Reworked the code that is inteded to be usable for kernel

and initramfs decompression.

Linux 2.6.30 will have bzip2 and lzma support. This commit
adds a wrapper to convert the native XZ decompressor API to
the decompressor API that is used for kernel and initramfs
decompression in 2.6.30.

2 files changed, 3 insertions, 227 deletions

diff --git a/linux/lib/xz/xz_boot.c b/linux/lib/xz/xz_boot.c
deleted file mode 100644
index 685fc4b..0000000
--- a/linux/lib/xz/xz_boot.c
+++ /dev/null
@@ -1,226 +0,0 @@
-/*
- * XZ decoder as a single file for uncompressing the kernel and initramfs
- *
- * Author: Lasse Collin <lasse.collin@tukaani.org>
- *
- * This file has been put into the public domain.
- * You can do whatever you want with this file.
- */
-
-/*
- * Before #including this file, void error(char *) or void error(const char *)
- * must have been declared. It is called from xz_dec_buf() if an error
- * occurs; if error() returns, xz_dec_buf() will return false. On success,
- * xz_dec_buf() returns true, but if error() would never return, there's no
- * need to check the return value of xz_dec_buf().
- *
- * In the early phase of boot where kmalloc, memmove, and friends are not
- * available, you need to #define XZ_MEM_FUNCS before #including this file.
- * Before calling xz_dec_buf, set malloc_buf to the beginning of a workspace
- * buffer, and malloc_avail to the size of the workspace buffer. malloc_buf
- * must be aligned to a multiple of 8 bytes. About 30 KiB of space is
- * currently needed, but to be future-proof, having 40-50 KiB of space would
- * be good.
- *
- * Example:
- *
- *      static void error(const char *message);
- *      #define XZ_MEM_FUNCS
- *      #include "../../../../lib/xz/xz_boot.c"
- *      ...
- *      struct xz_buf b;
- *      b.in = (const uint8_t *)in_buf;
- *      b.in_pos = 0;
- *      b.in_size = in_buf_size;
- *      b.out = (uint8_t *)out_buf;
- *      b.out_pos = 0;
- *      b.out_size = out_buf_size_max;
- *      malloc_buf = (uint8_t *)free_mem_begin;
- *      malloc_avail = free_mem_avail;
- *      if (!xz_dec_buf(&b))
- *              goto error_handler;
- *
- * If xz_dec_buf() succeeded (it returned true), the amount if input consumed
- * is in b.in_pos and the amount of output used is in b.out_pos.
- */
-
-/*
- * Allow using the macro INIT to mark all functions with __init.
- * INIT is already used for this purporse in the Deflate decoder,
- * so this should ease things a little.
- */
-#if !defined(XZ_FUNC) && defined(INIT)
-#	define XZ_FUNC INIT
-#endif
-
-/*
- * Use the internal CRC32 code instead of kernel's CRC32 module, which
- * is not available in early phase of booting.
- */
-#define XZ_INTERNAL_CRC32
-
-/*
- * Ignore the configuration specified in the kernel config for the xz_dec
- * module. For boot time use, we enable only the BCJ filter of the current
- * architecture, or none if no BCJ filter is available for the architecture.
- */
-#define XZ_IGNORE_KCONFIG
-#ifdef CONFIG_X86
-#	define XZ_DEC_X86
-#endif
-#ifdef CONFIG_PPC
-#	define XZ_DEC_POWERPC
-#endif
-#ifdef CONFIG_ARM
-#	define XZ_DEC_ARM
-#endif
-#ifdef CONFIG_IA64
-#	define XZ_DEC_IA64
-#endif
-#ifdef CONFIG_SPARC
-#	define XZ_DEC_SPARC
-#endif
-
-#include "xz_private.h"
-
-#ifdef XZ_MEM_FUNCS
-/* Replace the normal allocation functions with our simple version. */
-#undef kmalloc
-#undef kfree
-#undef vmalloc
-#undef vfree
-#define kmalloc(size, flags) malloc(size)
-#define kfree(ptr) ((void)0)
-#define vmalloc(size) malloc(size)
-#define vfree(ptr) ((void)0)
-
-/*
