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6b8c0633bc
- drop Travis support (now defunct)
- generic_cpp.mk: use -std=c++17 (requires gcc 7.3 or later)
- RlinkPortCuff : drop libusb_set_debug (now deprecated)
- viv_tools_config.tcl: use open_hw_manager
- vbomconv: ghdl_m: use -Wl,--no-pie (for UB 18.04 gcc)
- simlib.vhd: write{oct,hex}: fix for ghdl V0.36 -Whide warnings
47 lines
1.6 KiB
Markdown
47 lines
1.6 KiB
Markdown
This directory contains [udev](https://en.wikipedia.org/wiki/Udev) rule files
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which ensure that
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- FTDI based USB UARTs are operated with low latency
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- Digilent FT2232C style FPGA boards receive a persistent device name
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Each Digilent FT2232C style FPGA board has a unique serial number
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of the USB interface. This can be used to assign a human readable alias
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of the form `/dev/fpga_...` to a board.
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The file [92-retro-usb-persistent.rules](92-retro-usb-persistent.rules)
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contains _example rules_ valid for the boards of the author.
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**This file must be adopted to the available boards before it is used.**
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Use
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```bash
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udevadm info -q all -n /dev/ttyUSB1
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#
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# /dev/ttyUSB1 is correct if the FPGA board is the only USB tty device.
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# If you have other USB tty devices adopt to your needs
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#
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```
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to determine the `ID_SERIAL_SHORT` and create rules for your boards.
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To setup udev rules do
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```bash
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cd $RETROBASE/tools/sys
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# !! adopt 92-retro-usb-persistent.rules to your needs !!
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sudo cp -a 91-retro-usb-latency.rules /etc/udev/rules.d/
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sudo cp -a 92-retro-usb-persistent.rules /etc/udev/rules.d/
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sudo chown root:root /etc/udev/rules.d/*-retro-usb-*.rules
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ls -al /etc/udev/rules.d/
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sudo udevadm control --reload-rules
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```
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to verify whether usb device has low latency use
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```bash
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# --> deterime the /dev/ttyUSB* device of interest
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cat /sys/bus/usb-serial/devices/ttyUSB1/latency_timer
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# --> should show '1' and not '16'
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```
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and to verify whether persistent device name are applied use
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```bash
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ls -al /dev/fpga_*
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# output like
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# lrwxrwxrwx 1 root root 7 2020-03-15 13:55 /dev/fpga_arty -> ttyUSB1
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```
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