ref: 839f58e99af49deaa14da76a10635086175145d6
dir: /sys/src/9/port/rebootcmd.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "a.out.h" static void readn(Chan *c, void *vp, long n) { char *p = vp; long nn; while(n > 0) { nn = devtab[c->type]->read(c, p, n, c->offset); if(nn == 0) error(Eshort); c->offset += nn; p += nn; n -= nn; } } void rebootcmd(int argc, char *argv[]) { struct { Exec; uvlong hdr[1]; } ehdr; Chan *c; ulong magic, text, rtext, entry, data, size, align; uchar *p; if(argc == 0) exit(0); c = namec(argv[0], Aopen, OEXEC, 0); if(waserror()){ cclose(c); nexterror(); } readn(c, &ehdr, sizeof(Exec)); magic = beswal(ehdr.magic); entry = beswal(ehdr.entry); text = beswal(ehdr.text); data = beswal(ehdr.data); if(!(magic == AOUT_MAGIC)){ switch(magic){ case I_MAGIC: case S_MAGIC: if((I_MAGIC == AOUT_MAGIC) || (S_MAGIC == AOUT_MAGIC)) break; default: error(Ebadexec); } } if(magic & HDR_MAGIC) readn(c, ehdr.hdr, sizeof(ehdr.hdr)); switch(magic){ case R_MAGIC: align = 0x10000; /* 64k segment alignment for arm64 */ break; default: align = BY2PG; break; } /* round text out to page boundary */ rtext = ROUND(entry+text, align)-entry; size = rtext + data; p = malloc(size); if(p == nil) error(Enomem); if(waserror()){ free(p); nexterror(); } memset(p, 0, size); readn(c, p, text); readn(c, p + rtext, data); ksetenv("bootfile", argv[0], 1); reboot((void*)entry, p, size); error(Egreg); }