- * Very simple malloc, which just picks big enough chunk from a preallocated
- * buffer. There's no free(), because the decoder is (at least for now) used
- * only once per compilation unit. Thus, free() would be just waste of space.
- */
-static uint8_t *malloc_buf;
-static size_t malloc_avail;
-
-static void * XZ_FUNC malloc(size_t size)
-{
-	void *ptr = malloc_buf;
-	size = (size + 7) & ~(size_t)7;
-	if (size > malloc_avail)
-		return NULL;
-
-	malloc_buf += size;
-	malloc_avail -= size;
-	return ptr;
-}
-
-/*
- * memeq and memzero are not used much and any remotely sane implementation
- * is fast enough. memcpy/memmove speed matters in multi-call mode, but
- * xz_dec_buf() uses only the single-call mode, in which only memcpy speed
- * can matter and only if there is a lot of uncompressible data (LZMA2 stores
- * uncompressible chunks in uncompressed form). Thus, the functions below
- * should just be kept small; it's probably not worth optimizing for speed.
- */
-static bool XZ_FUNC memeq(const void *a, const void *b, size_t size)
-{
-	const uint8_t *x = a;
-	const uint8_t *y = b;
-	size_t i;
-
-	for (i = 0; i < size; ++i)
-		if (x[i] != y[i])
-			return false;
-
-	return true;
-}
-
-static void XZ_FUNC memzero(void *buf, size_t size)
-{
-	uint8_t *b = buf;
-	uint8_t *e = b + size;
-	while (b != e)
-		*b++ = '\0';
-}
-
-static void * XZ_FUNC memmove(void *dest, const void *src, size_t size)
-{
-	uint8_t *d = dest;
-	const uint8_t *s = src;
-	size_t i;
-
-	if (d < s) {
-		for (i = 0; i < size; ++i)
-			d[i] = s[i];
-	} else if (d > s) {
-		i = size;
-		while (i-- > 0)
-			d[i] = s[i];
-	}
-
-	return dest;
-}
-
-/* Since we need memmove anyway, use it as memcpy too. */
-#define memcpy memmove
-#endif
-
-#include "xz_crc32.c"
-#include "xz_dec_stream.c"
-#include "xz_dec_lzma2.c"
-#ifdef XZ_DEC_BCJ
-#	include "xz_dec_bcj.c"
-#endif
-
-/**
- * xz_dec_buf() - Single-call XZ decoder
- * @b:          Input and output buffers
- *
- * On success, true is returned. On error, error() is called and false is
- * returned in case error() returns.
- */
-static bool XZ_FUNC xz_dec_buf(struct xz_buf *b)
-{
-	struct xz_dec *s;
-	enum xz_ret ret;
-
-	xz_crc32_init();
-
-	s = xz_dec_init(0);
-	if (s == NULL) {
-		error("XZ decoder ran out of memory");
-		return false;
-	}
-
-	ret = xz_dec_run(s, b);
-	xz_dec_end(s);
-
-	switch (ret) {
-	case XZ_STREAM_END:
-		return true;
-
-	case XZ_FORMAT_ERROR:
-		error("Input is not in the XZ format (wrong magic bytes)");
-		break;
-
-	case XZ_OPTIONS_ERROR:
-		error("Input was encoded with settings that are not "
-				"supported by this XZ decoder");
-		break;
-
-	case XZ_DATA_ERROR:
-		error("XZ-compressed data is corrupt");
-		break;
-
-	case XZ_BUF_ERROR:
-		error("Output buffer is too small or the "
-				"XZ-compressed data is corrupt");
-		break;
-
-	default:
-		error("Bug in the XZ decoder");
-		break;
-	}
-
-	return false;
-}
diff --git a/linux/lib/xz/xz_private.h b/linux/lib/xz/xz_private.h
index 866954b..f5f4bf4 100644
--- a/linux/lib/xz/xz_private.h
+++ b/linux/lib/xz/xz_private.h
@@ -11,7 +11,8 @@
 #define XZ_PRIVATE_H
 
 #ifdef __KERNEL__
-#	ifndef XZ_MEM_FUNCS
+	/* XZ_STATIC may be defined only via decompress_unxz.c. */
+#	ifndef XZ_STATIC
 #		include <linux/slab.h>
 #		include <linux/vmalloc.h>
 #		include <linux/string.h>
@@ -21,6 +22,7 @@
 #	include <asm/byteorder.h>
 #	include <asm/unaligned.h>
 #	define get_le32(p) le32_to_cpup((const uint32_t *)(p))
+	/* XZ_IGNORE_KCONFIG may be defined only via decompress_unxz.c. */
 #	ifndef XZ_IGNORE_KCONFIG
 #		ifdef CONFIG_XZ_DEC_X86
 #			define XZ_DEC_X86