1 files changed, 140 insertions, 0 deletions
diff --git a/arch/powerpc/boot/gunzip_util.c b/arch/powerpc/boot/gunzip_util.c
new file mode 100644
index 00000000000..3d9ff8f081c
--- /dev/null
+++ b/arch/powerpc/boot/gunzip_util.c
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2007 David Gibson, IBM Corporation.
+ * Based on earlier work, Copyright (C) Paul Mackerras 1997.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <stddef.h>
+#include "string.h"
+#include "stdio.h"
+#include "ops.h"
+#include "gunzip_util.h"
+
+struct gunzip_state state;
+
+#define HEAD_CRC	2
+#define EXTRA_FIELD	4
+#define ORIG_NAME	8
+#define COMMENT		0x10
+#define RESERVED	0xe0
+
+void gunzip_start(struct gunzip_state *state, void *src, int srclen)
+{
+	char *hdr = src;
+	int hdrlen = 0;
+
+	memset(state, 0, sizeof(*state));
+
+	/* Check for gzip magic number */
+	if ((hdr[0] == 0x1f) && (hdr[1] == 0x8b)) {
+		/* gzip data, initialize zlib parameters */
+		int r, flags;
+
+		state->s.workspace = state->scratch;
+		if (zlib_inflate_workspacesize() > sizeof(state->scratch)) {
+			printf("insufficient scratch space for gunzip\n\r");
+			exit();
+		}
+
+		/* skip header */
+		hdrlen = 10;
+		flags = hdr[3];
+		if (hdr[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
+			printf("bad gzipped data\n\r");
+			exit();
+		}
+		if ((flags & EXTRA_FIELD) != 0)
+			hdrlen = 12 + hdr[10] + (hdr[11] << 8);
+		if ((flags & ORIG_NAME) != 0)
+			while (hdr[hdrlen++] != 0)
+				;
+		if ((flags & COMMENT) != 0)
+			while (hdr[hdrlen++] != 0)
+				;
+		if ((flags & HEAD_CRC) != 0)
+			hdrlen += 2;
+		if (hdrlen >= srclen) {
+			printf("gunzip_start: ran out of data in header\n\r");
+			exit();
+		}
+
+		r = zlib_inflateInit2(&state->s, -MAX_WBITS);
+		if (r != Z_OK) {
+			printf("inflateInit2 returned %d\n\r", r);
+			exit();
+		}
+	}
+
+	state->s.next_in = src + hdrlen;
+	state->s.avail_in = srclen - hdrlen;
+}
+
+int gunzip_partial(struct gunzip_state *state, void *dst, int dstlen)
+{
+	int len;
+
+	if (state->s.workspace) {
+		/* gunzipping */
+		int r;
+
+		state->s.next_out = dst;
+		state->s.avail_out = dstlen;
+		r = zlib_inflate(&state->s, Z_FULL_FLUSH);
+		if (r != Z_OK && r != Z_STREAM_END) {
+			printf("inflate returned %d msg: %s\n\r", r, state->s.msg);
+			exit();
+		}
+		len = state->s.next_out - (unsigned char *)dst;
+	} else {
+		/* uncompressed image */
+		len = min(state->s.avail_in, (unsigned)dstlen);
+		memcpy(dst, state->s.next_in, len);
+		state->s.next_in += len;
+		state->s.avail_in -= len;
+	}
+	return len;
+}
+
+void gunzip_exactly(struct gunzip_state *state, void *dst, int dstlen)
+{
+	int len;
+
+	len  = gunzip_partial(state, dst, dstlen);
+	if (len < dstlen) {
+		printf("gunzip_block: ran out of data\n\r");
+		exit();
+	}
+}
+
+void gunzip_discard(struct gunzip_state *state, int len)
+{
+	static char discard_buf[128];
+
+	while (len > sizeof(discard_buf)) {
+		gunzip_exactly(state, discard_buf, sizeof(discard_buf));
+		len -= sizeof(discard_buf);
+	}
+
+	if (len > 0)
+		gunzip_exactly(state, discard_buf, len);
+}
+
+int gunzip_finish(struct gunzip_state *state, void *dst, int dstlen)
+{
+	int len;
+
+	if (state->s.workspace) {
+		len = gunzip_partial(state, dst, dstlen);
+		zlib_inflateEnd(&state->s);
+	} else {
+		/* uncompressed image */
+		len = min(state->s.avail_in, (unsigned)dstlen);
+		memcpy(dst, state->s.next_in, len);
+	}
+
+	return len;
+}