From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> Document the DebugFS interface for the core FPGA Manager framework. Signed-off-by: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> --- Documentation/fpga/debugfs.txt | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/fpga/debugfs.txt diff --git a/Documentation/fpga/debugfs.txt b/Documentation/fpga/debugfs.txt new file mode 100644 index 000000000000..1b34d5460d5d --- /dev/null +++ b/Documentation/fpga/debugfs.txt @@ -0,0 +1,33 @@ +FPGA Manager DebugFS interface for FPGA reprogramming. + +Alan Tull 2016 + +Each FPGA gets its own directory such as <debugfs>/fpga_manager/fpga0 and +three files: + + - [RW] flags: flags as defined in fpga-mgr.h. For example: + + $ echo 1 > /sys/kernel/debug/fpga_manager/fpga0/flags + + - [RW] firmware_name: Name of an FPGA image firmware file. Writing initiates + a complete FPGA programming cycle. Note that the image + file must be in a directory on the firmware search path + such as /lib/firmware. + + $ echo image.rbf > /sys/kernel/debug/fpga_manager/fpga0/firmware_name + + - [WO] image: Raw FPGA image data. Writing the FPGA image data will + initiate a complete FPGA programming cycle. Data must + be written in one chunk, for example: + + $ dd bs=10M if=./image.rbf of=/sys/kernel/debug/fpga_manager/fpga0/image + (where image.rbf < 10M) + +To program the FPGA, write the flags (if needed), then use either the +firmware_name or image file to program. + +This interface does not handle bridges or loading/unloading of soft IP device +drivers. This makes it really easy to mess things up by doing things like +reprogramming the hardware out from under a driver or reprogramming while a +bridge is enabled, causing gunk to go out on a cpu bus. It should go without +saying that this interface is for debug only. Not intended for production use. -- 2.26.2
