plan9fox/sys/src/9/port/rebootcmd.c
2011-12-12 19:17:58 +01:00

98 lines
1.5 KiB
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 ulong
l2be(long l)
{
uchar *cp;
cp = (uchar*)&l;
return (cp[0]<<24) | (cp[1]<<16) | (cp[2]<<8) | cp[3];
}
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;
}
}
static void
setbootcmd(int argc, char *argv[])
{
char *buf, *p, *ep;
int i;
p = buf = smalloc(1024);
ep = buf + 1024;
for(i=0; i<argc; i++)
p = seprint(p, ep, "%q ", argv[i]);
*p = 0;
ksetenv("bootcmd", buf, 1);
free(buf);
}
void
rebootcmd(int argc, char *argv[])
{
Chan *c;
Exec exec;
ulong magic, text, rtext, entry, data, size;
uchar *p;
if(argc == 0)
exit(0);
c = namec(argv[0], Aopen, OEXEC, 0);
if(waserror()){
cclose(c);
nexterror();
}
readn(c, &exec, sizeof(Exec));
magic = l2be(exec.magic);
entry = l2be(exec.entry);
text = l2be(exec.text);
data = l2be(exec.data);
if(magic != AOUT_MAGIC)
error(Ebadexec);
/* round text out to page boundary */
rtext = PGROUND(entry+text)-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);
setbootcmd(argc-1, argv+1);
reboot((void*)entry, p, size);
panic("return from reboot!");
}