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-rw-r--r--arch/xtensa/boot/lib/zmem.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/xtensa/boot/lib/zmem.c b/arch/xtensa/boot/lib/zmem.c
new file mode 100644
index 000000000..b89189355
--- /dev/null
+++ b/arch/xtensa/boot/lib/zmem.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/zlib.h>
+
+/* bits taken from ppc */
+
+extern void *avail_ram, *end_avail;
+void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp);
+
+static void exit(void)
+{
+ for (;;);
+}
+
+static void *zalloc(unsigned int size)
+{
+ void *p = avail_ram;
+
+ size = (size + 7) & -8;
+ avail_ram += size;
+ if (avail_ram > end_avail) {
+ //puts("oops... out of memory\n");
+ //pause();
+ exit ();
+ }
+ return p;
+}
+
+#define HEAD_CRC 2
+#define EXTRA_FIELD 4
+#define ORIG_NAME 8
+#define COMMENT 0x10
+#define RESERVED 0xe0
+
+#define DEFLATED 8
+
+void gunzip (void *dst, int dstlen, unsigned char *src, int *lenp)
+{
+ z_stream s;
+ int r, i, flags;
+
+ /* skip header */
+ i = 10;
+ flags = src[3];
+ if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
+ //puts("bad gzipped data\n");
+ exit();
+ }
+ if ((flags & EXTRA_FIELD) != 0)
+ i = 12 + src[10] + (src[11] << 8);
+ if ((flags & ORIG_NAME) != 0)
+ while (src[i++] != 0)
+ ;
+ if ((flags & COMMENT) != 0)
+ while (src[i++] != 0)
+ ;
+ if ((flags & HEAD_CRC) != 0)
+ i += 2;
+ if (i >= *lenp) {
+ //puts("gunzip: ran out of data in header\n");
+ exit();
+ }
+
+ s.workspace = zalloc(zlib_inflate_workspacesize());
+ r = zlib_inflateInit2(&s, -MAX_WBITS);
+ if (r != Z_OK) {
+ //puts("inflateInit2 returned "); puthex(r); puts("\n");
+ exit();
+ }
+ s.next_in = src + i;
+ s.avail_in = *lenp - i;
+ s.next_out = dst;
+ s.avail_out = dstlen;
+ r = zlib_inflate(&s, Z_FINISH);
+ if (r != Z_OK && r != Z_STREAM_END) {
+ //puts("inflate returned "); puthex(r); puts("\n");
+ exit();
+ }
+ *lenp = s.next_out - (unsigned char *) dst;
+ zlib_inflateEnd(&s);
+}
+