diff --git a/.gitignore b/.gitignore
index 1383201..b2ad23e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,4 +20,3 @@ user/usys.S
 .cache
 compile_commands.json
 tags
-toolchain
diff --git a/Makefile b/Makefile
index 716b923..9ac5771 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,4 @@
-# TOOLPREFIX = riscv64-linux-gnu
-# TOOLPREFIX = toolchain/xpack-riscv-none-elf-gcc-14.2.0-3/bin/riscv-none-elf
-TOOLPREFIX = toolchain/gcc/bin/riscv-none-elf
+TOOLPREFIX = riscv-none-elf
 
 CC = $(TOOLPREFIX)-gcc
 AS = $(TOOLPREFIX)-as
@@ -19,32 +17,25 @@ CFLAGS += -mcmodel=medany
 CFLAGS += -march=rv64gc -mabi=lp64
 CFLAGS += -ffreestanding -fno-common -nostdlib -mno-relax
 
+CFLAGS += -I.
+CFLAGS += -Ilib
+CFLAGS += -Ikern
+
 CFLAGS += -fno-stack-protector # Prevents code that needs libc / runtime support
 CFLAGS += -MD # Generate header dependency files (.d)
 CFLAGS += -fno-pie -no-pie # Fixed address linking
 CFLAGS += -ggdb -gdwarf-2 # GDB debug info
 CFLAGS += -fno-omit-frame-pointer # More reliable backtraces in GDB
 
-KCFLAGS += $(CGFLAGS)
-KCFLAGS += -DNEPTUNE_KERNEL
-KCFLAGS += -Ikern
-KCFLAGS += -Ikern/libkern
-KCFLAGS += -I.
-
-CFLAGS += -I.
-CFLAGS += -Ilib
-
 all: kernel.elf
 
-main: main.o
-
-kernel.elf: entry.o start.o kern/libkern/string.o kern/libkern/proc.o kern/libkern/uart.o kern/libkern/panic.o kern/kalloc.o kern/libkern/memory.o kern/ispinlock.o kern/libkern/spinlock.o kern/libkern/string.o kern/libkern/mini-printf.o
+kernel.elf: entry.o start.o lib/string.o lib/proc.o lib/proc.o lib/uart.o lib/panic.o kern/kalloc.o lib/memory.o kern/ispinlock.o lib/spinlock.o
 	@echo LD $@
 	@$(LD) $(LDFLAGS) -o $@ $^
 
 %.o: %.c
 	@echo CC $@
-	@$(CC) $(KCFLAGS) -nostdinc -I. -c $< -o $@
+	@$(CC) $(CFLAGS) -nostdinc -I. -c $< -o $@
 
 %.o: %.S
 	@echo AS $@
@@ -56,62 +47,7 @@ qemu: kernel.elf
 
 clean:
 	rm -f *.o *.elf *.d lib/*.o lib/*.d
-	fd -e o -x rm # TODO: Should only depend on posix
 
