# Frequently Asked Build Questions
-This page covers questions about building QMK. If you have not yet you should read the [Build Guide](https://github.com/qmk/qmk_firmware/blob/master/docs/build_guide.md).
+This page covers questions about building QMK. If you haven't yet done so, you should read the [Build Environment Setup](getting_started_build_tools.md) and [Make Instructions](getting_started_make_guide.md) guides.
-In short,
+## Can't Program on Linux
+You will need proper permissions to operate a device. For Linux users, see the instructions regarding `udev` rules, below. If you have issues with `udev`, a work-around is to use the `sudo` command. If you are not familiar with this command, check its manual with `man sudo` or [see this webpage](https://linux.die.net/man/8/sudo).
- $ make [-f Makefile.<variant>] [KEYMAP=...] clean
- $ make [-f Makefile.<variant>] [KEYMAP=...]
- $ make [-f Makefile.<variant>] [KEYMAP=...] dfu
+An example of using `sudo`, when your controller is ATMega32u4:
-
-## Can't program on Linux
-You will need proper permission to operate a device. For Linux users see udev rules below.
-Easy way is to use `sudo` command, if you are not familiar with this command check its manual with `man sudo` or this page on line.
-
-In short when your controller is ATMega32u4,
-
$ sudo dfu-programmer atmega32u4 erase --force
$ sudo dfu-programmer atmega32u4 flash your.hex
$ sudo dfu-programmer atmega32u4 reset
-or just
-
- $ sudo make dfu
+or just:
-But to run `make` with root privilege is not good idea. Use former method as possible.
+ $ sudo make <keyboard>:<keymap>:dfu
-## WINAVR is obsolete
-It is no longer recommended and may cause some problem.
-See [Issue #99](https://github.com/tmk/tmk_keyboard/issues/99).
+Note that running `make` with `sudo` is generally *not* a good idea, and you should use one of the former methods, if possible.
-## USB VID and PID
-You can use any ID you want with editing `config.h`. Using any presumably unused ID will be no problem in fact except for very least chance of collision with other product.
-
-Most boards in QMK use `0xFEED` as the vendor ID. You should look through other keyboards to make sure you pick a unique Product ID.
-
-Also see this.
-https://github.com/tmk/tmk_keyboard/issues/150
-
-You can buy a really unique VID:PID here. I don't think you need this for personal use.
-- http://www.obdev.at/products/vusb/license.html
-- http://www.mcselec.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=92&option=com_phpshop&Itemid=1
-
-
-## Linux udev rules
-On Linux you need proper privilege to access device file of MCU, you'll have to use `sudo` when flashing firmware. You can circumvent this with placing these files in `/etc/udev/rules.d/`.
+## Linux `udev` Rules
+On Linux, you'll need proper privileges to access the MCU. You can either use
+`sudo` when flashing firmware, or place these files in `/etc/udev/rules.d/`.
**/etc/udev/rules.d/50-atmel-dfu.rules:**
```
SUBSYSTEMS=="usb", ATTRS{idVendor}=="feed", MODE:="0666"
```
+## WINAVR is Obsolete
+It is no longer recommended and may cause some problem.
+See [TMK Issue #99](https://github.com/tmk/tmk_keyboard/issues/99).
+
+## USB VID and PID
+You can use any ID you want with editing `config.h`. Using any presumably unused ID will be no problem in fact except for very low chance of collision with other product.
+
+Most boards in QMK use `0xFEED` as the vendor ID. You should look through other keyboards to make sure you pick a unique Product ID.
-## Cortex: cstddef: No such file or directory
+Also see this.
+https://github.com/tmk/tmk_keyboard/issues/150
+
+You can buy a really unique VID:PID here. I don't think you need this for personal use.
+- http://www.obdev.at/products/vusb/license.html
+- http://www.mcselec.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=92&option=com_phpshop&Itemid=1
+
+## Cortex: `cstddef: No such file or directory`
GCC 4.8 of Ubuntu 14.04 had this problem and had to update to 4.9 with this PPA.
https://launchpad.net/~terry.guo/+archive/ubuntu/gcc-arm-embedded
https://github.com/tmk/tmk_keyboard/wiki/mbed-cortex-porting#compile-error-cstddef
https://developer.mbed.org/forum/mbed/topic/5205/
-
-## 'clock_prescale_set' and 'clock_div_1' not available
+## `clock_prescale_set` and `clock_div_1` Not Available
Your toolchain is too old to support the MCU. For example WinAVR 20100110 doesn't support ATMega32u2.
```
Note that Teensy2.0++ bootloader size is 2048byte. Some Makefiles may have wrong comment.
```
-# Boot Section Size in *bytes*
-# Teensy halfKay 512
-# Teensy++ halfKay 2048
+# Boot Section Size in *bytes*
+# Teensy halfKay 512
+# Teensy++ halfKay 2048
# Atmel DFU loader 4096 (TMK Alt Controller)
-# LUFA bootloader 4096
-# USBaspLoader 2048
+# LUFA bootloader 4096
+# USBaspLoader 2048
OPT_DEFS += -DBOOTLOADER_SIZE=2048
```
+
+## `avr-gcc: internal compiler error: Abort trap: 6 (program cc1)` on MacOS
+This is an issue with updating on brew, causing symlinks that avr-gcc depend on getting mangled.
+
+The solution is to remove and reinstall all affected modules.
+
+```
+brew rm avr-gcc
+brew rm dfu-programmer
+brew rm gcc-arm-none-eabi
+brew rm avrdude
+brew install avr-gcc
+brew install dfu-programmer
+brew install gcc-arm-none-eabi
+brew install avrdude
+```
+
+### avr-gcc 8.1 and LUFA
+
+If you updated your avr-gcc to above 7 you may see errors involving LUFA. For example:
+
+`lib/lufa/LUFA/Drivers/USB/Class/Device/AudioClassDevice.h:380:5: error: 'const' attribute on function returning 'void'`
+
+For now, you need to rollback avr-gcc to 7 in brew.
+
+```
+brew uninstall --force avr-gcc
+brew install avr-gcc@7
+brew link avr-gcc@7
+```
projects / qmk_firmware.git / blobdiff