flipper cannot attach

[m4b]

In running last step in readme, on archlinux with all deps installed, led light is green, etc., running:

LD_LIBRARY_PATH=/usr/local/lib/ VERBOSE=true make install-atsam4s

I get a segfault:

cp utils/fdwarf/fdwarf.py build/utils/fdwarf
chmod +x build/utils/fdwarf
arm-none-eabi-gcc -nostartfiles -mcpu=cortex-m4 -Wl,-T carbon/atsam4s/sam4s16.ld -Wl,--gc-sections -o build/atsam4s/atsam4s.elf build/atsam4s/carbon/atsam4s/modules.c.o build/atsam4s/carbon/atsam4s/led.c.o build/atsam4s/carbon/atsam4s/rtc.c.o build/atsam4s/carbon/atsam4s/uart0.c.o build/atsam4s/carbon/atsam4s/pwm.c.o build/atsam4s/carbon/atsam4s/i2c.c.o build/atsam4s/carbon/atsam4s/dac.c.o build/atsam4s/carbon/atsam4s/system.c.o build/atsam4s/carbon/atsam4s/usb.c.o build/atsam4s/carbon/atsam4s/spi.c.o build/atsam4s/carbon/atsam4s/swd.c.o build/atsam4s/carbon/atsam4s/temp.c.o build/atsam4s/carbon/atsam4s/gpio.c.o build/atsam4s/carbon/atsam4s/main.c.o build/atsam4s/carbon/atsam4s/button.c.o build/atsam4s/carbon/atsam4s/is25lp.c.o build/atsam4s/carbon/atsam4s/fs.c.o build/atsam4s/carbon/atsam4s/adc.c.o build/atsam4s/carbon/atsam4s/timer.c.o build/atsam4s/carbon/atsam4s/fld.c.o build/atsam4s/carbon/atsam4s/usart.c.o build/atsam4s/carbon/atsam4s/wdt.c.o build/atsam4s/kernel/arch/armv7/syscalls.c.o build/atsam4s/kernel/arch/armv7/loader.c.o build/atsam4s/kernel/arch/armv7/scheduler.c.o build/atsam4s/kernel/arch/armv7/exceptions.c.o build/atsam4s/kernel/arch/armv7/vectors.c.o build/atsam4s/kernel/arch/armv7/pendsv.S.o build/atsam4s/runtime/arch/armv7/fmr.S.o build/atsam4s/runtime/src/message.c.o build/atsam4s/runtime/src/endpoint.c.o build/atsam4s/runtime/src/crc.c.o build/atsam4s/runtime/src/error.c.o build/atsam4s/runtime/src/led.c.o build/atsam4s/runtime/src/observer.c.o build/atsam4s/runtime/src/rtc.c.o build/atsam4s/runtime/src/task.c.o build/atsam4s/runtime/src/uart0.c.o build/atsam4s/runtime/src/ll.c.o build/atsam4s/runtime/src/fmr.c.o build/atsam4s/runtime/src/runtime.c.o build/atsam4s/runtime/src/usb.c.o build/atsam4s/runtime/src/spi.c.o build/atsam4s/runtime/src/swd.c.o build/atsam4s/runtime/src/temp.c.o build/atsam4s/runtime/src/gpio.c.o build/atsam4s/runtime/src/pwm.c.o build/atsam4s/runtime/src/event.c.o build/atsam4s/runtime/src/button.c.o build/atsam4s/runtime/src/module.c.o build/atsam4s/runtime/src/i2c.c.o build/atsam4s/runtime/src/fld.c.o build/atsam4s/runtime/src/adc.c.o build/atsam4s/runtime/src/timer.c.o build/atsam4s/runtime/src/dac.c.o build/atsam4s/runtime/src/usart.c.o build/atsam4s/runtime/src/wdt.c.o build/atsam4s/carbon/atsam4s/drivers/pmc/sleep.c.o build/atsam4s/carbon/atsam4s/drivers/pmc/pmc.c.o build/atsam4s/carbon/atsam4s/drivers/acc/acc.c.o build/atsam4s/carbon/atsam4s/drivers/dacc/dacc.c.o build/atsam4s/carbon/atsam4s/drivers/tc/tc.c.o build/atsam4s/carbon/atsam4s/drivers/twi/twi.c.o build/atsam4s/carbon/atsam4s/drivers/chipid/chipid.c.o build/atsam4s/carbon/atsam4s/drivers/pio/pio.c.o build/atsam4s/carbon/atsam4s/drivers/pio/pio_handler.c.o build/atsam4s/carbon/atsam4s/drivers/wdt/wdt.c.o build/atsam4s/carbon/atsam4s/drivers/gpbr/gpbr.c.o build/atsam4s/carbon/atsam4s/drivers/supc/supc.c.o build/atsam4s/carbon/atsam4s/drivers/crccu/crccu.c.o build/atsam4s/carbon/atsam4s/drivers/uart/uart.c.o build/atsam4s/carbon/atsam4s/drivers/rstc/rstc.c.o build/atsam4s/carbon/atsam4s/drivers/adc/adc.c.o build/atsam4s/carbon/atsam4s/drivers/pwm/pwm.c.o build/atsam4s/carbon/atsam4s/drivers/matrix/matrix.c.o build/atsam4s/carbon/atsam4s/drivers/spi/spi.c.o build/atsam4s/carbon/atsam4s/drivers/efc/efc.c.o build/atsam4s/carbon/atsam4s/drivers/usart/usart.c.o build/atsam4s/carbon/atsam4s/drivers/ssc/ssc.c.o build/atsam4s/carbon/atsam4s/drivers/rtt/rtt.c.o build/atsam4s/carbon/atsam4s/drivers/pdc/pdc.c.o build/atsam4s/carbon/atsam4s/drivers/rtc/rtc.c.o
arm-none-eabi-objcopy -O binary build/atsam4s/atsam4s.elf build/atsam4s/atsam4s.bin
build/utils/fdfu build/atsam4s/atsam4s.bin
make: *** [makefile:77: install-atsam4s] Segmentation fault (core dumped)

