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