb_p(addr,0x70); \ |
| inb_p(0x71); \ |
| }) |
| |
| #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10) |
| |
| static void time_init(void) |
| { |
| struct mktime time; |
| int i; |
| |
| for (i = 0 ; i < 1000000 ; i++) |
| if (!(CMOS_READ(10) & 0x80)) |
| break; |
| do { |
| time.sec = CMOS_READ(0); |
| time.min = CMOS_READ(2); |
| time.hour = CMOS_READ(4); |
| time.day = CMOS_READ(7); |
| time.mon = CMOS_READ(8); |
| time.year = CMOS_READ(9); |
| } while (time.sec != CMOS_READ(0)); |
| BCD_TO_BIN(time.sec); |
| BCD_TO_BIN(time.min); |
| BCD_TO_BIN(time.hour); |
| BCD_TO_BIN(time.day); |
| BCD_TO_BIN(time.mon); |
| BCD_TO_BIN(time.year); |
| time.mon--; |
| startup_time = kernel_mktime(&time); |
| } |
| |
| 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 * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; |
| static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=console", NULL, }; |
| |
| static char * argv_rc[] = { "/bin/sh", NULL }; |
| static char * envp_rc[] = { "HOME=/", "TERM=console", NULL }; |
| |
| static char * argv[] = { "-/bin/sh",NULL }; |
| static char * envp[] = { "HOME=/usr/root", "TERM=console", 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[80] = { 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[] = { |
| #ifdef CONFIG_INET |
| { "ether=", eth_setup }, |
| #endif |
| #ifdef CONFIG_BLK_DEV_HD |
| { "hd=", hd_setup }, |
| #endif |
| #ifdef CONFIG_BUSMOUSE |
| { "bmouse=", bmouse_setup }, |
| #endif |
| { 0, 0 } |
| }; |
| |
| 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(0); |
| } |
| i++; |
| } |
| return(1); |
| } |
| |
| unsigned long loops_per_sec = 1; |
| |
| static void calibrate_delay(void) |
| { |
| int ticks; |
| |
| printk("Calibrating delay loop.. "); |
| while (loops_per_sec <<= 1) { |
| 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 - %d.%02d BogoMips (tm)\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", NULL }; |
| int devnums[] = { 0x300, 0x340, 0x800, 0x810, 0x820, 0x830, 0x840, 0x200, 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,16); |
| break; |
| } |
| } |
| } else if (!strcmp(line,"ro")) |
| root_mountflags |= MS_RDONLY; |
| else if (!strcmp(line,"rw")) |
| root_mountflags &= ~MS_RDONLY; |
| else if (!strcmp(line,"no387")) { |
| hard_math = 0; |
| __asm__("movl %%cr0,%%eax\n\t" |
| "orl $0xE,%%eax\n\t" |
| "movl %%eax,%%cr0\n\t" : : : "ax"); |
| } else |
| checksetup(line); |
| /* |
| * 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 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); |
| } |
| |
| extern "C" void start_kernel(void) |
| { |
| /* |
| * Interrupts are still disabled. Do necessary setups, then |
| * enable them |
| */ |
| 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 &= 0xfffff000; |
| ramdisk_size = RAMDISK_SIZE; |
| strcpy(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 = 4096; |
| } else { |
| memory_start = 1024*1024; |
| low_memory_start = (unsigned long) &end; |
| } |
| low_memory_start += 0xfff; |
| low_memory_start &= 0xfffff000; |
| memory_start = paging_init(memory_start,memory_end); |
| trap_init(); |
| init_IRQ(); |
| sched_init(); |
| parse_options(command_line); |
| #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 = chr_dev_init(memory_start,memory_end); |
| memory_start = blk_dev_init(memory_start,memory_end); |
| #ifdef CONFIG_SCSI |
| memory_start = scsi_dev_init(memory_start,memory_end); |
| #endif |
| memory_start = inode_init(memory_start,memory_end); |
| memory_start = file_table_init(memory_start,memory_end); |
| mem_init(low_memory_start,memory_start,memory_end); |
| buffer_init(); |
| time_init(); |
| floppy_init(); |
| sock_init(); |
| #ifdef CONFIG_SYSVIPC |
| ipc_init(); |
| #endif |
| sti(); |
| calibrate_delay(); |
| /* |
| * 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.. |
| */ |
| if (hard_math) { |
| unsigned short control_word; |
| |
| 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) |
| printk("Ok, fpu using %s error reporting.\n", |
| ignore_irq13?"exception 16":"irq13"); |
| } |
| 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((void *) &drive_info); |
| (void) open("/dev/tty1",O_RDWR,0); |
| (void) dup(0); |
| (void) dup(0); |
| |
| printf(linux_banner); |
| 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); |
| } |