stdlib: add missing features to build PolarSSL

This patch adds the missing features to the C library included
in the Trusted Firmware to build PolarSSL:

  - strcasecmp() function
  - exit() function
  - sscanf()* function
  - time.h header file (and its dependencies)

* NOTE: the sscanf() function is not a real implementation. It just
returns the number of expected arguments by counting the number of
'%' characters present in the formar string. This return value is
good enough for PolarSSL because during the certificate parsing
only the return value is checked. The certificate validity period
is ignored.

Change-Id: I43bb3742f26f0bd458272fccc3d72a7f2176ab3d

4 files changed, 104 insertions, 0 deletions

diff --git a/lib/stdlib/exit.c b/lib/stdlib/exit.c
new file mode 100644
index 00000000..3e775914
--- /dev/null
+++ b/lib/stdlib/exit.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <debug.h>
+
+void exit(int v)
+{
+	ERROR("EXIT\n");
+	panic();
+}
diff --git a/lib/stdlib/sscanf.c b/lib/stdlib/sscanf.c
new file mode 100644
index 00000000..e9f5c4a1
--- /dev/null
+++ b/lib/stdlib/sscanf.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+
+/*
+ * TODO: This is not a real implementation of the sscanf() function. It just
+ * returns the number of expected arguments based on the number of '%' found
+ * in the format string.
+ */
+int
+sscanf(const char *__restrict str, char const *__restrict fmt, ...)
+{
+	int ret = 0;
+
+	while (*fmt != '\0') {
+		if (*fmt++ == '%') {
+			ret++;
+		}
+	}
+
+	return ret;
+}
diff --git a/lib/stdlib/std.c b/lib/stdlib/std.c
index 46087549..5f6ef752 100644
--- a/lib/stdlib/std.c
+++ b/lib/stdlib/std.c
@@ -32,10 +32,12 @@
 /* Include the various implemented functions */
 #include "abort.c"
 #include "assert.c"
+#include "exit.c"
 #include "mem.c"
 #include "printf.c"
 #include "putchar.c"
 #include "puts.c"
+#include "sscanf.c"
 #include "strchr.c"
 #include "strcmp.c"
 #include "strlen.c"
diff --git a/lib/stdlib/strcmp.c b/lib/stdlib/strcmp.c
index 1d26f2bd..bb86e0f2 100644
--- a/lib/stdlib/strcmp.c
+++ b/lib/stdlib/strcmp.c
@@ -36,6 +36,7 @@
  */
 
 #include <sys/cdefs.h>
+#include <sys/ctype.h>
 #include <string.h>
 
 /*
@@ -49,3 +50,17 @@ strcmp(const char *s1, const char *s2)
 			return 0;
 	return *(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1);
 }
+
+int
+strcasecmp(const char *s1, const char *s2)
+{
+	const unsigned char *us1 = (const unsigned char *)s1;
+	const unsigned char *us2 = (const unsigned char *)s2;
+
+	while (tolower(*us1) == tolower(*us2)) {
+		if (*us1++ == '\0')
+			return 0;
+		us2++;
+	}
+	return tolower(*us1) - tolower(*us2);
+}