From e0fa180c4b80a2cdd834c823306e9beb438f39ad Mon Sep 17 00:00:00 2001
From: Matthias Kruk <m@m10k.eu>
Date: Sat, 15 Aug 2020 15:15:40 +0900
Subject: [PATCH] libc: Add strerror() implementation

---
 include/string.h |  1 +
 libc/string.c    | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/include/string.h b/include/string.h
index 9697603..536b54b 100644
--- a/include/string.h
+++ b/include/string.h
@@ -6,5 +6,6 @@
 void* memset(void *dst, int val, u32_t n);
 void* memcpy(void *dst, const void *src, u32_t n);
 size_t strlen(const char*);
+const char *strerror(int);
 
 #endif /* _STRING_H */
diff --git a/libc/string.c b/libc/string.c
index a8e548a..566a222 100644
--- a/libc/string.c
+++ b/libc/string.c
@@ -1,4 +1,5 @@
 #include <sys/types.h>
+#include <errno.h>
 
 size_t strlen(const char *s)
 {
@@ -22,3 +23,39 @@ void *memset(void *s, int c, size_t n)
 
 	return(s);
 }
+
+static const char *_errno_str[] = {
+	"SUCCESS",
+	"EINVAL",
+	"ENOSYS",
+	"EALREADY",
+	"EAGAIN",
+	"ENOMEM",
+	"EFAULT",
+	"EAFNOSUPPORT",
+	"EMFILE",
+	"EBADF",
+	"ENFILE",
+	"EADDRNOTAVAIL",
+	"ENOTSUP",
+	"EOPNOTSUPP",
+	"ENOENT",
+	"EPERM",
+	"EACCES",
+	"ERANGE",
+	"EBADFD",
+	"EBUSY",
+	"EINTR",
+	"EOVERFLOW",
+	"ECONNREFUSED",
+	NULL
+};
+
+const char *strerror(int err)
+{
+	if(err < 0 || err > ECONNREFUSED) {
+		err = ECONNREFUSED + 1;
+	}
+
+	return(_errno_str[err]);
+}
-- 
2.47.3