 -include *.d
 
-# --------------------------------------------------------------------
-# Toolchain configuration
-# --------------------------------------------------------------------
-
-TOOLCHAIN_DIR := toolchain
-
-# Versions
-QEMU_VER := 8.2.6-1
-GCC_VER  := 14.2.0-3
-
-# Filenames
-QEMU_TARBALL := xpack-qemu-riscv-$(QEMU_VER)-linux-arm.tar.gz
-GCC_TARBALL  := xpack-riscv-none-elf-gcc-$(GCC_VER)-linux-arm.tar.gz
-
-# URLs
-QEMU_URL := https://github.com/xpack-dev-tools/qemu-riscv-xpack/releases/download/v$(QEMU_VER)/$(QEMU_TARBALL)
-GCC_URL  := https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases/download/v$(GCC_VER)/$(GCC_TARBALL)
-
-# Paths
-QEMU_TARPATH := toolchain/xpack-qemu-riscv-8.2.6-1-linux-arm.tar.gz
-GCC_TARPATH := toolchain/xpack-riscv-none-elf-gcc-14.2.0-3-linux-arm.tar.gz
-
-# Extracted directories
-QEMU_DIR := $(TOOLCHAIN_DIR)/xpack-qemu-riscv-$(QEMU_VER)
-GCC_DIR  := $(TOOLCHAIN_DIR)/xpack-riscv-none-elf-gcc-$(GCC_VER)
-
-# Symlink targets
-QEMU_SYM_DIR := xpack-qemu-riscv-$(QEMU_VER)
-GCC_SYM_DIR  := xpack-riscv-none-elf-gcc-$(GCC_VER)
-
-# Final symlink/alias
-GCC_ALIAS := gcc
-QEMU_ALIAS := qemu
-
-QEMU_TARPATH:
-	curl -# -L -o $@ $(QEMU_URL)
-
-GCC_TARPATH:
-	curl -# -L -o $@ $(GCC_URL)
-
-extractions:
-	cd toolchain && tar xf $(QEMU_TARBALL)
-	cd toolchain && tar xf $(GCC_TARBALL)
-
-toolchain: $(QEMU_TARPATH) $(GCC_TARPATH)
-	mkdir -p toolchain
-	cd toolchain && tar xf $(QEMU_TARBALL)
-	cd toolchain && tar xf $(GCC_TARBALL)
-	cd $(TOOLCHAIN_DIR) && ln -sfn $(QEMU_SYM_DIR) $(QEMU_ALIAS)
-	cd $(TOOLCHAIN_DIR) && ln -sfn $(GCC_SYM_DIR)  $(GCC_ALIAS)
-
-distclean: clean
-	rm -rf $(TOOLCHAIN_DIR)
-
-.PHONY: all toolchain
+.PHONY: all
diff --git a/kern/ispinlock.h b/kern/ispinlock.h
index e30d4b6..d71af17 100644
--- a/kern/ispinlock.h
+++ b/kern/ispinlock.h
@@ -1,5 +1,5 @@
 #pragma once
-#include <stdint.h>
+#include <types.h>
 
