ref: b502a62da2ec6058923db94f87ecc2d29db2fa77
dir: /os/boot.original/puma/plan9boot.c/
#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" char *premature = "premature EOF\n"; /* * read in a segment */ static long readseg(int dev, long (*read)(int, void*, long), long len, long addr) { char *a; long n, sofar; a = (char *)addr; for(sofar = 0; sofar < len; sofar += n){ n = 8*1024; if(len - sofar < n) n = len - sofar; n = (*read)(dev, a + sofar, n); if(n <= 0) break; print("."); } return sofar; } /* * boot */ int plan9boot(int dev, long (*seek)(int, long), long (*read)(int, void*, long)) { long n; long addr; void (*b)(void); Exec *ep; if((*seek)(dev, 0) < 0) return -1; /* * read header */ ep = (Exec *) ialloc(sizeof(Exec), 0); n = sizeof(Exec); if(readseg(dev, read, n, (ulong) ep) != n){ print(premature); return -1; } if(GLLONG(ep->magic) != E_MAGIC){ print("bad magic 0x%lux not a plan 9 executable!\n", GLLONG(ep->magic)); return -1; } /* * read text */ addr = PADDR(GLLONG(ep->entry)); n = GLLONG(ep->text); print("%d", n); if(readseg(dev, read, n, addr) != n){ print(premature); return -1; } /* * read data (starts at first page after kernel) */ addr = PGROUND(addr+n); n = GLLONG(ep->data); print("+%d", n); if(readseg(dev, read, n, addr) != n){ print(premature); return -1; } /* * bss and entry point */ print("+%d\nstart at 0x%lux\n", GLLONG(ep->bss), GLLONG(ep->entry)); uartwait(); /* * Go to new code. It's up to the program to get its PC relocated to * the right place. */ b = (void (*)(void))(PADDR(GLLONG(ep->entry))); (*b)(); return 0; }