FPGA loader

On this page, you will find all the informations needed to use the Linux FPGA loader driver. This driver allows you to load the FPGA of your APF board from Linux userspace/shell (ie FPGA reprogrammation after Linux boot).

Driver installation

Driver is installed in default Armadeus rootfs.

For the hackers, code is located in target/linux/modules/fpga/dev_tools/fpga_devtools/.

Driver usage

 # modprobe fpgaloader
 fpgaloader v0.9

• The FPGA loader driver is usable through the standard Linux filesystem interface. To read the available configuration, do:

 # cat /proc/driver/fpga/loader
 spartan slave serial

• To upload a new firmware (here bramtest_top_apf.bin), use:

 # dd if=bramtest_top_apf.bin of=/dev/fpgaloader

• Since 3.1 release, there is a small helper script that can do all the job for you (load driver and then firmware). Just call it with the bitfile as parameter. For example:

 # load_fpga bramtest_top_apf.bin

• You can find some ready to use bitfiles in firmware/leds/blinking_led/bin/ (blinking LED).

Troubleshots

• If the dd is executed just after the modprobe an error may occur (no space left on device). This can be avoid with this small script:

 modprobe fpgaloader
 while [ ! -c /dev/fpgaloader ]; do
     usleep 1000
 done
 dd if=bramtest_top_apf.bin of=/dev/fpgaloader

This is one of the things that is done by the /usr/bin/load_fpga utility, mentionned above.