 typedef struct {
     volatile uint32_t v; // 0 = unlocked, 1 = locked
diff --git a/kern/libkern/mini-printf.c b/kern/libkern/mini-printf.c
deleted file mode 100644
index ec0ff14..0000000
--- a/kern/libkern/mini-printf.c
+++ /dev/null
@@ -1,311 +0,0 @@
-/*
- * The Minimal snprintf() implementation
- *
- * Copyright (c) 2013,2014 Michal Ludvig <michal@logix.cz>
- * 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 the auhor 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 AUTHOR 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.
- *
- * ----
- *
- * This is a minimal snprintf() implementation optimised
- * for embedded systems with a very limited program memory.
- * mini_snprintf() doesn't support _all_ the formatting
- * the glibc does but on the other hand is a lot smaller.
- * Here are some numbers from my STM32 project (.bin file size):
- *      no snprintf():      10768 bytes
- *      mini snprintf():    11420 bytes     (+  652 bytes)
- *      glibc snprintf():   34860 bytes     (+24092 bytes)
- * Wasting nearly 24kB of memory just for snprintf() on
- * a chip with 32kB flash is crazy. Use mini_snprintf() instead.
- *
- */
-
-#include "mini-printf.h"
-
-static int
-mini_strlen(const char *s)
-{
-	int len = 0;
-	while (s[len] != '\0') len++;
-	return len;
-}
-
-static int
-mini_itoa(long value, unsigned int radix, int uppercase, int unsig,
-	 char *buffer)
-{
-	char	*pbuffer = buffer;
-	int	negative = 0;
-	int	i, len;
-
-	/* No support for unusual radixes. */
-	if (radix > 16)
-		return 0;
-
-	if (value < 0 && !unsig) {
-		negative = 1;
-		value = -value;
-	}
-
-	/* This builds the string back to front ... */
-	do {
-		int digit = value % radix;
-		*(pbuffer++) = (digit < 10 ? '0' + digit : (uppercase ? 'A' : 'a') + digit - 10);
-		value /= radix;
-	} while (value > 0);
-
-	if (negative)
-		*(pbuffer++) = '-';
-
-	*(pbuffer) = '\0';
-
-	/* ... now we reverse it (could do it recursively but will
-	 * conserve the stack space) */
-	len = (pbuffer - buffer);
-	for (i = 0; i < len / 2; i++) {
-		char j = buffer[i];
-		buffer[i] = buffer[len-i-1];
-		buffer[len-i-1] = j;
-	}
-
-	return len;
-}
-
-static int
-mini_pad(char* ptr, int len, char pad_char, int pad_to, char *buffer)
-{
-	int i;
-	int overflow = 0;
-	char * pbuffer = buffer;
-	if(pad_to == 0) pad_to = len;
-	if(len > pad_to) {
-		len = pad_to;
-		overflow = 1;
-	}
-	for(i = pad_to - len; i > 0; i --) {
-		*(pbuffer++) = pad_char;
-	}
-	for(i = len; i > 0; i --) {
-		*(pbuffer++) = *(ptr++);
-	}
-	len = pbuffer - buffer;
-	if(overflow) {
-		for (i = 0; i < 3 && pbuffer > buffer; i ++) {
-			*(pbuffer-- - 1) = '*';
-		}
-	}
-	return len;
-}
-
-struct mini_buff {
-	char *buffer, *pbuffer;
-	unsigned int buffer_len;
-};
-
-static int
-_puts(char *s, int len, void *buf)
-{
-	if(!buf) return len;
-	struct mini_buff *b = buf;
-	char * p0 = b->buffer;
-	int i;
-	/* Copy to buffer */
-	for (i = 0; i < len; i++) {
-		if(b->pbuffer == b->buffer + b->buffer_len - 1) {
-			break;
-		}
-		*(b->pbuffer ++) = s[i];
-	}
-	*(b->pbuffer) = 0;
-	return b->pbuffer - p0;
-}
-
-#ifdef MINI_PRINTF_ENABLE_OBJECTS
-static int (*mini_handler) (void* data, void* obj, int ch, int lhint, char** bf) = 0;
-static void (*mini_handler_freeor)(void* data, void*) = 0;
-static void * mini_handler_data = 0;
-
-void mini_printf_set_handler(
-	void* data,
-	int (*handler)(void* data, void* obj, int ch, int len_hint, char** buf),
-	void (*freeor)(void* data, void* buf))
-{
-	mini_handler = handler;
-	mini_handler_freeor = freeor;
-	mini_handler_data = data;
-}
-#endif
-
-int
-mini_vsnprintf(char *buffer, unsigned int buffer_len, const char *fmt, va_list va)
-{
-	struct mini_buff b;
-	b.buffer = buffer;
-	b.pbuffer = buffer;
-	b.buffer_len = buffer_len;
-	if(buffer_len == 0) buffer = (void*) 0;
-	int n = mini_vpprintf(_puts, (buffer != (void*)0)?&b:(void*)0, fmt, va);
-	if(buffer == (void*) 0) {
-		return n;
-	}
-	return b.pbuffer - b.buffer;
-}
-
-int
-mini_vpprintf(int (*puts)(char* s, int len, void* buf), void* buf, const char *fmt, va_list va)
-{
-	char bf[24];
-	char bf2[24];
-	char ch;
-#ifdef MINI_PRINTF_ENABLE_OBJECTS
-	void* obj;
-#endif
-	if(puts == (void*)0) {
-		/* run puts in counting mode. */
-		puts = _puts; buf = (void*)0;
-	}
-	int n = 0;
-	while ((ch=*(fmt++))) {
-		int len;
-		if (ch!='%') {
-			len = 1;
-			len = puts(&ch, len, buf);
-		} else {
-			char pad_char = ' ';
-			int pad_to = 0;
-			char l = 0;
-			char *ptr;
-
-			ch=*(fmt++);
-
-			/* Zero padding requested */
-			if (ch == '0') pad_char = '0';
-			while (ch >= '0' && ch <= '9') {
-				pad_to = pad_to * 10 + (ch - '0');
-				ch=*(fmt++);
-			}
-			if(pad_to > (signed int) sizeof(bf)) {
-				pad_to = sizeof(bf);
-			}
-			if (ch == 'l') {
-				l = 1;
-				ch=*(fmt++);
-			}
-
-			switch (ch) {
-				case 0:
-					goto end;
-				case 'u':
-				case 'd':
-					if(l) {
