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Mercurial > hg > plan9front / sys/src/9/bcm/main.c

changeset 3216: 4b8b4a29def2
parent: e48d4208f76f
child: 69064e032a3e
author: Matthew Veety <mveety@gmail.com>
date: Sun, 12 Jan 2014 11:00:38 -0500
permissions: -rw-r--r--
description: added a segment for segattach(2) that gives access to the raspberry pi's gpio header.
1 #include "u.h"
2 #include "tos.h"
3 #include "../port/lib.h"
4 #include "mem.h"
5 #include "dat.h"
6 #include "fns.h"
7 
8 #include "init.h"
9 #include <pool.h>
10 
11 #include "reboot.h"
12 
13 /* Firmware compatibility */
14 #define Minfirmrev 326770
15 #define Minfirmdate "22 Jul 2012"
16 
17 /*
18  * Where configuration info is left for the loaded programme.
19  */
20 #define BOOTARGS ((char*)CONFADDR)
21 #define BOOTARGSLEN (MACHADDR-CONFADDR)
22 #define MAXCONF 64
23 #define MAXCONFLINE 160
24 
25 uintptr kseg0 = KZERO;
26 Mach* machaddr[MAXMACH];
27 Conf conf;
28 ulong memsize = 128*1024*1024;
29 
30 /*
31  * Option arguments from the command line.
32  * oargv[0] is the boot file.
33  */
34 static int oargc;
35 static char* oargv[20];
36 static char oargb[128];
37 static int oargblen;
38 
39 static uintptr sp; /* XXX - must go - user stack of init proc */
40 
41 /* store plan9.ini contents here at least until we stash them in #ec */
42 static char confname[MAXCONF][KNAMELEN];
43 static char confval[MAXCONF][MAXCONFLINE];
44 static int nconf;
45 
46 typedef struct Atag Atag;
47 struct Atag {
48  u32int size; /* size of atag in words, including this header */
49  u32int tag; /* atag type */
50  union {
51  u32int data[1]; /* actually [size-2] */
52  /* AtagMem */
53  struct {
54  u32int size;
55  u32int base;
56  } mem;
57  /* AtagCmdLine */
58  char cmdline[1]; /* actually [4*(size-2)] */
59  };
60 };
61 
62 enum {
63  AtagNone = 0x00000000,
64  AtagCore = 0x54410001,
65  AtagMem = 0x54410002,
66  AtagCmdline = 0x54410009,
67 };
68 
69 static int
70 findconf(char *name)
71 {
72  int i;
73 
74  for(i = 0; i < nconf; i++)
75  if(cistrcmp(confname[i], name) == 0)
76  return i;
77  return -1;
78 }
79 
80 char*
81 getconf(char *name)
82 {
83  int i;
84 
85  i = findconf(name);
86  if(i >= 0)
87  return confval[i];
88  return nil;
89 }
90 
91 void
92 addconf(char *name, char *val)
93 {
94  int i;
95 
96  i = findconf(name);
97  if(i < 0){
98  if(val == nil || nconf >= MAXCONF)
99  return;
100  i = nconf++;
101  strecpy(confname[i], confname[i]+sizeof(confname[i]), name);
102  }
103  strecpy(confval[i], confval[i]+sizeof(confval[i]), val);
104 }
105 
106 static void
107 writeconf(void)
108 {
109  char *p, *q;
110  int n;
111 
112  p = getconfenv();
113 
114  if(waserror()) {
115  free(p);
116  nexterror();
117  }
118 
119  /* convert to name=value\n format */
120  for(q=p; *q; q++) {
121  q += strlen(q);
122  *q = '=';
123  q += strlen(q);
124  *q = '\n';
125  }
126  n = q - p + 1;
127  if(n >= BOOTARGSLEN)
128  error("kernel configuration too large");
129  memmove(BOOTARGS, p, n);
130  memset(BOOTARGS + n, '\n', BOOTARGSLEN - n);
131  poperror();
132  free(p);
133 }
134 
135 static void
136 plan9iniinit(char *s, int cmdline)
137 {
138  char *toks[MAXCONF];
139  int i, c, n;
140  char *v;
141 
142  if((c = *s) < ' ' || c >= 0x80)
143  return;
144  if(cmdline)
145  n = tokenize(s, toks, MAXCONF);
146  else
147  n = getfields(s, toks, MAXCONF, 1, "\n");
148  for(i = 0; i < n; i++){
149  if(toks[i][0] == '#')
150  continue;
151  v = strchr(toks[i], '=');
152  if(v == nil)
153  continue;
154  *v++ = '\0';
155  addconf(toks[i], v);
156  }
157 }
158 
159 static void
160 ataginit(Atag *a)
161 {
162  int n;
163 
164  if(a->tag != AtagCore){
