spkg: Add support package groundwork

Signed-off-by: Chloe M. <chloe@yiffware.org>

service/spkg/Makefile

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2026, Chloe M.
+# Provided under the BSD-3 clause
+#
+# Description:  Support package build script
+# Author:		Chloe M.
+#
+
+include ../mk/ptos.mk
+
+CFILES = $(shell find . -name "*.c")
+OFILES = $(CFILES:.c=.o)
+DFILES = $(CFILES:.c=.d)
+
+CFLAGS = 					\
+	$(SYS_CFLAGS)			\
+	-MMD					\
+	-I$(PT_PROJECT_ROOT)/sdk/head
+
+.PHONY: all
+all: $(OFILES)
+
+-include $(DFILES)
+%.o: %.c
+	$(PROMPT) "CC" $<
+	$(SYS_CC) -c $(CFLAGS) $< -o $@

service/spkg/head/string.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2026, Chloe M., et al
+ * Provided under the BSD-3 clause.
+ *
+ * Description:  String libraries
+ * Author:       Chloe M.
+ */
+
+#ifndef _SPKG_STRING_H_
+#define _SPKG_STRING_H_ 1
+
+#include <ptdef.h>
+
+/*
+ * Obtain the length of a string
+ *
+ * @String:  String to obtain length of
+ */
+USIZE RtlStrLen(const CHAR *String);
+
+#endif  /* !_SPKG_STRING_H_ */

service/spkg/strlib/strlen.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2026, Chloe M., et al
+ * Provided under the BSD-3 clause.
+ *
+ * Description:  Obtain length of string
+ * Author:       Chloe M.
+ */
+
+#include <ptdef.h>
+
+USIZE
+RtlStrLen(const CHAR *String)
+{
+    USIZE Length = 0;
+
+    if (String == NULL) {
+        return 0;
+    }
+
+    while (String[Length++] != '\0');
+    return Length;
+}