-						len = mini_itoa(va_arg(va, unsigned long), 10, 0, (ch=='u'), bf2);
-					} else {
-						if(ch == 'u') {
-							len = mini_itoa((unsigned long) va_arg(va, unsigned int), 10, 0, 1, bf2);
-						} else {
-							len = mini_itoa((long) va_arg(va, int), 10, 0, 0, bf2);
-						}
-					}
-					len = mini_pad(bf2, len, pad_char, pad_to, bf);
-					len = puts(bf, len, buf);
-					break;
-
-				case 'x':
-				case 'X':
-					if(l) {
-						len = mini_itoa(va_arg(va, unsigned long), 16, (ch=='X'), 1, bf2);
-					} else {
-						len = mini_itoa((unsigned long) va_arg(va, unsigned int), 16, (ch=='X'), 1, bf2);
-					}
-					len = mini_pad(bf2, len, pad_char, pad_to, bf);
-					len = puts(bf, len, buf);
-					break;
-
-				case 'c' :
-					ch = (char)(va_arg(va, int));
-					len = mini_pad(&ch, 1, pad_char, pad_to, bf);
-					len = puts(bf, len, buf);
-					break;
-
-				case 's' :
-					ptr = va_arg(va, char*);
-					len = mini_strlen(ptr);
-					if (pad_to > 0) {
-						len = mini_pad(ptr, len, pad_char, pad_to, bf);
-						len = puts(bf, len, buf);
-					} else {
-						len = puts(ptr, len, buf);
-					}
-					break;
-#ifdef MINI_PRINTF_ENABLE_OBJECTS
-				case 'O' :  /* Object by content (e.g. str) */
-				case 'R' :  /* Object by representation (e.g. repr)*/
-					obj = va_arg(va, void*);
-					len = mini_handler(mini_handler_data, obj, ch, pad_to, &ptr);
-					if (pad_to > 0) {
-						len = mini_pad(ptr, len, pad_char, pad_to, bf);
-						len = puts(bf, len, buf);
-					} else {
-						len = puts(ptr, len, buf);
-					}
-					mini_handler_freeor(mini_handler_data, ptr);
-					break;
-#endif
-				default:
-					len = 1;
-					len = puts(&ch, len, buf);
-					break;
-			}
-		}
-		n = n + len;
-	}
-end:
-	return n;
-}
-
-
-int
-mini_snprintf(char* buffer, unsigned int buffer_len, const char *fmt, ...)
-{
-	int ret;
-	va_list va;
-	va_start(va, fmt);
-	ret = mini_vsnprintf(buffer, buffer_len, fmt, va);
-	va_end(va);
-
-	return ret;
-}
-
-int
-mini_pprintf(int (*puts)(char*s, int len, void* buf), void* buf, const char *fmt, ...)
-{
-	int ret;
-	va_list va;
-	va_start(va, fmt);
-	ret = mini_vpprintf(puts, buf, fmt, va);
-	va_end(va);
-
-	return ret;
-}
-
diff --git a/kern/libkern/mini-printf.h b/kern/libkern/mini-printf.h
deleted file mode 100644
index 7667b50..0000000
--- a/kern/libkern/mini-printf.h
+++ /dev/null
@@ -1,73 +0,0 @@
-/*
- * The Minimal snprintf() implementation
- *
- * Copyright (c) 2013 Michal Ludvig <michal@logix.cz>
- * 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 the auhor 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 AUTHOR 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.
- */
-
-
-#ifndef __MINI_PRINTF__
-#define __MINI_PRINTF__
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stdarg.h>
-
-#ifdef MINI_PRINTF_ENABLE_OBJECTS
-/* If enabled, callback for object types (O and R).
- * void* arguments matching %O and %R are sent to handler as obj.
- * the result string created by handler at *buf is freed by freeor.
- * */
-void mini_printf_set_handler(
-	void * data,
-	/* handler returns number of chars in *buf; *buf is not NUL-terminated. */
-	int (*handler)(void* data, void* obj, int ch, int len_hint, char** buf),
-	void (*freeor)(void* data, void* buf));
-#endif
-
-/* String IO interface; returns number of bytes written, not including the ending NUL.
- * Always appends a NUL at the end, therefore buffer_len shall be at least 1 in normal operation.
- * If buffer is NULL or buffer_len is 0, returns number of bytes to be written, not including the ending NUL.
- */
-int mini_vsnprintf(char* buffer, unsigned int buffer_len, const char *fmt, va_list va);
-int mini_snprintf(char* buffer, unsigned int buffer_len, const char *fmt, ...);
-
-/* Stream IO interface; returns number of bytes written.
- * If puts is NULL, number of bytes to be written.
- * puts shall return number of bytes written.
- */
-int mini_vpprintf(int (*puts)(char* s, int len, void* buf), void* buf, const char *fmt, va_list va);
-int mini_pprintf(int (*puts)(char*s, int len, void* buf), void* buf, const char *fmt, ...);
-
-#ifdef __cplusplus
-}
-#endif
-
-#define vsnprintf mini_vsnprintf
-#define snprintf mini_snprintf
-
-#endif
diff --git a/kern/libkern/stdarg.h b/kern/libkern/stdarg.h
deleted file mode 100644
index 1113127..0000000
--- a/kern/libkern/stdarg.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef _STDARG_H
-#define _STDARG_H
-
-typedef __builtin_va_list va_list;
-
-#define va_start(ap, last) __builtin_va_start(ap, last)
-#define va_arg(ap, type)   __builtin_va_arg(ap, type)
-#define va_end(ap)         __builtin_va_end(ap)
-#define va_copy(dest, src) __builtin_va_copy(dest, src)
-
-#endif
diff --git a/kern/libkern/string.c b/kern/libkern/string.c
index e6c0000..99a0ea2 100644
--- a/kern/libkern/string.c
+++ b/kern/libkern/string.c
@@ -114,112 +114,14 @@ void *memset(void *dest, int c, size_t n) {
     return dest;
 }
 
