initial commit of lk (little kernel) project
diff --git a/include/endian.h b/include/endian.h
new file mode 100644
index 0000000..30623b2
--- /dev/null
+++ b/include/endian.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2008 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef __ENDIAN_H
+#define __ENDIAN_H
+
+#include <sys/types.h>
+
+#ifndef LITTLE_ENDIAN
+#define LITTLE_ENDIAN 1234
+#endif
+#ifndef BIG_ENDIAN
+#define BIG_ENDIAN 4321
+#endif
+
+#if __POWERPC__
+#include <ppc_intrinsics.h>
+#endif
+
+#if defined(ARCH_ARM)
+#define BYTE_ORDER LITTLE_ENDIAN
+#endif
+
+#ifndef BYTE_ORDER
+#error "need to get the BYTE_ORDER define from somewhere"
+#endif
+
+// define a macro that unconditionally swaps
+#define SWAP_32(x) \
+ (((uint32_t)(x) << 24) | (((uint32_t)(x) & 0xff00) << 8) |(((uint32_t)(x) & 0x00ff0000) >> 8) | ((uint32_t)(x) >> 24))
+#define SWAP_16(x) \
+ ((((uint16_t)(x) & 0xff) << 8) | ((uint16_t)(x) >> 8))
+
+// standard swap macros
+#if BYTE_ORDER == BIG_ENDIAN
+#define LE32(val) SWAP_32(val)
+#define LE16(val) SWAP_16(val)
+#define BE32(val) (val)
+#define BE16(val) (val)
+#else
+#define LE32(val) (val)
+#define LE16(val) (val)
+#define BE32(val) SWAP_32(val)
+#define BE16(val) SWAP_16(val)
+#endif
+
+#define LE32SWAP(var) (var) = LE32(var);
+#define LE16SWAP(var) (var) = LE16(var);
+#define BE32SWAP(var) (var) = BE32(var);
+#define BE16SWAP(var) (var) = BE16(var);
+
+/* classic network byte swap stuff */
+#define ntohs(n) BE16(n)
+#define htons(h) BE16(h)
+#define ntohl(n) BE32(n)
+#define htonl(h) BE32(h)
+
+// some memory access macros
+#if __POWERPC__
+#define READ_MEM_WORD(ptr) __lwbrx((word *)(ptr), 0)
+#define READ_MEM_HALFWORD(ptr) __lhbrx((halfword *)(ptr), 0)
+#define READ_MEM_BYTE(ptr) (*(byte *)(ptr))
+#define WRITE_MEM_WORD(ptr, data) __stwbrx(data, (word *)(ptr), 0)
+#define WRITE_MEM_HALFWORD(ptr, data) __sthbrx(data, (halfword *)(ptr), 0)
+#define WRITE_MEM_BYTE(ptr, data) (*(byte *)(ptr) = (data))
+#else
+#define READ_MEM_WORD(ptr) SWAPIT_32(*(word *)(ptr))
+#define READ_MEM_HALFWORD(ptr) SWAPIT_16(*(halfword *)(ptr))
+#define READ_MEM_BYTE(ptr) (*(byte *)(ptr))
+#define WRITE_MEM_WORD(ptr, data) (*(word *)(ptr) = SWAPIT_32(data))
+#define WRITE_MEM_HALFWORD(ptr, data) (*(halfword *)(ptr) = SWAPIT_16(data))
+#define WRITE_MEM_BYTE(ptr, data) (*(byte *)(ptr) = (data))
+#endif
+
+
+#endif