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1.1.1.2 root 1: /*
2: * linux/init/main.c
3: *
4: * (C) 1991 Linus Torvalds
5: */
6:
1.1.1.7 root 7: #include <stddef.h>
8: #include <stdarg.h>
1.1 root 9: #include <time.h>
10:
1.1.1.7 root 11: #include <sys/types.h>
12:
13: #include <asm/system.h>
14: #include <asm/io.h>
15:
1.1.1.9 ! root 16: #include <linux/fcntl.h>
1.1.1.7 root 17: #include <linux/config.h>
18: #include <linux/sched.h>
19: #include <linux/tty.h>
20: #include <linux/head.h>
21: #include <linux/unistd.h>
22:
1.1 root 23: /*
24: * we need this inline - forking from kernel space will result
25: * in NO COPY ON WRITE (!!!), until an execve is executed. This
26: * is no problem, but for the stack. This is handled by not letting
27: * main() use the stack at all after fork(). Thus, no function
28: * calls - which means inline code for fork too, as otherwise we
29: * would use the stack upon exit from 'fork()'.
30: *
31: * Actually only pause and fork are needed inline, so that there
32: * won't be any messing with the stack from main(), but we define
33: * some others too.
34: */
35: static inline _syscall0(int,fork)
36: static inline _syscall0(int,pause)
1.1.1.2 root 37: static inline _syscall1(int,setup,void *,BIOS)
1.1 root 38: static inline _syscall0(int,sync)
1.1.1.7 root 39: static inline _syscall0(pid_t,setsid)
40: static inline _syscall3(int,write,int,fd,const char *,buf,off_t,count)
41: static inline _syscall1(int,dup,int,fd)
42: static inline _syscall3(int,execve,const char *,file,char **,argv,char **,envp)
1.1.1.9 ! root 43: static inline _syscall3(int,open,const char *,file,int,flag,int,mode)
1.1.1.7 root 44: static inline _syscall1(int,close,int,fd)
45: static inline _syscall3(pid_t,waitpid,pid_t,pid,int *,wait_stat,int,options)
1.1 root 46:
1.1.1.7 root 47: static inline pid_t wait(int * wait_stat)
48: {
49: return waitpid(-1,wait_stat,0);
50: }
1.1.1.4 root 51:
1.1 root 52: static char printbuf[1024];
53:
54: extern int vsprintf();
55: extern void init(void);
1.1.1.9 ! root 56: extern long blk_dev_init(long,long);
! 57: extern long chr_dev_init(long,long);
1.1 root 58: extern void hd_init(void);
1.1.1.2 root 59: extern void floppy_init(void);
1.1.1.7 root 60: extern void sock_init(void);
1.1.1.2 root 61: extern void mem_init(long start, long end);
1.1.1.3 root 62: extern long rd_init(long mem_start, int length);
1.1 root 63: extern long kernel_mktime(struct tm * tm);
1.1.1.4 root 64:
1.1.1.7 root 65: #ifdef CONFIG_SCSI
66: extern void scsi_dev_init(void);
67: #endif
68:
1.1.1.4 root 69: static int sprintf(char * str, const char *fmt, ...)
70: {
71: va_list args;
72: int i;
73:
74: va_start(args, fmt);
75: i = vsprintf(str, fmt, args);
76: va_end(args);
77: return i;
78: }
1.1 root 79:
80: /*
1.1.1.2 root 81: * This is set up by the setup-routine at boot-time
82: */
83: #define EXT_MEM_K (*(unsigned short *)0x90002)
1.1.1.4 root 84: #define CON_ROWS ((*(unsigned short *)0x9000e) & 0xff)
85: #define CON_COLS (((*(unsigned short *)0x9000e) & 0xff00) >> 8)
1.1.1.2 root 86: #define DRIVE_INFO (*(struct drive_info *)0x90080)
87: #define ORIG_ROOT_DEV (*(unsigned short *)0x901FC)
88:
89: /*
1.1 root 90: * Yeah, yeah, it's ugly, but I cannot find how to do this correctly
91: * and this seems to work. I anybody has more info on the real-time
92: * clock I'd be interested. Most of this was trial and error, and some
93: * bios-listing reading. Urghh.
