Module: Xilinx::Provision::CableFirmware

Defined in:
lib/xilinx/provision/cable_firmware.rb

Overview

Finds firmware files for the Xilinx USB cable and sets up automatic uploading.

The USB cables are weird beasts. A cable contains a small FPGA that must be programmed every time the cable is powered up, which happens on every connection to the computer.

Xilinx ISE ships with the firmware for all cable types, but it doesn’t automatically upload the firmware when needed. Udev to the rescue!

Class Method Summary collapse

Class Method Details

.configure_udev ⇒ Object

Sets up the udev daemon to allow non-root access to the USB cable.



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# File 'lib/xilinx/provision/cable_firmware.rb', line 30

def self.configure_udev
  Xilinx::Provision::Udev.add_rules udev_rules,
                                    '71-xilinx-usb-firmware-upload'
  nil
end

.rules_path ⇒ Object

The path to the firmware upload rules file that ships with ISE.

This file is written in old-style udev, so it needs to be converted.

Returns a path to the rules file, or nil if the file cannot be found.



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# File 'lib/xilinx/provision/cable_firmware.rb', line 70

def self.rules_path
  dir_path = Xilinx::Provision::Impact.path
  until dir_path == '/' || dir_path.empty?
    dir_path = File.dirname dir_path
    matches = Dir[File.join(dir_path, '**', '*.rules')]
    next if matches.empty?
    if matches.length > 1
      better_matches = Dir[File.join(dir_path, '**', 'xusbdfwu.rules')]
      matches = better_matches unless better_matches.empty?
    end
    return matches.sort.last
  end
  nil
end

.setup ⇒ Object

Performs all the setup needed for automated firmware upload.

Returns a false value in case of success, or a string with error information if something goes wrong.



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# File 'lib/xilinx/provision/cable_firmware.rb', line 20

def self.setup
  if output = configure_udev
    return "Error while configuring firmware upload udev rules\n#{output}"
  elsif output = Xilinx::Provision::Udev.reload_rules
    return "Error while loading firmware upload udev rules\n#{output}"
  end
  nil
end

.udev_rules ⇒ Object

Rules for the udev daemon to allow non-root access to the USB cable.

Returns an array of rules to be written to a udev file.



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# File 'lib/xilinx/provision/cable_firmware.rb', line 39

def self.udev_rules
  return nil unless path = rules_path
  old_rules = File.read(rules_path).split("\n")
  upgrade_rules old_rules, path
end

.upgrade_rules(old_rules, rules_path) ⇒ Object

Returns a



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# File 'lib/xilinx/provision/cable_firmware.rb', line 46

def self.upgrade_rules(old_rules, rules_path)
  rules_dir = File.dirname rules_path
  old_rules.map do |old_rule|
    rule = old_rule.dup
    # Update old udev syntax.
    [['TEMPNODE', 'tempnode'], ['SYSFS', 'ATTRS'],
     ['BUS', 'SUBSYSTEMS']].each { |from, to| rule.gsub! from, to }
    
    # Change firmware file references to point inside Xilinx ISE. It's very
    # rude to copy crap straigt into /usr/share, Xilinx!
    rule.gsub!(/ \S+\.hex /) do |filepath|
      firmware_name = File.basename filepath.strip
      " #{File.join(rules_dir, firmware_name)} "
    end
    
    rule
  end
end