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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)
1.1.1.4 ! root 76: #define ORIG_SWAP_DEV (*(unsigned short *)0x901FA)
1.1.1.2 root 77:
78: /*
1.1 root 79: * Yeah, yeah, it's ugly, but I cannot find how to do this correctly
80: * and this seems to work. I anybody has more info on the real-time
81: * clock I'd be interested. Most of this was trial and error, and some
82: * bios-listing reading. Urghh.
83: */
84:
85: #define CMOS_READ(addr) ({ \
86: outb_p(0x80|addr,0x70); \
87: inb_p(0x71); \
88: })
89:
90: #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
91:
92: static void time_init(void)
93: {
94: struct tm time;
95:
96: do {
97: time.tm_sec = CMOS_READ(0);
98: time.tm_min = CMOS_READ(2);
99: time.tm_hour = CMOS_READ(4);
100: time.tm_mday = CMOS_READ(7);
1.1.1.2 root 101: time.tm_mon = CMOS_READ(8);
1.1 root 102: time.tm_year = CMOS_READ(9);
103: } while (time.tm_sec != CMOS_READ(0));
104: BCD_TO_BIN(time.tm_sec);
105: BCD_TO_BIN(time.tm_min);
106: BCD_TO_BIN(time.tm_hour);
107: BCD_TO_BIN(time.tm_mday);
108: BCD_TO_BIN(time.tm_mon);
109: BCD_TO_BIN(time.tm_year);
1.1.1.2 root 110: time.tm_mon--;
1.1 root 111: startup_time = kernel_mktime(&time);
112: }
113:
1.1.1.2 root 114: static long memory_end = 0;
115: static long buffer_memory_end = 0;
1.1.1.3 root 116: static long main_memory_start = 0;
1.1.1.4 ! root 117: static char term[32];
! 118:
! 119: static char * argv_rc[] = { "/bin/sh", NULL };
! 120: static char * envp_rc[] = { "HOME=/", NULL ,NULL };
! 121:
! 122: static char * argv[] = { "-/bin/sh",NULL };
! 123: static char * envp[] = { "HOME=/usr/root", NULL, NULL };
1.1.1.2 root 124:
125: struct drive_info { char dummy[32]; } drive_info;
126:
1.1 root 127: void main(void) /* This really IS void, no error here. */
128: { /* The startup routine assumes (well, ...) this */
129: /*
130: * Interrupts are still disabled. Do necessary setups, then
131: * enable them
132: */
1.1.1.2 root 133: ROOT_DEV = ORIG_ROOT_DEV;
1.1.1.4 ! root 134: SWAP_DEV = ORIG_SWAP_DEV;
! 135: sprintf(term, "TERM=con%dx%d", CON_COLS, CON_ROWS);
! 136: envp[1] = term;
! 137: envp_rc[1] = term;
1.1.1.2 root 138: drive_info = DRIVE_INFO;
139: memory_end = (1<<20) + (EXT_MEM_K<<10);
140: memory_end &= 0xfffff000;
141: if (memory_end > 16*1024*1024)
142: memory_end = 16*1024*1024;
1.1.1.3 root 143: if (memory_end > 12*1024*1024)
144: buffer_memory_end = 4*1024*1024;
145: else if (memory_end > 6*1024*1024)
1.1.1.2 root 146: buffer_memory_end = 2*1024*1024;
147: else
148: buffer_memory_end = 1*1024*1024;
1.1.1.3 root 149: main_memory_start = buffer_memory_end;
150: #ifdef RAMDISK
151: main_memory_start += rd_init(main_memory_start, RAMDISK*1024);
152: #endif
153: mem_init(main_memory_start,memory_end);
1.1 root 154: trap_init();
1.1.1.2 root 155: blk_dev_init();
156: chr_dev_init();
157: tty_init();
158: time_init();
1.1 root 159: sched_init();
1.1.1.2 root 160: buffer_init(buffer_memory_end);
1.1 root 161: hd_init();
1.1.1.2 root 162: floppy_init();
1.1 root 163: sti();
164: move_to_user_mode();
165: if (!fork()) { /* we count on this going ok */
166: init();
167: }
168: /*
169: * NOTE!! For any other task 'pause()' would mean we have to get a
170: * signal to awaken, but task0 is the sole exception (see 'schedule()')
171: * as task 0 gets activated at every idle moment (when no other tasks
172: * can run). For task0 'pause()' just means we go check if some other
173: * task can run, and if not we return here.
174: */
1.1.1.4 ! root 175: for(;;)
! 176: __asm__("int $0x80"::"a" (__NR_pause):"ax");
1.1 root 177: }
178:
179: static int printf(const char *fmt, ...)
180: {
181: va_list args;
182: int i;
183:
184: va_start(args, fmt);
185: write(1,printbuf,i=vsprintf(printbuf, fmt, args));
186: va_end(args);
187: return i;
188: }
189:
190: void init(void)
191: {
1.1.1.3 root 192: int pid,i;
1.1 root 193:
1.1.1.2 root 194: setup((void *) &drive_info);
1.1.1.4 ! root 195: (void) open("/dev/tty1",O_RDWR,0);
1.1 root 196: (void) dup(0);
197: (void) dup(0);
198: printf("%d buffers = %d bytes buffer space\n\r",NR_BUFFERS,
199: NR_BUFFERS*BLOCK_SIZE);
1.1.1.3 root 200: printf("Free mem: %d bytes\n\r",memory_end-main_memory_start);
201: if (!(pid=fork())) {
202: close(0);
203: if (open("/etc/rc",O_RDONLY,0))
204: _exit(1);
205: execve("/bin/sh",argv_rc,envp_rc);
206: _exit(2);
207: }
208: if (pid>0)
209: while (pid != wait(&i))
210: /* nothing */;
211: while (1) {
212: if ((pid=fork())<0) {
213: printf("Fork failed in init\r\n");
214: continue;
215: }
216: if (!pid) {
217: close(0);close(1);close(2);
218: setsid();
1.1.1.4 ! root 219: (void) open("/dev/tty1",O_RDWR,0);
1.1.1.3 root 220: (void) dup(0);
221: (void) dup(0);
222: _exit(execve("/bin/sh",argv,envp));
223: }
224: while (1)
225: if (pid == wait(&i))
226: break;
227: printf("\n\rchild %d died with code %04x\n\r",pid,i);
228: sync();
1.1 root 229: }
230: _exit(0); /* NOTE! _exit, not exit() */
231: }
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