94: */
95:
96: #define CMOS_READ(addr) ({ \
97: outb_p(0x80|addr,0x70); \
98: inb_p(0x71); \
99: })
100:
101: #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
102:
103: static void time_init(void)
104: {
105: struct tm time;
106:
107: do {
108: time.tm_sec = CMOS_READ(0);
109: time.tm_min = CMOS_READ(2);
110: time.tm_hour = CMOS_READ(4);
111: time.tm_mday = CMOS_READ(7);
1.1.1.2 root 112: time.tm_mon = CMOS_READ(8);
1.1 root 113: time.tm_year = CMOS_READ(9);
114: } while (time.tm_sec != CMOS_READ(0));
115: BCD_TO_BIN(time.tm_sec);
116: BCD_TO_BIN(time.tm_min);
117: BCD_TO_BIN(time.tm_hour);
118: BCD_TO_BIN(time.tm_mday);
119: BCD_TO_BIN(time.tm_mon);
120: BCD_TO_BIN(time.tm_year);
1.1.1.2 root 121: time.tm_mon--;
1.1 root 122: startup_time = kernel_mktime(&time);
123: }
124:
1.1.1.2 root 125: static long memory_end = 0;
126: static long buffer_memory_end = 0;
1.1.1.3 root 127: static long main_memory_start = 0;
1.1.1.4 root 128: static char term[32];
129:
1.1.1.5 root 130: static char * argv_init[] = { "/bin/init", NULL };
131: static char * envp_init[] = { "HOME=/", NULL, NULL };
132:
1.1.1.4 root 133: static char * argv_rc[] = { "/bin/sh", NULL };
134: static char * envp_rc[] = { "HOME=/", NULL ,NULL };
135:
136: static char * argv[] = { "-/bin/sh",NULL };
137: static char * envp[] = { "HOME=/usr/root", NULL, NULL };
1.1.1.2 root 138:
139: struct drive_info { char dummy[32]; } drive_info;
140:
1.1.1.5 root 141: void start_kernel(void)
142: {
1.1 root 143: /*
144: * Interrupts are still disabled. Do necessary setups, then
145: * enable them
146: */
1.1.1.2 root 147: ROOT_DEV = ORIG_ROOT_DEV;
1.1.1.4 root 148: sprintf(term, "TERM=con%dx%d", CON_COLS, CON_ROWS);
149: envp[1] = term;
150: envp_rc[1] = term;
1.1.1.5 root 151: envp_init[1] = term;
1.1.1.2 root 152: drive_info = DRIVE_INFO;
153: memory_end = (1<<20) + (EXT_MEM_K<<10);
154: memory_end &= 0xfffff000;
155: if (memory_end > 16*1024*1024)
156: memory_end = 16*1024*1024;
1.1.1.5 root 157: if (memory_end >= 12*1024*1024)
1.1.1.3 root 158: buffer_memory_end = 4*1024*1024;
1.1.1.5 root 159: else if (memory_end >= 6*1024*1024)
1.1.1.2 root 160: buffer_memory_end = 2*1024*1024;
1.1.1.5 root 161: else if (memory_end >= 4*1024*1024)
162: buffer_memory_end = 3*512*1024;
1.1.1.2 root 163: else
164: buffer_memory_end = 1*1024*1024;
1.1.1.3 root 165: main_memory_start = buffer_memory_end;
1.1 root 166: trap_init();
1.1.1.7 root 167: sched_init();
1.1.1.9 ! root 168: main_memory_start = chr_dev_init(main_memory_start,memory_end);
! 169: main_memory_start = blk_dev_init(main_memory_start,memory_end);
1.1.1.8 root 170: mem_init(main_memory_start,memory_end);
1.1.1.2 root 171: time_init();
1.1.1.7 root 172: printk("Linux version " UTS_RELEASE " " __DATE__ " " __TIME__ "\n");
1.1.1.2 root 173: buffer_init(buffer_memory_end);
1.1 root 174: hd_init();
1.1.1.2 root 175: floppy_init();
1.1.1.7 root 176: sock_init();
1.1 root 177: sti();
1.1.1.7 root 178: #ifdef CONFIG_SCSI
179: scsi_dev_init();
180: #endif
1.1 root 181: move_to_user_mode();
182: if (!fork()) { /* we count on this going ok */
183: init();
184: }
185: /*
186: * NOTE!! For any other task 'pause()' would mean we have to get a
187: * signal to awaken, but task0 is the sole exception (see 'schedule()')
188: * as task 0 gets activated at every idle moment (when no other tasks
189: * can run). For task0 'pause()' just means we go check if some other
190: * task can run, and if not we return here.
191: */
1.1.1.4 root 192: for(;;)
193: __asm__("int $0x80"::"a" (__NR_pause):"ax");
1.1 root 194: }
195:
196: static int printf(const char *fmt, ...)
197: {
198: va_list args;
199: int i;
200:
201: va_start(args, fmt);
202: write(1,printbuf,i=vsprintf(printbuf, fmt, args));
203: va_end(args);
204: return i;
205: }
206:
207: void init(void)
208: {
1.1.1.3 root 209: int pid,i;
1.1 root 210:
1.1.1.2 root 211: setup((void *) &drive_info);
1.1.1.4 root 212: (void) open("/dev/tty1",O_RDWR,0);
1.1 root 213: (void) dup(0);
214: (void) dup(0);
215: printf("%d buffers = %d bytes buffer space\n\r",NR_BUFFERS,
216: NR_BUFFERS*BLOCK_SIZE);
1.1.1.3 root 217: printf("Free mem: %d bytes\n\r",memory_end-main_memory_start);
1.1.1.5 root 218:
1.1.1.6 root 219: execve("/etc/init",argv_init,envp_init);
1.1.1.5 root 220: execve("/bin/init",argv_init,envp_init);
221: /* if this fails, fall through to original stuff */
222:
1.1.1.3 root 223: if (!(pid=fork())) {
224: close(0);
225: if (open("/etc/rc",O_RDONLY,0))
226: _exit(1);
227: execve("/bin/sh",argv_rc,envp_rc);
228: _exit(2);
229: }
230: if (pid>0)
231: while (pid != wait(&i))
232: /* nothing */;
233: while (1) {
234: if ((pid=fork())<0) {
235: printf("Fork failed in init\r\n");
236: continue;
237: }
238: if (!pid) {
239: close(0);close(1);close(2);
240: setsid();
1.1.1.4 root 241: (void) open("/dev/tty1",O_RDWR,0);
1.1.1.3 root 242: (void) dup(0);
243: (void) dup(0);
244: _exit(execve("/bin/sh",argv,envp));
245: }
246: while (1)
247: if (pid == wait(&i))
248: break;
249: printf("\n\rchild %d died with code %04x\n\r",pid,i);
250: sync();
1.1 root 251: }
252: _exit(0); /* NOTE! _exit, not exit() */
253: }
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