On 5/17/22 15:41, adrian.ho.yin.ng@xxxxxxxxx wrote: > 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 > + Missing (c). > +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. Use .rst for writing docs in Documentation/ (and fix any warnings found). -- An old man doll... just what I always wanted! - Clara
