Patch to automatically spawn agetty on kernel consoles

The feature is useful for developers and admins that occasionally need
to boot with e.g. console=ttyS0.
The built in default can be overridden via inittab for each device. An
entry like "S0::off:" turns off the getty on ttyS0.
This commit is contained in:
Jesse Smith 2018-02-20 19:18:58 -04:00
parent e80878c555
commit 6e3e87bf32

View File

@ -1291,6 +1291,76 @@ void startup(CHILD *ch)
} }
} }
#ifdef __linux__
static
void check_kernel_console()
{
FILE* fp;
char buf[4096];
if ((fp = fopen("/proc/cmdline", "r")) == 0) {
return;
}
if (fgets(buf, sizeof(buf), fp)) {
char* p = buf;
while ((p = strstr(p, "console="))) {
char* e;
p += strlen("console=");
for (e = p; *e; ++e) {
switch (*e) {
case '-' ... '9':
case 'A' ... 'Z':
case '_':
case 'a' ... 'z':
continue;
}
break;
}
if (p != e) {
CHILD* old;
int dup = 0;
char id[8] = {0};
char dev[32] = {0};
strncpy(dev, p, MIN(sizeof(dev), (unsigned)(e-p)));
if (!strncmp(dev, "tty", 3))
strncpy(id, dev+3, sizeof(id));
else
strncpy(id, dev, sizeof(id));
for(old = newFamily; old; old = old->next) {
if (!strcmp(old->id, id)) {
dup = 1;
}
}
if (!dup) {
CHILD* ch = imalloc(sizeof(CHILD));
ch->action = RESPAWN;
strcpy(ch->id, id);
strcpy(ch->rlevel, "2345");
sprintf(ch->process, "/sbin/agetty -L -s 115200,38400,9600 %s vt102", dev);
ch->next = NULL;
for(old = family; old; old = old->next) {
if (strcmp(old->id, ch->id) == 0) {
old->new = ch;
break;
}
}
/* add to end */
for(old = newFamily; old; old = old->next) {
if (!old->next) {
old->next = ch;
break;
}
}
initlog(L_VB, "added agetty on %s with id %s", dev, id);
}
}
}
}
fclose(fp);
return;
}
#endif
/* /*
* Read the inittab file. * Read the inittab file.
@ -1503,6 +1573,10 @@ void read_inittab(void)
*/ */
if (fp) fclose(fp); if (fp) fclose(fp);
#ifdef __linux__
check_kernel_console();
#endif
/* /*
* Loop through the list of children, and see if they need to * Loop through the list of children, and see if they need to
* be killed. * be killed.