From 090e97e3e17689bd6a7b3b1aa743de852cd0a8d0 Mon Sep 17 00:00:00 2001
From: Francesco <inbox@francescorocca.me>
Date: Mon, 26 Jan 2026 15:22:46 +0100
Subject: [PATCH] feat(memory, string): add memory and string utilities

---
 include/memory.h | 10 ++++++++++
 include/string.h | 15 +++++++++++++++
 run.sh           |  4 +++-
 src/kernel.c     | 21 ++++++---------------
 src/memory.c     | 21 +++++++++++++++++++++
 src/string.c     | 29 +++++++++++++++++++++++++++++
 6 files changed, 84 insertions(+), 16 deletions(-)
 create mode 100644 include/memory.h
 create mode 100644 include/string.h
 create mode 100644 src/memory.c
 create mode 100644 src/string.c

diff --git a/include/memory.h b/include/memory.h
new file mode 100644
index 0000000..ea6f8f0
--- /dev/null
+++ b/include/memory.h
@@ -0,0 +1,10 @@
+#ifndef RIVOS_MEMORY_H
+#define RIVOS_MEMORY_H
+
+#include "types.h"
+
+void *kmemset(void *buf, char c, size_t n);
+
+void *kmemcpy(void *dst, const void *src, size_t n);
+
+#endif
diff --git a/include/string.h b/include/string.h
new file mode 100644
index 0000000..7b5babd
--- /dev/null
+++ b/include/string.h
@@ -0,0 +1,15 @@
+#ifndef RIVOS_STRING_H
+#define RIVOS_STRING_H
+
+#include "types.h"
+
+/**
+ * This is not a safe function, check dst size
+ */
+char *kstrcpy(char *dst, const char *src);
+
+size_t kstrlen(const char *str);
+
+int kstrcmp(const char *s1, const char *s2);
+
+#endif
diff --git a/run.sh b/run.sh
index bc52bf0..fa545d6 100755
--- a/run.sh
+++ b/run.sh
@@ -18,7 +18,9 @@ CFLAGS="-std=c11 -O2 -g3 -Wall -Wextra --target=riscv32-unknown-elf -fuse-ld=lld
 
 $CC $CFLAGS -Wl,-Tkernel.ld -Wl,-Map=kernel.map -o kernel.elf \
     src/kernel.c \
-    src/io.c
+    src/io.c \
+    src/memory.c \
+    src/string.c
 
 # Run QEMU
 # -machine virt: generic riscv platform
diff --git a/src/kernel.c b/src/kernel.c
index ef03ff3..7aa5f89 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -1,6 +1,6 @@
 #include "../include/kernel.h"
 #include "../include/io.h"
-#include "../include/types.h"
+#include "../include/memory.h"
 
 extern char __bss[], __bss_end[], __stack_top[];
 
@@ -14,7 +14,7 @@ extern char __bss[], __bss_end[], __stack_top[];
  * a0 returns and error code
  */
 sbiret_s sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long arg5, long fid, long eid) {
-	register long a0 __asm("a0") = arg0;
+	register long a0 __asm__("a0") = arg0;
 	register long a1 __asm__("a1") = arg1;
 	register long a2 __asm__("a2") = arg2;
 	register long a3 __asm__("a3") = arg3;
@@ -31,27 +31,18 @@ sbiret_s sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4, long ar
 	return (sbiret_s){.error = a0, .value = a1};
 }
 
-void k_putchar(char ch) {
+void kputchar(char ch) {
 	sbi_call(ch, 0, 0, 0, 0, 0, 0, 1);
 }
 
-void *k_memset(void *buf, char c, size_t n) {
-	u8 *p = (u8 *)buf;
-	while (n--) {
-		*p++ = c;
-	}
-
-	return buf;
-}
-
 /* Kernel main */
 void kernel_main(void) {
 	/* Usually it is not required */
-	k_memset(__bss, 0, __bss_end - __bss);
+	kmemset(__bss, 0, __bss_end - __bss);
 
 	/* Start here */
-	r_printf("%s, %s\n", "Hello", "world!");
-	r_printf("3 + 4 = %d\n", 3 + 4);
+	kprintf("%s, %s\n", "Hello", "world!");
+	kprintf("3 + 4 = %d\n", 3 + 4);
 
 	for (;;) {
 		__asm__ __volatile__("wfi");
diff --git a/src/memory.c b/src/memory.c
new file mode 100644
index 0000000..5ffd617
--- /dev/null
+++ b/src/memory.c
@@ -0,0 +1,21 @@
+#include "../include/memory.h"
+
+void *kmemset(void *buf, char c, size_t n) {
+	u8 *p = (u8 *)buf;
+	while (n--) {
+		*p++ = c;
+	}
+
+	return buf;
+}
+
+void *kmemcpy(void *dst, const void *src, size_t n) {
+	u8 *dest = (u8 *)dst;
+	const u8 *source = (u8 *)src;
+
+	while (n--) {
+		*dest++ = *source++;
+	}
+
+	return dst;
+}
diff --git a/src/string.c b/src/string.c
new file mode 100644
index 0000000..e8c15a5
--- /dev/null
+++ b/src/string.c
@@ -0,0 +1,29 @@
+#include "../include/string.h"
+
+char *kstrcpy(char *dst, const char *src) {
+	while (*src) {
+		*dst = *src;
+		src++;
+	}
+
+	return dst;
+}
+
+size_t kstrlen(const char *str) {
+	size_t len = 0;
+
+	while (*str) {
+		len++;
+		str++;
+	}
+
+	return len;
+}
+
+int kstrcmp(const char *s1, const char *s2) {
+	/**
+	 * TODO
+	 */
+
+	return 0;
+}