-// int memcmp(const void *s1, const void *s2, size_t n) {
-//     if (n != 0) {
-//         const unsigned char *p1 = s1, *p2 = s2;
-//
-//         do {
-//             if (*p1++ != *p2++)
-//                 return (*--p1 - *--p2);
-//         } while (--n != 0);
-//     }
-//     return (0);
-// }
+int memcmp(const void *s1, const void *s2, size_t n) {
+    if (n != 0) {
+        const unsigned char *p1 = s1, *p2 = s2;
 
-char *itoa(int value, char *str, int base) {
-    char        *p = str;
-    char        *p1, *p2;
-    unsigned int uvalue = value;
-    int          negative = 0;
-
-    if (base < 2 || base > 36) {
-        *str = '\0';
-        return str;
+        do {
+            if (*p1++ != *p2++)
+                return (*--p1 - *--p2);
+        } while (--n != 0);
     }
-
-    if (value < 0 && base == 10) {
-        negative = 1;
-        uvalue = -value;
-    }
-
-    // Convert to string
-    do {
-        int digit = uvalue % base;
-        *p++ = (digit < 10) ? '0' + digit : 'a' + (digit - 10);
-        uvalue /= base;
-    } while (uvalue);
-
-    if (negative)
-        *p++ = '-';
-
-    *p = '\0';
-
-    // Reverse string
-    p1 = str;
-    p2 = p - 1;
-    while (p1 < p2) {
-        char tmp = *p1;
-        *p1++ = *p2;
-        *p2-- = tmp;
-    }
-
-    return str;
-}
-
-// void *memset(void *dst, int c, size_t length) {
-//     u8      *ptr = (u8 *)dst;
-//     const u8 value = (u8)c;
-//
-//     while (length--) *(ptr++) = value;
-//
-//     return dst;
-// }
-
-// void *memcpy(void *dst, const void *src, size_t len) {
-//     u8       *d = (u8 *)dst;
-//     const u8 *s = (const u8 *)src;
-//     for (size_t i = 0; i < len; i++) {
-//         d[i] = s[i];
-//     }
-//     return dst;
-// }
-
-// void *memmove(void *dst, const void *src, size_t len) {
-//     u8       *d = (u8 *)dst;
-//     const u8 *s = (const u8 *)src;
-//     if (d < s) {
-//         for (size_t i = 0; i < len; i++) {
-//             d[i] = s[i];
-//         }
-//     } else if (d > s) {
-//         for (size_t i = len; i > 0; i--) {
-//             d[i - 1] = s[i - 1];
-//         }
-//     }
-//     return dst;
-// }
-
-int memcmp(const void *s1, const void *s2, size_t len) {
-    const u8 *a = (const u8 *)s1;
-    const u8 *b = (const u8 *)s2;
-    for (size_t i = 0; i < len; i++) {
-        if (a[i] != b[i]) {
-            return (int)a[i] - (int)b[i];
-        }
-    }
-    return 0;
-}
-
-size_t strlen(const char *s) {
-    const char *p = s;
-    while (*p) ++p;
-    return (size_t)(p - s);
-}
-
-size_t strnlen(const char *s, size_t maxlen) {
-    size_t len = 0;
-    while (len < maxlen && s[len] != '\0') {
-        len++;
-    }
-    return len;
+    return (0);
 }
diff --git a/kern/libkern/string.h b/kern/libkern/string.h
index d2ff7b5..01d3853 100644
--- a/kern/libkern/string.h
+++ b/kern/libkern/string.h
@@ -1,45 +1,7 @@
-#ifndef KERNEL_STRING_H
-#define KERNEL_STRING_H
+#pragma once
+#include <types.h>
 