165  plan9iniinit((char*)a, 0);
166  return;
167  }
168  while(a->tag != AtagNone){
169  switch(a->tag){
170  case AtagMem:
171  /* use only first bank */
172  if(conf.mem[0].limit == 0 && a->mem.size != 0){
173  memsize = a->mem.size;
174  conf.mem[0].base = a->mem.base;
175  conf.mem[0].limit = a->mem.base + memsize;
176  }
177  break;
178  case AtagCmdline:
179  n = (a->size * sizeof(u32int)) - offsetof(Atag, cmdline[0]);
180  if(a->cmdline + n < BOOTARGS + BOOTARGSLEN)
181  a->cmdline[n] = 0;
182  else
183  BOOTARGS[BOOTARGSLEN-1] = 0;
184  plan9iniinit(a->cmdline, 1);
185  break;
186  }
187  a = (Atag*)((u32int*)a + a->size);
188  }
189 }
190 
191 void
192 machinit(void)
193 {
194  m->machno = 0;
195  machaddr[m->machno] = m;
196 
197  m->ticks = 1;
198  m->perf.period = 1;
199 
200  conf.nmach = 1;
201 
202  active.machs = 1;
203  active.exiting = 0;
204 
205  up = nil;
206 }
207 
208 static void
209 optionsinit(char* s)
210 {
211  strecpy(oargb, oargb+sizeof(oargb), s);
212 
213  oargblen = strlen(oargb);
214  oargc = tokenize(oargb, oargv, nelem(oargv)-1);
215  oargv[oargc] = nil;
216 }
217 
218 void
219 gpiomeminit(void)
220 {
221  Physseg seg;
222  memset(&seg, 0, sizeof seg);
223  seg.attr = SG_PHYSICAL;
224  seg.name = "gpio";
225  seg.pa = (VIRTIO+0x200000);
226  seg.size = 1;
227  addphysseg(&seg);
228 }
229 
230 
231 void
232 main(void)
233 {
234  extern char edata[], end[];
235  uint rev;
236 
237  okay(1);
238  m = (Mach*)MACHADDR;
239  memset(edata, 0, end - edata); /* clear bss */
240  machinit();
241  mmuinit1();
242 
243  optionsinit("/boot/boot boot");
244  quotefmtinstall();
245 
246  ataginit((Atag*)BOOTARGS);
247  confinit(); /* figures out amount of memory */
248  xinit();
249  uartconsinit();
250  screeninit();
251 
252  print("\nPlan 9 from Bell Labs\n");
253  rev = getfirmware();
254  print("firmware: rev %d\n", rev);
255  if(rev < Minfirmrev){
256  print("Sorry, firmware (start.elf) must be at least rev %d (%s)\n",
257  Minfirmrev, Minfirmdate);
258  for(;;)
259  ;
260  }
261  trapinit();
262  clockinit();
263  printinit();
264  timersinit();
265  cpuidprint();
266  archreset();
267 
268  procinit0();
269  initseg();
270  links();
271  chandevreset(); /* most devices are discovered here */
272  pageinit();
273  swapinit();
274  userinit();
275  gpiomeminit();
276  schedinit();
277  assert(0); /* shouldn't have returned */
278 }
279 
280 /*
281  * starting place for first process
282  */
283 void
284 init0(void)
285 {
286  int i;
287  char buf[2*KNAMELEN];
288 
289  up->nerrlab = 0;
290  coherence();
291  spllo();
292 
293  /*
294  * These are o.k. because rootinit is null.
295  * Then early kproc's will have a root and dot.
296  */
297  up->slash = namec("#/", Atodir, 0, 0);
298  pathclose(up->slash->path);
299  up->slash->path = newpath("/");
300  up->dot = cclone(up->slash);
301 
302  chandevinit();
303 
304  if(!waserror()){
305  snprint(buf, sizeof(buf), "%s %s", "ARM", conffile);
306  ksetenv("terminal", buf, 0);
307  ksetenv("cputype", "arm", 0);
308  if(cpuserver)
309  ksetenv("service", "cpu", 0);
310  else
311  ksetenv("service", "terminal", 0);
312  snprint(buf, sizeof(buf), "-a %s", getethermac());
313  ksetenv("etherargs", buf, 0);
314 
315  /* convert plan9.ini variables to #e and #ec */
316  for(i = 0; i < nconf; i++) {
317  ksetenv(confname[i], confval[i], 0);
318  ksetenv(confname[i], confval[i], 1);
319  }
320  poperror();
321  }
322  kproc("alarm", alarmkproc, 0);
323  touser(sp);
324  assert(0); /* shouldn't have returned */
325 }
326 
327 static void
328 bootargs(uintptr base)
329 {
330  int i;
331  ulong ssize;
332  char **av, *p;
333 
334  /*
335  * Push the boot args onto the stack.