Segfault is here due to unchecked pointer deref:

flipper/carbon/hal/atmegau2.c

Line 7 in c20b331

struct _carbon_context *context = device->_ctx;

after the flipper.attach() call (presumably) fails here:

flipper/utils/fdfu/src/main.c

Line 286 in c20b331

struct _lf_device *device = flipper.attach();

Or in the rust example, it panics (for similar reason, the flipper.attach() call does not work for whatever reason).

Is there a step i'm missing?

[georgemorgan]

Looks like a bug caused by not booting the Flipper first. Check out this page to learn how to do that.

I’ll note this bug and fix it in the next push. Thanks!

[m4b]

Hmmm, when I run the dfu-programmer command I get this:

m4b@efrit ::  [ ~/git/flipper ] sudo dfu-programmer atmega32u2 start
dfu-programmer: failed to release interface 0.

and still segfaults when previous make command is run.

Similarly, if I use the osx suggestions and do launch, it does not report and error, but make still segfaults.

Any suggestions?

[m4b]

Ah, plugging and unplugging yielded no error, but make still segfaults:

libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/001/027: Permission denied
libusb: error [_get_usbfs_fd] libusb requires write access to USB device nodes.
make: *** [makefile:77: install-atsam4s] Segmentation fault (core dumped)

Subsequent make invocations segfault; even with sudo.

I then plugged/unplugged, sudo dfu-programmer atmega32u2 start, then make succeeds (I think):

m4b@efrit ::  [ ~/git/flipper ] sudo LD_LIBRARY_PATH=/usr/local/lib/ VERBOSE=true make install-atsam4s
gcc -shared -o build/libflipper/libflipper.so build/libflipper/carbon/hal/atsam4s.c.o build/libflipper/carbon/hal/atmegau2.c.o build/libflipper/carbon/hal/hal.c.o build/libflipper/library/src/libflipper.c.o build/libflipper/library/src/flipper.c.o build/libflipper/runtime/arch/x64/fmr.S.o build/libflipper/library/platforms/posix/usb.c.o build/libflipper/library/platforms/posix/network.c.o build/libflipper/library/platforms/posix/fmr.c.o build/libflipper/runtime/src/message.c.o build/libflipper/runtime/src/endpoint.c.o build/libflipper/runtime/src/crc.c.o build/libflipper/runtime/src/error.c.o build/libflipper/runtime/src/led.c.o build/libflipper/runtime/src/observer.c.o build/libflipper/runtime/src/rtc.c.o build/libflipper/runtime/src/task.c.o build/libflipper/runtime/src/uart0.c.o build/libflipper/runtime/src/ll.c.o build/libflipper/runtime/src/fmr.c.o build/libflipper/runtime/src/runtime.c.o build/libflipper/runtime/src/usb.c.o build/libflipper/runtime/src/spi.c.o build/libflipper/runtime/src/swd.c.o build/libflipper/runtime/src/temp.c.o build/libflipper/runtime/src/gpio.c.o build/libflipper/runtime/src/pwm.c.o build/libflipper/runtime/src/event.c.o build/libflipper/runtime/src/button.c.o build/libflipper/runtime/src/module.c.o build/libflipper/runtime/src/i2c.c.o build/libflipper/runtime/src/fld.c.o build/libflipper/runtime/src/adc.c.o build/libflipper/runtime/src/timer.c.o build/libflipper/runtime/src/dac.c.o build/libflipper/runtime/src/usart.c.o build/libflipper/runtime/src/wdt.c.o -lusb-1.0
cp -r carbon/include/flipper/* build/include/flipper
cp -r library/include/flipper/* build/include/flipper
cp -r runtime/include/flipper/* build/include/flipper
cp library/include/flipper.h build/include
gcc -std=gnu99 -Wall -Wextra -Wno-unused-parameter -fpic -DPOSIX -Icarbon/include -Ilibrary/include -Iruntime/include -I/usr/include/libusb-1.0 -o build/utils/fdfu utils/fdfu/src/*.c -Lbuild/libflipper -lflipper
In file included from utils/fdfu/src/main.c:5:0:
carbon/include/flipper/atsam4s/atsam4s.h:35:0: warning: "LF_VAR" redefined
 #define LF_VAR __attribute__((section(".lf.vars")))
 