-#include <stdint.h>
-
-// void *memcpy(void *s1, const void *s2, size_t n);
-// void *memmove(void *s1, const void *s2, size_t n);
-// void *memset(void *dest, int c, size_t n);
-// int   memcmp(const void *s1, const void *s2, size_t n);
-
-/** Integer to ascii */
-char *itoa(int value, char *str, int base);
-
-/** Fill memory with constant byte */
-void *memset(void *dst, int c, size_t len);
-
-/** Copy `len` bytes from `src` to `dst`. Undefined if regions overlap. */
-void *memcpy(void *dst, const void *src, size_t len);
-
-/** Copy `len` bytes from `src` to `dst`, safe for overlapping regions. */
-void *memmove(void *dst, const void *src, size_t len);
-
-/** Compare `len` bytes of `s1` and `s2`.
- *  Returns 0 if equal, <0 if s1 < s2, >0 if s1 > s2. */
-int memcmp(const void *s1, const void *s2, size_t len);
-
-/** Returns the length of a null-terminated string */
-size_t strlen(const char *s);
-
-/** Return length of string `s`, up to a max of `maxlen` bytes */
-size_t strnlen(const char *s, size_t maxlen);
-
-// TODO: These:
-/*
-int    strcmp(const char *s1, const char *s2);
-int    strncmp(const char *s1, const char *s2, size_t n);
-
-char  *strcpy(char *dst, const char *src);
-char  *strncpy(char *dst, const char *src, size_t n);
-
-char  *strchr(const char *s, int c);
-char  *strrchr(const char *s, int c);
-*/
-
-#endif
+void *memcpy(void *s1, const void *s2, size_t n);
+void *memmove(void *s1, const void *s2, size_t n);
+void *memset(void *dest, int c, size_t n);
+int   memcmp(const void *s1, const void *s2, size_t n);
diff --git a/kern/proc.h b/kern/proc.h
index 26659f3..b594fc9 100644
--- a/kern/proc.h
+++ b/kern/proc.h
@@ -1,6 +1,3 @@
-#include <config.h>
-#include <spinlock.h>
-#include <riscv.h>
 #include <stdint.h>
 
 typedef enum {
@@ -40,7 +37,6 @@ struct Cpu {
     int             intena;  // Were interrupts enabled before push_off()?
 };
 
-/** Saved registers for kernel context switches. */
 typedef struct {
     /*   0 */ uint64_t kernel_satp;   // kernel page table
     /*   8 */ uint64_t kernel_sp;     // top of process's kernel stack
@@ -79,10 +75,3 @@ typedef struct {
     /* 272 */ uint64_t t5;
     /* 280 */ uint64_t t6;
 } TrapFrame_t;
-
-struct Cpu *mycpu(void);
-
-extern struct Cpu cpus[NCPU];
-
-/** Per-process state */
-struct Proc {};
diff --git a/kern/libkern/endian.h b/lib/endian.h
similarity index 100%
rename from kern/libkern/endian.h
rename to lib/endian.h
diff --git a/kern/libkern/memory.c b/lib/memory.c
similarity index 100%
rename from kern/libkern/memory.c
rename to lib/memory.c
diff --git a/kern/libkern/memory.h b/lib/memory.h
similarity index 94%
rename from kern/libkern/memory.h
rename to lib/memory.h
index 01b275a..8a012a2 100644
--- a/kern/libkern/memory.h
+++ b/lib/memory.h
@@ -1,7 +1,7 @@
 #ifndef MEMORY_KERNEL_H
 #define MEMORY_KERNEL_H
 
