+
+//----------------------------------------------------------------------------
+// Uncompress (inflate) the FPGA data. Returns one decompressed byte with
+// each call.
+//----------------------------------------------------------------------------
+static int get_from_fpga_combined_stream(z_streamp compressed_fpga_stream, uint8_t *output_buffer)
+{
+ if (fpga_image_ptr == compressed_fpga_stream->next_out) { // need more data
+ compressed_fpga_stream->next_out = output_buffer;
+ compressed_fpga_stream->avail_out = OUTPUT_BUFFER_LEN;
+ fpga_image_ptr = output_buffer;
+ int res = inflate(compressed_fpga_stream, Z_SYNC_FLUSH);
+
+ if (res != Z_OK)
+ Dbprintf("inflate returned: %d, %s", res, compressed_fpga_stream->msg);
+
+ if (res < 0)
+ return res;
+ }
+
+ ++uncompressed_bytes_cnt;
+
+ return *fpga_image_ptr++;
+}
+
+//----------------------------------------------------------------------------
+// Undo the interleaving of several FPGA config files. FPGA config files
+// are combined into one big file:
+// 288 bytes from FPGA file 1, followed by 288 bytes from FGPA file 2, etc.
+//----------------------------------------------------------------------------
+static int get_from_fpga_stream(int bitstream_version, z_streamp compressed_fpga_stream, uint8_t *output_buffer)
+{
+ while((uncompressed_bytes_cnt / FPGA_INTERLEAVE_SIZE) % FPGA_BITSTREAM_MAX != (bitstream_version - 1)) {
+ // skip undesired data belonging to other bitstream_versions
+ get_from_fpga_combined_stream(compressed_fpga_stream, output_buffer);
+ }
+
+ return get_from_fpga_combined_stream(compressed_fpga_stream, output_buffer);
+}
+
+
+static voidpf fpga_inflate_malloc(voidpf opaque, uInt items, uInt size)
+{
+ return BigBuf_malloc(items*size);
+}
+
+
+static void fpga_inflate_free(voidpf opaque, voidpf address)
+{
+ BigBuf_free();
+}
+
+
+//----------------------------------------------------------------------------
+// Initialize decompression of the respective (HF or LF) FPGA stream
+//----------------------------------------------------------------------------
+static bool reset_fpga_stream(int bitstream_version, z_streamp compressed_fpga_stream, uint8_t *output_buffer)
+{
+ uint8_t header[FPGA_BITSTREAM_FIXED_HEADER_SIZE];
+
+ uncompressed_bytes_cnt = 0;
+
+ // initialize z_stream structure for inflate:
+ compressed_fpga_stream->next_in = &_binary_obj_fpga_all_bit_z_start;
+ compressed_fpga_stream->avail_in = &_binary_obj_fpga_all_bit_z_start - &_binary_obj_fpga_all_bit_z_end;
+ compressed_fpga_stream->next_out = output_buffer;
+ compressed_fpga_stream->avail_out = OUTPUT_BUFFER_LEN;
+ compressed_fpga_stream->zalloc = &fpga_inflate_malloc;
+ compressed_fpga_stream->zfree = &fpga_inflate_free;
+
+ inflateInit2(compressed_fpga_stream, 0);
+
+ fpga_image_ptr = output_buffer;
+
+ for (uint16_t i = 0; i < FPGA_BITSTREAM_FIXED_HEADER_SIZE; i++)
+ header[i] = get_from_fpga_stream(bitstream_version, compressed_fpga_stream, output_buffer);
+
+ // Check for a valid .bit file (starts with _bitparse_fixed_header)
+ if(memcmp(_bitparse_fixed_header, header, FPGA_BITSTREAM_FIXED_HEADER_SIZE) == 0)
+ return true;
+
+ return false;
+}
+
+