336  * The initial value of the user stack must be such
337  * that the total used is larger than the maximum size
338  * of the argument list checked in syscall.
339  */
340  i = oargblen+1;
341  p = UINT2PTR(STACKALIGN(base + BY2PG - sizeof(Tos) - i));
342  memmove(p, oargb, i);
343 
344  /*
345  * Now push the argv pointers.
346  * The code jumped to by touser in lproc.s expects arguments
347  * main(char* argv0, ...)
348  * and calls
349  * startboot("/boot/boot", &argv0)
350  * not the usual (int argc, char* argv[])
351  */
352  av = (char**)(p - (oargc+1)*sizeof(char*));
353  ssize = base + BY2PG - PTR2UINT(av);
354  for(i = 0; i < oargc; i++)
355  *av++ = (oargv[i] - oargb) + (p - base) + (USTKTOP - BY2PG);
356  *av = nil;
357  sp = USTKTOP - ssize;
358 }
359 
360 /*
361  * create the first process
362  */
363 void
364 userinit(void)
365 {
366  Proc *p;
367  Segment *s;
368  KMap *k;
369  Page *pg;
370 
371  /* no processes yet */
372  up = nil;
373 
374  p = newproc();
375  p->pgrp = newpgrp();
376  p->egrp = smalloc(sizeof(Egrp));
377  p->egrp->ref = 1;
378  p->fgrp = dupfgrp(nil);
379  p->rgrp = newrgrp();
380  p->procmode = 0640;
381 
382  kstrdup(&eve, "");
383  kstrdup(&p->text, "*init*");
384  kstrdup(&p->user, eve);
385 
386  /*
387  * Kernel Stack
388  */
389  p->sched.pc = PTR2UINT(init0);
390  p->sched.sp = PTR2UINT(p->kstack+KSTACK-sizeof(up->s.args)-sizeof(uintptr));
391  p->sched.sp = STACKALIGN(p->sched.sp);
392 
393  /*
394  * User Stack
395  *
396  * Technically, newpage can't be called here because it
397  * should only be called when in a user context as it may
398  * try to sleep if there are no pages available, but that
399  * shouldn't be the case here.
400  */
401  s = newseg(SG_STACK, USTKTOP-USTKSIZE, USTKSIZE/BY2PG);
402  s->flushme++;
403  p->seg[SSEG] = s;
404  pg = newpage(1, 0, USTKTOP-BY2PG);
405  segpage(s, pg);
406  k = kmap(pg);
407  bootargs(VA(k));
408  kunmap(k);
409 
410  /*
411  * Text
412  */
413  s = newseg(SG_TEXT, UTZERO, 1);
414  p->seg[TSEG] = s;
415  pg = newpage(1, 0, UTZERO);
416  memset(pg->cachectl, PG_TXTFLUSH, sizeof(pg->cachectl));
417  segpage(s, pg);
418  k = kmap(s->map[0]->pages[0]);
419  memmove(UINT2PTR(VA(k)), initcode, sizeof initcode);
420  kunmap(k);
421 
422  ready(p);
423 }
424 
425 void
426 confinit(void)
427 {
428  int i;
429  ulong kpages;
430  uintptr pa;
431  char *p;
432 
433  if(0 && (p = getconf("service")) != nil){
434  if(strcmp(p, "cpu") == 0)
435  cpuserver = 1;
436  else if(strcmp(p,"terminal") == 0)
437  cpuserver = 0;
438  }
439  if((p = getconf("*maxmem")) != nil){
440  memsize = strtoul(p, 0, 0) - PHYSDRAM;
441  if (memsize < 16*MB) /* sanity */
442  memsize = 16*MB;
443  }
444 
445  getramsize(&conf.mem[0]);
446  if(conf.mem[0].limit == 0){
447  conf.mem[0].base = PHYSDRAM;
448  conf.mem[0].limit = PHYSDRAM + memsize;
449  }else if(p != nil)
450  conf.mem[0].limit = conf.mem[0].base + memsize;
451 
452  conf.npage = 0;
453  pa = PADDR(PGROUND(PTR2UINT(end)));
454 
455  /*
456  * we assume that the kernel is at the beginning of one of the
457  * contiguous chunks of memory and fits therein.
