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#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/uio.h>
#include <sys/wait.h>
static void write_str(int fd, const char* str)
{
write(fd, str, __builtin_strlen(str));
}
static void error(const char* message)
{
// Attempt to spew to kernel log
int kmfd = open("/dev/kmsg", O_WRONLY | O_CLOEXEC);
if (kmfd >= 0) {
write_str(kmfd, message);
close(kmfd);
}
_exit(1); // Kernel panic
}
#define ERROR(message) error("[rlinit] " message)
static bool mount_required(const char* src, const char* tgt, const char* fs)
{
// EBUSY means already mounted, which is ok
return mount(src, tgt, fs, 0, 0) >= 0 || errno == EBUSY;
}
int main(void)
{
#if 0
// First, spew a message to tty to signal we at least made it this far
{
const char* hello = "rlinit: Initialization started\n";
write(1, hello, __builtin_strlen(hello));
}
#endif
// Mount /dev first, as /dev/kmsg is useful for debugging errors
// @@ include errno in error messages
if (!mount_required("devtmpfs", "/dev", "devtmpfs")) {
ERROR("Failed to mount /dev\n");
}
if (!mount_required("proc", "/proc", "proc")) {
ERROR("Failed to mount /proc\n");
}
if (!mount_required("sysfs", "/sys", "sysfs")) {
ERROR("Failed to mount /sys\n");
}
// Write to kernel log
{
int kmfd = open("/dev/kmsg", O_WRONLY | O_CLOEXEC);
if (kmfd >= 0) {
const char* hello = "<6>Rushmore Linux - Nothing is beyond our reach.\n";
write(kmfd, hello, __builtin_strlen(hello));
close(kmfd);
}
}
// pid_t pid = fork();
// if (pid == 0) {
// char *argv[] = { (char*)"/rlwsd", 0 };
// execv(argv[0], argv);
// _exit(127);
// }
// int st = 0;
// waitpid(pid, &st, 0);
// write(1, "rlinit: rlwsd exited\n", 21);
for (;;) pause();
}
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