dev(sell): add simple libc and implement shell

please see the log for detail.

1 files changed, 31 insertions, 0 deletions

diff --git a/include/ulib/errno.h b/include/ulib/errno.h
new file mode 100644
index 0000000..03ff8fd
--- /dev/null
+++ b/include/ulib/errno.h
@@ -0,0 +1,31 @@
+#ifndef _ERRNO_H
+#define _ERRNO_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+extern int errno;
+
+// Linux/ASM-Generic
+#define EPERM 1   /* Operation not permitted */
+#define ENOENT 2  /* No such file or directory */
+#define ESRCH 3   /* No such process */
+#define EINTR 4   /* Interrupted system call */
+#define EIO 5     /* I/O error */
+#define ENXIO 6   /* No such device or address */
+#define E2BIG 7   /* Argument list too long */
+#define ENOEXEC 8 /* Exec format error */
+#define EBADF 9   /* Bad file number */
+#define ECHILD 10 /* No child processes */
+#define EAGAIN 11 /* Try again */
+#define ENOMEM 12 /* Out of memory */
+#define EACCES 13 /* Permission denied */
+#define EFAULT 14 /* Bad address */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
\ No newline at end of file