the unknown element of the data_in struct is the current working byte

[rsbs2] / rsb-lz.c

diff --git a/rsb-lz.c b/rsb-lz.c
index b45f0f8dc27939c160d958c188afd39e597b4580..5f290d8fdad2bc4e71adc8dccdfb007d934398a7 100644 (file)
--- a/rsb-lz.c
+++ b/rsb-lz.c
@@ -17,8 +17,8 @@ void err_exit(const char *fname)
 struct data_in_s {
        unsigned char *start; /* 0 */
        unsigned char *stop; /* 4 */
-       unsigned char bit; /* 8 */
-       unsigned char x; /* 9 */
+       unsigned char bitpos; /* 8 */
+       unsigned char byte; /* 9 */
 };
 
 struct data_out_s {
@@ -26,48 +26,32 @@ struct data_out_s {
        unsigned char *end;
 };
 
-unsigned char fn_597c8(struct data_in_s *r6_data)
+unsigned char get_next_in_byte(struct data_in_s *data_in)
 {
-       unsigned char *r0;
-       unsigned char *r1;
-       unsigned char r5;
-
-       r5 = 0;
+       unsigned char byte;
 
-       r0 = r6_data->start;
-       r1 = r6_data->stop;
-
-       if (r1 < r0)
+       if (data_in->stop < data_in->start)
                err_exit(__func__);
 
-       r5 = *r0;
-       r0++;
-       r6_data->start = r0;
+       byte = *(data_in->start);
+       data_in->start++;
 
-       return r5;
+       return byte;
 }
 
-unsigned int fn_59848(struct data_in_s *r6_data)
+unsigned char fn_59848(struct data_in_s *data_in)
 {
-       unsigned char r1;
-       unsigned char r2;
-       unsigned int r5;
+       unsigned char r5;
 
-       r1 = r6_data->bit;
-       if (r1 == 0x80) {
-               r6_data->x = fn_597c8(r6_data);
+       if (data_in->bitpos == 0x80) {
+               data_in->byte = get_next_in_byte(data_in);
        }
-       r1 = r6_data->bit;
-       r2 = r6_data->x;
-       r1 = r1 & r2;
-       r5 = r1 & 0xff;
-
-       r1 = r6_data->bit;
-       r1 = r1 >> 1;
-       r6_data->bit = r1;
-       if (r1 == 0) {
-               r1 = 0x80;
-               r6_data->bit = r1;
+
+       r5 = data_in->bitpos & data_in->byte;
+
+       data_in->bitpos >>= 1;
+       if (data_in->bitpos == 0) {
+               data_in->bitpos = 0x80;
        }
 
        if (r5 == 0)
@@ -78,59 +62,39 @@ unsigned int fn_59848(struct data_in_s *r6_data)
 
 unsigned int fn_598b4(struct data_in_s *r11_data, unsigned int r10_arg2)
 {
-       unsigned int r1;
-       unsigned int r2;
        unsigned int r6;
        unsigned int r7;
 
-       r1 = r10_arg2 - 1;
-       r6 = 1 << r1;
+       r6 = 1 << (r10_arg2 - 1);
 
        r7 = 0;
        while (r6 != 0) {
-               r1 = r11_data->bit;
-               if (r1 == 0x80) {
-                       r1 = fn_597c8(r11_data);
-                       r11_data->x = r1;
+               if (r11_data->bitpos == 0x80) {
+                       r11_data->byte = get_next_in_byte(r11_data);
                }
-               r1 = r11_data->bit;
-               r2 = r11_data->x;
-               r1 = r1 & r2;
-               if (r1 != 0)
+               if ((r11_data->bitpos & r11_data->byte) != 0)
                        r7 = r7 | r6;
 
                r6 = r6 >> 1;
 
-               r2 = r11_data->bit;
-               r2 = r2 >> 1;
-               r11_data->bit = r2;
+               r11_data->bitpos >>= 1;
 
