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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>
9: #include <fcntl.h>
1.1 root 10: #include <time.h>
11:
1.1.1.7 root 12: #include <sys/types.h>
13:
14: #include <asm/system.h>
15: #include <asm/io.h>
16:
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)
43: static inline _syscall1(int,close,int,fd)
44: static inline _syscall3(pid_t,waitpid,pid_t,pid,int *,wait_stat,int,options)
1.1 root 45:
1.1.1.7 root 46: static inline pid_t wait(int * wait_stat)
47: {
48: return waitpid(-1,wait_stat,0);
49: }
1.1.1.4 root 50:
1.1 root 51: static char printbuf[1024];
52:
53: extern int vsprintf();
54: extern void init(void);
1.1.1.2 root 55: extern void blk_dev_init(void);
1.1.1.8 ! root 56: extern long chr_dev_init(long);
1.1 root 57: extern void hd_init(void);
1.1.1.2 root 58: extern void floppy_init(void);
1.1.1.7 root 59: extern void sock_init(void);
1.1.1.2 root 60: extern void mem_init(long start, long end);
1.1.1.3 root 61: extern long rd_init(long mem_start, int length);
1.1 root 62: extern long kernel_mktime(struct tm * tm);
1.1.1.4 root 63:
1.1.1.7 root 64: #ifdef CONFIG_SCSI
65: extern void scsi_dev_init(void);
66: #endif
67:
1.1.1.4 root 68: static int sprintf(char * str, const char *fmt, ...)
69: {
70: va_list args;
71: int i;
72:
73: va_start(args, fmt);
74: i = vsprintf(str, fmt, args);
75: va_end(args);
76: return i;
77: }
1.1 root 78:
79: /*
1.1.1.2 root 80: * This is set up by the setup-routine at boot-time
81: */
82: #define EXT_MEM_K (*(unsigned short *)0x90002)
1.1.1.4 root 83: #define CON_ROWS ((*(unsigned short *)0x9000e) & 0xff)
84: #define CON_COLS (((*(unsigned short *)0x9000e) & 0xff00) >> 8)
1.1.1.2 root 85: #define DRIVE_INFO (*(struct drive_info *)0x90080)
86: #define ORIG_ROOT_DEV (*(unsigned short *)0x901FC)
87:
88: /*
1.1 root 89: * Yeah, yeah, it's ugly, but I cannot find how to do this correctly
90: * and this seems to work. I anybody has more info on the real-time
91: * clock I'd be interested. Most of this was trial and error, and some
92: * bios-listing reading. Urghh.
93: */
94:
95: #define CMOS_READ(addr) ({ \
96: outb_p(0x80|addr,0x70); \
97: inb_p(0x71); \
98: })
99:
100: #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
101:
102: static void time_init(void)
103: {
104: struct tm time;
105:
106: do {
107: time.tm_sec = CMOS_READ(0);
108: time.tm_min = CMOS_READ(2);
109: time.tm_hour = CMOS_READ(4);
110: time.tm_mday = CMOS_READ(7);
1.1.1.2 root 111: time.tm_mon = CMOS_READ(8);
1.1 root 112: time.tm_year = CMOS_READ(9);
113: } while (time.tm_sec != CMOS_READ(0));
114: BCD_TO_BIN(time.tm_sec);
115: BCD_TO_BIN(time.tm_min);
116: BCD_TO_BIN(time.tm_hour);
117: BCD_TO_BIN(time.tm_mday);
118: BCD_TO_BIN(time.tm_mon);
119: BCD_TO_BIN(time.tm_year);
1.1.1.2 root 120: time.tm_mon--;
1.1 root 121: startup_time = kernel_mktime(&time);
122: }
123:
1.1.1.2 root 124: static long memory_end = 0;
125: static long buffer_memory_end = 0;
1.1.1.3 root 126: static long main_memory_start = 0;
1.1.1.4 root 127: static char term[32];
128:
1.1.1.5 root 129: static char * argv_init[] = { "/bin/init", NULL };
130: static char * envp_init[] = { "HOME=/", NULL, NULL };
131:
1.1.1.4 root 132: static char * argv_rc[] = { "/bin/sh", NULL };
133: static char * envp_rc[] = { "HOME=/", NULL ,NULL };
134:
135: static char * argv[] = { "-/bin/sh",NULL };
136: static char * envp[] = { "HOME=/usr/root", NULL, NULL };
1.1.1.2 root 137:
138: struct drive_info { char dummy[32]; } drive_info;
139:
1.1.1.5 root 140: void start_kernel(void)
141: {
1.1 root 142: /*
143: * Interrupts are still disabled. Do necessary setups, then
144: * enable them
