1 files changed, 208 insertions, 0 deletions
diff --git a/os/boot/arm1110/inflate.c b/os/boot/arm1110/inflate.c
new file mode 100644
index 00000000..abfed034
--- /dev/null
+++ b/os/boot/arm1110/inflate.c
@@ -0,0 +1,208 @@
+#include "u.h"
+#include "lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include <flate.h>
+
+typedef struct Biobuf	Biobuf;
+
+struct Biobuf
+{
+	uchar *bp;
+	uchar *p;
+	uchar *ep;
+};
+
+static int	header(Biobuf*);
+static int	trailer(Biobuf*, Biobuf*);
+static int	getc(void*);
+static ulong	offset(Biobuf*);
+static int	crcwrite(void *out, void *buf, int n);
+static ulong	get4(Biobuf *b);
+static ulong	Boffset(Biobuf *bp);
+
+/* GZIP flags */
+enum {
+	Ftext=		(1<<0),
+	Fhcrc=		(1<<1),
+	Fextra=		(1<<2),
+	Fname=		(1<<3),
+	Fcomment=	(1<<4),
+
+	GZCRCPOLY	= 0xedb88320UL,
+};
+
+static ulong	*crctab;
+static ulong	crc;
+
+int
+gunzip(uchar *out, int outn, uchar *in, int inn)
+{
+	Biobuf bin, bout;
+	int err;
+
+	crc = 0;
+	crctab = mkcrctab(GZCRCPOLY);
+	err = inflateinit();
+	if(err != FlateOk)
+		print("inflateinit failed: %s\n", flateerr(err));
+
+	bin.bp = bin.p = in;
+	bin.ep = in+inn;
+	bout.bp = bout.p = out;
+	bout.ep = out+outn;
+
+	err = header(&bin);
+	if(err != FlateOk)
+		return err;
+
+	err = inflate(&bout, crcwrite, &bin, getc);
+	if(err != FlateOk)
+		print("inflate failed: %s\n", flateerr(err));
+
+	err = trailer(&bout, &bin);
+	if(err != FlateOk)
+		return err;
+
+	return Boffset(&bout);
+}
+
+static int
+header(Biobuf *bin)
+{
+	int i, flag;
+
+	if(getc(bin) != 0x1f || getc(bin) != 0x8b){
+		print("bad magic\n");
+		return FlateCorrupted;
+	}
+	if(getc(bin) != 8){
+		print("unknown compression type\n");
+		return FlateCorrupted;
+	}
+	
+	flag = getc(bin);
+	
+	/* mod time */
+	get4(bin);
+	
+	/* extra flags */
+	getc(bin);
+	
+	/* OS type */
+	getc(bin);
+
+	if(flag & Fextra)
+		for(i=getc(bin); i>0; i--)
+			getc(bin);
+	
+	/* name */
+	if(flag&Fname)
+		while(getc(bin) != 0)
+			;
+
+	/* comment */
+	if(flag&Fcomment)
+		while(getc(bin) != 0)
+			;
+
+	/* crc16 */
+	if(flag&Fhcrc) {
+		getc(bin);
+		getc(bin);
+	}
+		
+	return FlateOk;
+}
+
+static int
+trailer(Biobuf *bout, Biobuf *bin)
+{
+	/* crc32 */
+	ulong x;
+
+	x = get4(bin);
+	if(crc != x){
+		print("crc mismatch %lux %lux\n", crc, x);
+		return FlateCorrupted;
+	}
+
+	/* length */
+	if(get4(bin) != Boffset(bout)){
+		print("bad output len\n");
+		return FlateCorrupted;
+	}
+	return FlateOk;
+}
+
+static ulong
+get4(Biobuf *b)
+{
+	ulong v;
+	int i, c;
+
+	v = 0;
+	for(i = 0; i < 4; i++){
+		c = getc(b);
+		v |= c << (i * 8);
+	}
+	return v;
+}
+
+static int
+getc(void *in)
+{
+	Biobuf *bp = in;
+
+	if((bp->p - bp->bp) % 10000 == 0)
+		print(".");
+	if(bp->p >= bp->ep)
+		return -1;
+	return *bp->p++;
+}
+
+static ulong
+Boffset(Biobuf *bp)
+{
+	return bp->p - bp->bp;
+}
+
+static int
+crcwrite(void *out, void *buf, int n)
+{
+	Biobuf *bp;
+
+	crc = blockcrc(crctab, crc, buf, n);
+	bp = out;
+	if(n > bp->ep-bp->p)
+		n = bp->ep-bp->p;
+	memmove(bp->p, buf, n);
+	bp->p += n;
+	return n;
+}
+
+#undef malloc
+#undef free
+
+static ulong ibrkp = ~0;
+
+void *
+malloc(ulong n)
+{
+	ulong rv;
+
+	if(ibrkp == ~0)
+		ibrkp = ((ulong)end)+1024*1024;
+	n = (n+3)>>2;
+	n <<= 2;
+	rv = ibrkp;
+	ibrkp += n;
+	return (void*)rv;
+}
+
+void
+free(void *)
+{
+}