Xilinx Bitstream Format Library

This library lets you open and read the header of the Xilinx .bit format. It has no knowledge of anything inside of the bit-stream. It only knows what the header is and what it means, how long is the data section and how many bytes there are. But it can print .bit information, such as synthesis date, source .ncd file name and others.

How to build

In order to build the library run:

make

You can also run the regression test suite:

make fetch

It'll fetch several .bit files from the official NetFPGA repository (be warned -- it's 82MB by the time of writing this document). And then:

make test

Which will verify that your changes didn't bring backward compatibility problems. The check shows a differences between the output files after your changes and 'golden model' references.

API explanation

API calls are pretty self-explanatory and are mentioned below.

void xbf_init(struct xbf *xbf)

• Initialize the xbf structure for further operation.

int xbf_open(struct xbf *xbf, const char *fname)

• Open the file under fname and initialize the xbf context with it.

int xbf_open_mem(struct xbf *xbf, void *mem, size_t mem_size)

• Just like xbf_open(), but take the data of size mem_size from mem pointer.

int xbf_opened(struct xbf *xbf)

• Return true/false if the xbf pointer has been opened correctly.

int xbf_close(struct xbf *xbf)

• Close the context related with xbf

const char *xbf_errmsg(struct xbf *xbf)

• In case of error, this function will return a user-facing error message.

const char *xbf_get_time(struct xbf *xbf),

const char *xbf_get_date(struct xbf *xbf),

const char *xbf_get_partname(struct xbf *xbf),

const char *xbf_get_ncdname(struct xbf *xbf),

const char *xbf_get_fname(struct xbf *xbf)

• All these functions return time, data, part name, .ncd file name and file name respectively. Passed xbf must have been opened correctly.

size_t xbf_get_len(struct xbf *xbf), const unsigned char *xbf_get_data(struct xbf *xbf)

• Print the length of data under opened xbf and return its data, respectively.

void xbf_print_fp(FILE *fp, struct xbf *xbf),

void xbf_print(struct xbf *xbf)

• Print debugging data to file pointer fp. The xbf_print is equivalent to xbf_print_fp(stdout, xbf)

Examples

Take a look at makefile. It shows how to use xbf (the test program). The Travis badge will show you this use-case in action:

For API example, look into xbf.c, function bf_test. The main of xbf.c has a real-world code snippet. You can steal it to start from.

Author

• Wojciech Adam Koszek, [email protected]
• http://www.koszek.com