-#include <stdint.h>
+#include <types.h>
 
 /* These are hardcoded for now */
 #define KERNBASE 0x80000000L
diff --git a/kern/libkern/panic.c b/lib/panic.c
similarity index 100%
rename from kern/libkern/panic.c
rename to lib/panic.c
diff --git a/kern/libkern/panic.h b/lib/panic.h
similarity index 100%
rename from kern/libkern/panic.h
rename to lib/panic.h
diff --git a/kern/libkern/proc.c b/lib/proc.c
similarity index 100%
rename from kern/libkern/proc.c
rename to lib/proc.c
diff --git a/lib/proc.h b/lib/proc.h
new file mode 100644
index 0000000..1208b2b
--- /dev/null
+++ b/lib/proc.h
@@ -0,0 +1,22 @@
+#include <config.h>
+#include <lib/spinlock.h>
+#include <riscv.h>
+#include <types.h>
+
+struct Cpu *mycpu(void);
+
+/** Saved registers for kernel context switches. */
+struct Context {};
+
+/** Per-CPU state. */
+struct Cpu {
+    struct Proc   *proc;    // The process running on this cpu, or null.
+    struct Context context; // swtch() here to enter scheduler().
+    int            noff;    // Depth of push_off() nesting.
+    int            intena;  // Were interrupts enabled before push_off()?
+};
+
+extern struct Cpu cpus[NCPU];
+
+/** Per-process state */
+struct Proc {};
diff --git a/kern/libkern/spinlock.c b/lib/spinlock.c
similarity index 100%
rename from kern/libkern/spinlock.c
rename to lib/spinlock.c
diff --git a/kern/libkern/spinlock.h b/lib/spinlock.h
similarity index 98%
rename from kern/libkern/spinlock.h
rename to lib/spinlock.h
index 9629e60..eb4f4b3 100644
--- a/kern/libkern/spinlock.h
+++ b/lib/spinlock.h
@@ -1,7 +1,7 @@
 #ifndef KERNEL_Spinlock_H
 #define KERNEL_Spinlock_H
 
-#include <stdint.h>
+#include "types.h"
 