145: */
1.1.1.2 root 146: ROOT_DEV = ORIG_ROOT_DEV;
1.1.1.4 root 147: sprintf(term, "TERM=con%dx%d", CON_COLS, CON_ROWS);
148: envp[1] = term;
149: envp_rc[1] = term;
1.1.1.5 root 150: envp_init[1] = term;
1.1.1.2 root 151: drive_info = DRIVE_INFO;
152: memory_end = (1<<20) + (EXT_MEM_K<<10);
153: memory_end &= 0xfffff000;
154: if (memory_end > 16*1024*1024)
155: memory_end = 16*1024*1024;
1.1.1.5 root 156: if (memory_end >= 12*1024*1024)
1.1.1.3 root 157: buffer_memory_end = 4*1024*1024;
1.1.1.5 root 158: else if (memory_end >= 6*1024*1024)
1.1.1.2 root 159: buffer_memory_end = 2*1024*1024;
1.1.1.5 root 160: else if (memory_end >= 4*1024*1024)
161: buffer_memory_end = 3*512*1024;
1.1.1.2 root 162: else
163: buffer_memory_end = 1*1024*1024;
1.1.1.3 root 164: main_memory_start = buffer_memory_end;
165: #ifdef RAMDISK
166: main_memory_start += rd_init(main_memory_start, RAMDISK*1024);
167: #endif
1.1 root 168: trap_init();
1.1.1.7 root 169: sched_init();
1.1.1.8 ! root 170: main_memory_start = chr_dev_init(main_memory_start);
1.1.1.7 root 171: blk_dev_init();
1.1.1.8 ! root 172: mem_init(main_memory_start,memory_end);
1.1.1.2 root 173: time_init();
1.1.1.7 root 174: printk("Linux version " UTS_RELEASE " " __DATE__ " " __TIME__ "\n");
1.1.1.2 root 175: buffer_init(buffer_memory_end);
1.1 root 176: hd_init();
1.1.1.2 root 177: floppy_init();
1.1.1.7 root 178: sock_init();
1.1 root 179: sti();
1.1.1.7 root 180: #ifdef CONFIG_SCSI
181: scsi_dev_init();
182: #endif
1.1 root 183: move_to_user_mode();
184: if (!fork()) { /* we count on this going ok */
185: init();
186: }
187: /*
188: * NOTE!! For any other task 'pause()' would mean we have to get a
189: * signal to awaken, but task0 is the sole exception (see 'schedule()')
190: * as task 0 gets activated at every idle moment (when no other tasks
191: * can run). For task0 'pause()' just means we go check if some other
192: * task can run, and if not we return here.
193: */
1.1.1.4 root 194: for(;;)
195: __asm__("int $0x80"::"a" (__NR_pause):"ax");
1.1 root 196: }
197:
198: static int printf(const char *fmt, ...)
199: {
200: va_list args;
201: int i;
202:
203: va_start(args, fmt);
204: write(1,printbuf,i=vsprintf(printbuf, fmt, args));
205: va_end(args);
206: return i;
207: }
208:
209: void init(void)
210: {
1.1.1.3 root 211: int pid,i;
1.1 root 212:
1.1.1.2 root 213: setup((void *) &drive_info);
1.1.1.4 root 214: (void) open("/dev/tty1",O_RDWR,0);
1.1 root 215: (void) dup(0);
216: (void) dup(0);
217: printf("%d buffers = %d bytes buffer space\n\r",NR_BUFFERS,
218: NR_BUFFERS*BLOCK_SIZE);
1.1.1.3 root 219: printf("Free mem: %d bytes\n\r",memory_end-main_memory_start);
1.1.1.5 root 220:
1.1.1.6 root 221: execve("/etc/init",argv_init,envp_init);
1.1.1.5 root 222: execve("/bin/init",argv_init,envp_init);
223: /* if this fails, fall through to original stuff */
224:
1.1.1.3 root 225: if (!(pid=fork())) {
226: close(0);
227: if (open("/etc/rc",O_RDONLY,0))
228: _exit(1);
229: execve("/bin/sh",argv_rc,envp_rc);
230: _exit(2);
231: }
232: if (pid>0)
233: while (pid != wait(&i))
234: /* nothing */;
235: while (1) {
236: if ((pid=fork())<0) {
237: printf("Fork failed in init\r\n");
238: continue;
239: }
240: if (!pid) {
241: close(0);close(1);close(2);
242: setsid();
1.1.1.4 root 243: (void) open("/dev/tty1",O_RDWR,0);
1.1.1.3 root 244: (void) dup(0);
245: (void) dup(0);
246: _exit(execve("/bin/sh",argv,envp));
247: }
248: while (1)
249: if (pid == wait(&i))
250: break;
251: printf("\n\rchild %d died with code %04x\n\r",pid,i);
252: sync();
1.1 root 253: }
254: _exit(0); /* NOTE! _exit, not exit() */
255: }
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