-               r1 = r11_data->bit;
-               if(r1 == 0) {
-                       r11_data->bit = 0x80;
+               if(r11_data->bitpos == 0) {
+                       r11_data->bitpos = 0x80;
                }
        }
 
        return r7;
 }
 
-void fn_5980c(unsigned int arg1, struct data_out_s *data_out)
+void write_byte(unsigned char byte, struct data_out_s *data_out)
 {
-       unsigned char *r1;
-       unsigned char *r2;
-
-       r1 = data_out->pos;
-       r2 = data_out->end;
-
-       if (r1 > r2) {
-               printf("r1: 0x%08x, r2: 0x%08x\n", (unsigned int)r1, (unsigned int)r2);
+       if (data_out->pos > data_out->end) {
                err_exit(__func__);
        }
 
-       *r1 = arg1 & 0xff;
-
-       r1++;
-       data_out->pos = r1;
+       *(data_out->pos) = byte;
+       data_out->pos++;
 }
 
 void lz_expand(struct data_in_s *r10_data, struct data_out_s *data_out)
@@ -141,7 +105,7 @@ void lz_expand(struct data_in_s *r10_data, struct data_out_s *data_out)
        unsigned int r6;
        unsigned int r7;
        unsigned int r11;
-       unsigned char arr_59b64[2048];
+       unsigned char arr_59b64[1024];
 
        r5 = 1;
 
@@ -152,14 +116,10 @@ void lz_expand(struct data_in_s *r10_data, struct data_out_s *data_out)
                                break;
 
                        r2 = fn_598b4(r10_data, 8) & 0xff;
-                       r4 = r2;
-
-                       fn_5980c(r4, data_out);
-                       arr_59b64[r5] = r4 & 0xff;
-                       r2 = r5 + 1;
-                       r2 = r2 << 22;
-                       r2 = r2 >> 22;
-                       r5 = r2;
+
+                       write_byte(r2, data_out);
+                       arr_59b64[r5] = r2 & 0xff;
+                       r5 = (r5 + 1) & 0x3ff;
                }
 
                r11 = fn_598b4(r10_data, 0x0a);
@@ -170,21 +130,18 @@ void lz_expand(struct data_in_s *r10_data, struct data_out_s *data_out)
                r7 = r2 + 1;
                r6 = 0;
                while (r6 <= r7) {
-                       r2 = r6 + r11;
-                       r2 = r2 << 22;
-                       r2 = r2 >> 22;
+                       r2 = (r6 + r11) & 0x3ff;
                        r4 = arr_59b64[r2];
-                       fn_5980c(r4, data_out);
+                       write_byte(r4, data_out);
                        arr_59b64[r5] = r4;
-                       r2 = r5 + 1;
-                       r2 = r2 << 22;
-                       r2 = r2 >> 22;
-                       r5 = r2;
+                       r5 = (r5 + 1) & 0x3ff;
                        r6++;
                }
        }
 }
 
+/* Checksum is only used for the compressed firmware in 'firmware' */
+#if 0
 unsigned int crc_check_59684(unsigned char *arg1, unsigned int arg2, unsigned int magic)
 {
        unsigned int r3;
@@ -218,6 +175,7 @@ unsigned int crc_check_59684(unsigned char *arg1, unsigned int arg2, unsigned in
 
        return 4;
 }
+#endif
 
 void extract_lz_file(unsigned char *inbuf, unsigned char *name)
 {
@@ -241,8 +199,8 @@ void extract_lz_file(unsigned char *inbuf, unsigned char *name)
 
        data_in.start = inbuf + 8;
        data_in.stop = inbuf + len;
-       data_in.x = 0;
-       data_in.bit = 0x80;
+       data_in.byte = 0x00;
+       data_in.bitpos = 0x80;
 
        data_out.pos = outbuf;
        data_out.end = outbuf + len;
@@ -250,7 +208,7 @@ void extract_lz_file(unsigned char *inbuf, unsigned char *name)
        lz_expand(&data_in, &data_out);
 
 #if 0
-       /* This seems to still be completely broken */
+       /* Checksum is only used for the compressed firmware in 'firmware' */
        r3 = r7 + 0x20;
        r5 = *((unsigned int*)r3);