458  */
459  for(i=0; i<nelem(conf.mem); i++){
460  /* take kernel out of allocatable space */
461  if(pa > conf.mem[i].base && pa < conf.mem[i].limit)
462  conf.mem[i].base = pa;
463 
464  conf.mem[i].npage = (conf.mem[i].limit - conf.mem[i].base)/BY2PG;
465  conf.npage += conf.mem[i].npage;
466  }
467 
468  conf.upages = (conf.npage*80)/100;
469  conf.ialloc = ((conf.npage-conf.upages)/2)*BY2PG;
470 
471  /* only one processor */
472  conf.nmach = 1;
473 
474  /* set up other configuration parameters */
475  conf.nproc = 100 + ((conf.npage*BY2PG)/MB)*5;
476  if(cpuserver)
477  conf.nproc *= 3;
478  if(conf.nproc > 2000)
479  conf.nproc = 2000;
480  conf.nswap = conf.npage*3;
481  conf.nswppo = 4096;
482  conf.nimage = 200;
483 
484  conf.copymode = 0; /* copy on write */
485 
486  /*
487  * Guess how much is taken by the large permanent
488  * datastructures. Mntcache and Mntrpc are not accounted for
489  * (probably ~300KB).
490  */
491  kpages = conf.npage - conf.upages;
492  kpages *= BY2PG;
493  kpages -= conf.upages*sizeof(Page)
494  + conf.nproc*sizeof(Proc)
495  + conf.nimage*sizeof(Image)
496  + conf.nswap
497  + conf.nswppo*sizeof(Page);
498  mainmem->maxsize = kpages;
499  if(!cpuserver)
500  /*
501  * give terminals lots of image memory, too; the dynamic
502  * allocation will balance the load properly, hopefully.
503  * be careful with 32-bit overflow.
504  */
505  imagmem->maxsize = kpages;
506 
507 }
508 
509 static void
510 shutdown(int ispanic)
511 {
512  int ms, once;
513 
514  lock(&active);
515  if(ispanic)
516  active.ispanic = ispanic;
517  else if(m->machno == 0 && (active.machs & (1<<m->machno)) == 0)
518  active.ispanic = 0;
519  once = active.machs & (1<<m->machno);
520  active.machs &= ~(1<<m->machno);
521  active.exiting = 1;
522  unlock(&active);
523 
524  if(once)
525  iprint("cpu%d: exiting\n", m->machno);
526  spllo();
527  for(ms = 5*1000; ms > 0; ms -= TK2MS(2)){
528  delay(TK2MS(2));
529  if(active.machs == 0 && consactive() == 0)
530  break;
531  }
532  delay(1000);
533 }
534 
535 /*
536  * exit kernel either on a panic or user request
537  */
538 void
539 exit(int code)
540 {
541  shutdown(code);
542  splfhi();
543  archreboot();
544 }
545 
546 /*
547  * stub for ../omap/devether.c
548  */
549 int
550 isaconfig(char *class, int ctlrno, ISAConf *isa)
551 {
552  USED(ctlrno);
553  USED(isa);
554  return strcmp(class, "ether") == 0;
555 }
556 
557 /*
558  * the new kernel is already loaded at address `code'
559  * of size `size' and entry point `entry'.
560  */
561 void
562 reboot(void *entry, void *code, ulong size)
563 {
564  void (*f)(ulong, ulong, ulong);
565 
566  print("starting reboot...");
567  writeconf();
568  shutdown(0);
569 
570  /*
571  * should be the only processor running now
572  */
573 
574  print("reboot entry %#lux code %#lux size %ld\n",
575  PADDR(entry), PADDR(code), size);
576  delay(100);
577 
578  /* turn off buffered serial console */
579  serialoq = nil;
580  kprintoq = nil;
581  screenputs = nil;
582 
583  /* shutdown devices */
584  chandevshutdown();
585 
586  /* stop the clock (and watchdog if any) */
587  clockshutdown();
588 
589  splfhi();
590  intrsoff();
591 
592  /* setup reboot trampoline function */
593  f = (void*)REBOOTADDR;
594  memmove(f, rebootcode, sizeof(rebootcode));
595  cacheuwbinv();
596 
597  /* off we go - never to return */
598  (*f)(PADDR(entry), PADDR(code), size);
599 
600  iprint("loaded kernel returned!\n");
601  delay(1000);
602  archreboot();
603 }
604 
605 int
606 cmpswap(long *addr, long old, long new)
607 {
608  return cas32(addr, old, new);
609 }