 /** Mutual exclusion spin lock */
 struct Spinlock {
diff --git a/lib/string.c b/lib/string.c
new file mode 100644
index 0000000..69fb5c7
--- /dev/null
+++ b/lib/string.c
@@ -0,0 +1,99 @@
+#include <string.h>
+
+char *itoa(int value, char *str, int base) {
+    char        *p = str;
+    char        *p1, *p2;
+    unsigned int uvalue = value;
+    int          negative = 0;
+
+    if (base < 2 || base > 36) {
+        *str = '\0';
+        return str;
+    }
+
+    if (value < 0 && base == 10) {
+        negative = 1;
+        uvalue = -value;
+    }
+
+    // Convert to string
+    do {
+        int digit = uvalue % base;
+        *p++ = (digit < 10) ? '0' + digit : 'a' + (digit - 10);
+        uvalue /= base;
+    } while (uvalue);
+
+    if (negative)
+        *p++ = '-';
+
+    *p = '\0';
+
+    // Reverse string
+    p1 = str;
+    p2 = p - 1;
+    while (p1 < p2) {
+        char tmp = *p1;
+        *p1++ = *p2;
+        *p2-- = tmp;
+    }
+
+    return str;
+}
+
+void *memset(void *dst, int c, size_t length) {
+    u8      *ptr = (u8 *)dst;
+    const u8 value = (u8)c;
+
+    while (length--) *(ptr++) = value;
+
+    return dst;
+}
+
+void *memcpy(void *dst, const void *src, size_t len) {
+    u8       *d = (u8 *)dst;
+    const u8 *s = (const u8 *)src;
+    for (size_t i = 0; i < len; i++) {
+        d[i] = s[i];
+    }
+    return dst;
+}
+
+void *memmove(void *dst, const void *src, size_t len) {
+    u8       *d = (u8 *)dst;
+    const u8 *s = (const u8 *)src;
+    if (d < s) {
+        for (size_t i = 0; i < len; i++) {
+            d[i] = s[i];
+        }
+    } else if (d > s) {
+        for (size_t i = len; i > 0; i--) {
+            d[i - 1] = s[i - 1];
+        }
+    }
+    return dst;
+}
+
+int memcmp(const void *s1, const void *s2, size_t len) {
+    const u8 *a = (const u8 *)s1;
+    const u8 *b = (const u8 *)s2;
+    for (size_t i = 0; i < len; i++) {
+        if (a[i] != b[i]) {
+            return (int)a[i] - (int)b[i];
+        }
+    }
+    return 0;
+}
+
+size_t strlen(const char *s) {
+    const char *p = s;
+    while (*p) ++p;
+    return (size_t)(p - s);
+}
+
+size_t strnlen(const char *s, size_t maxlen) {
+    size_t len = 0;
+    while (len < maxlen && s[len] != '\0') {
+        len++;
+    }
+    return len;
+}
diff --git a/lib/string.h b/lib/string.h
new file mode 100644
index 0000000..00805c7
--- /dev/null
+++ b/lib/string.h
@@ -0,0 +1,40 @@
+#ifndef KERNEL_STRING_H
+#define KERNEL_STRING_H
+
+#include <types.h>
+
+/** Integer to ascii */
+char *itoa(int value, char *str, int base);
+
+/** Fill memory with constant byte */
+void *memset(void *dst, int c, size_t len);
+
+/** Copy `len` bytes from `src` to `dst`. Undefined if regions overlap. */
+void *memcpy(void *dst, const void *src, size_t len);
+
+/** Copy `len` bytes from `src` to `dst`, safe for overlapping regions. */
+void *memmove(void *dst, const void *src, size_t len);
+
+/** Compare `len` bytes of `s1` and `s2`.
+ *  Returns 0 if equal, <0 if s1 < s2, >0 if s1 > s2. */
+int memcmp(const void *s1, const void *s2, size_t len);
+
+/** Returns the length of a null-terminated string */
+size_t strlen(const char *s);
+
+/** Return length of string `s`, up to a max of `maxlen` bytes */
+size_t strnlen(const char *s, size_t maxlen);
+
+// TODO: These:
+/*
+int    strcmp(const char *s1, const char *s2);
+int    strncmp(const char *s1, const char *s2, size_t n);
+
+char  *strcpy(char *dst, const char *src);
+char  *strncpy(char *dst, const char *src, size_t n);
+
+char  *strchr(const char *s, int c);
+char  *strrchr(const char *s, int c);
+*/
+
+#endif
diff --git a/kern/libkern/uart.c b/lib/uart.c
similarity index 100%
rename from kern/libkern/uart.c
rename to lib/uart.c
diff --git a/kern/libkern/uart.h b/lib/uart.h
similarity index 100%
rename from kern/libkern/uart.h
rename to lib/uart.h
diff --git a/kern/libkern/riscv.h b/riscv.h
similarity index 98%
rename from kern/libkern/riscv.h
rename to riscv.h
index ddc19e7..d56bdce 100644
--- a/kern/libkern/riscv.h
+++ b/riscv.h
@@ -1,7 +1,7 @@
 #ifndef RISCV_KERNEL_H
 #define RISCV_KERNEL_H
 
-#include <stdint.h>
+#include <types.h>
 
 /** Page Size */
 #define PGSIZE 4096 // bytes per page
diff --git a/start.c b/start.c
index 10503d1..d0b47c5 100644
--- a/start.c
+++ b/start.c
@@ -4,7 +4,7 @@
 #include <memory.h>
 #include <proc.h>
 #include <riscv.h>
-#include <stdint.h>
+#include <types.h>
 #include <uart.h>
 
 /**
diff --git a/kern/libkern/stdint.h b/types.h
similarity index 94%
rename from kern/libkern/stdint.h
rename to types.h
index 37c912f..69e74d4 100644
--- a/kern/libkern/stdint.h
+++ b/types.h
@@ -13,4 +13,4 @@ typedef uint64_t       size_t;
 
 typedef uint64_t uintptr_t;
 
-// typedef u8 bool;
+typedef u8 bool;