README
1==============================================================================
2Linux Driver Source for Xilinx FPGA firmware download
3==============================================================================
4
5
6TABLE OF CONTENTS.
7
81. SUMMARY
92. BACKGROUND
103. DESIGN
114. HOW TO USE
125. REFERENCE
13
141. SUMMARY
15
16 - Download Xilinx FPGA firmware
17 - This module downloads Xilinx FPGA firmware using gpio pins.
18
192. BACKGROUND
20
21 An FPGA (Field Programmable Gate Array) is a programmable hardware that is
22 used in various applications. Hardware design needs to programmed through
23 a dedicated device or CPU assisted way (serial or parallel).
24 This driver provides a way to download FPGA firmware.
25
263. DESIGN
27
28 - load Xilinx FPGA bitstream format[1] firmware image file using
29 kernel firmware framework, request_firmware()
30 - program the Xilinx FPGA using SelectMAP (parallel) mode [2]
31 - FPGA prgram is done by gpio based bit-banging, as an example
32 - platform independent file: gs_fpgaboot.c
33 - platform dependent file: io.c
34
354. HOW TO USE
36
37 $ insmod gs_fpga.ko file="xlinx_fpga_top_bitstream.bit"
38 $ rmmod gs_fpga
39
405. USE CASE (from a mailing list discussion with Greg)
41
42 a. As a FPGA development support tool,
43 During FPGA firmware development, you need to download a new FPGA
44 image frequently.
45 You would do that with a dedicated JTAG, which usually a limited
46 resource in the lab.
47 However, if you use my driver, you don't have to have a dedicated JTAG.
48 This is a real gain :)
49
50 b. For the FPGA that runs without config after the download, which
51 doesn't talk to any of Linux interfaces (such as PCIE).
52
53 We download FPGA firmware from user triggered or some other way, and that's it.
54 Since that FPGA runs on its own, it doesn't require a linux driver
55 after the download.
56
57 c. For the FPGA that requires config after the download, which talk to
58 any of linux interfaces (such as PCIE)
59
60 Then, this type of FPGA config can be put into device tree and have a
61 separate driver (pcie or others), then THAT driver calls my driver to
62 download FPGA firmware during the Linux boot, the take over the device
63 through the interface.
64
656. REFERENCE
66
67 1. Xilinx APP NOTE XAPP583:
68 https://www.xilinx.com/support/documentation/application_notes/xapp583-fpga-configuration.pdf
69 2. bitstream file info:
70 http://home.earthlink.net/~davesullins/software/bitinfo.html
71