In file included from carbon/include/flipper/carbon.h:12:0,
                 from library/include/flipper.h:8,
                 from utils/fdfu/src/main.c:2:
library/include/flipper/posix/posix.h:33:0: note: this is the location of the previous definition
 #define LF_VAR __attribute__((section("__DATA,.lf.vars")))
 
In file included from utils/fdfu/src/main.c:5:0:
carbon/include/flipper/atsam4s/atsam4s.h:36:0: warning: "LF_FUNC" redefined
 #define LF_FUNC __attribute__((section(".lf.funcs")))
 
In file included from carbon/include/flipper/carbon.h:12:0,
                 from library/include/flipper.h:8,
                 from utils/fdfu/src/main.c:2:
library/include/flipper/posix/posix.h:34:0: note: this is the location of the previous definition
 #define LF_FUNC __attribute__((section("__TEXT,.lf.funcs")))
 
gcc -std=gnu99 -Wall -Wextra -Wno-unused-parameter -fpic -DPOSIX -Icarbon/include -Ilibrary/include -Iruntime/include -I/usr/include/libusb-1.0 -o build/utils/fdebug utils/fdebug/src/*.c -lusb-1.0
utils/fdebug/src/main.c: In function ‘main’:
utils/fdebug/src/main.c:39:2: warning: ‘libusb_set_debug’ is deprecated: Use libusb_set_option instead [-Wdeprecated-declarations]
  libusb_set_debug(context, LIBUSB_LOG_LEVEL_ERROR);
  ^~~~~~~~~~~~~~~~
In file included from utils/fdebug/src/main.c:4:0:
/usr/include/libusb-1.0/libusb.h:1300:18: note: declared here
 void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
                  ^~~~~~~~~~~~~~~~
gcc -std=gnu99 -Wall -Wextra -Wno-unused-parameter -fpic -DPOSIX -Icarbon/include -Ilibrary/include -Iruntime/include -I/usr/include/libusb-1.0 -o build/utils/fload utils/fload/src/*.c -Lbuild/libflipper -lflipper
gcc -std=gnu99 -Wall -Wextra -Wno-unused-parameter -fpic -DPOSIX -Icarbon/include -Ilibrary/include -Iruntime/include -I/usr/include/libusb-1.0 -o build/utils/fvm utils/fvm/src/*.c -Lbuild/libflipper -lflipper -ldl
utils/fvm/src/uart0.c: In function ‘uart0_push’:
utils/fvm/src/uart0.c:17:37: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘void *’ [-Wformat=]
  printf("Pushing to the uart0 bus: %s\n", source);
                                    ~^
                                    %p
cp utils/fdwarf/fdwarf.py build/utils/fdwarf
chmod +x build/utils/fdwarf
arm-none-eabi-gcc -nostartfiles -mcpu=cortex-m4 -Wl,-T carbon/atsam4s/sam4s16.ld -Wl,--gc-sections -o build/atsam4s/atsam4s.elf build/atsam4s/carbon/atsam4s/modules.c.o build/atsam4s/carbon/atsam4s/led.c.o build/atsam4s/carbon/atsam4s/rtc.c.o build/atsam4s/carbon/atsam4s/uart0.c.o build/atsam4s/carbon/atsam4s/pwm.c.o build/atsam4s/carbon/atsam4s/i2c.c.o build/atsam4s/carbon/atsam4s/dac.c.o build/atsam4s/carbon/atsam4s/system.c.o build/atsam4s/carbon/atsam4s/usb.c.o build/atsam4s/carbon/atsam4s/spi.c.o build/atsam4s/carbon/atsam4s/swd.c.o build/atsam4s/carbon/atsam4s/temp.c.o build/atsam4s/carbon/atsam4s/gpio.c.o build/atsam4s/carbon/atsam4s/main.c.o build/atsam4s/carbon/atsam4s/button.c.o build/atsam4s/carbon/atsam4s/is25lp.c.o build/atsam4s/carbon/atsam4s/fs.c.o build/atsam4s/carbon/atsam4s/adc.c.o build/atsam4s/carbon/atsam4s/timer.c.o build/atsam4s/carbon/atsam4s/fld.c.o build/atsam4s/carbon/atsam4s/usart.c.o build/atsam4s/carbon/atsam4s/wdt.c.o build/atsam4s/kernel/arch/armv7/syscalls.c.o build/atsam4s/kernel/arch/armv7/loader.c.o build/atsam4s/kernel/arch/armv7/scheduler.c.o build/atsam4s/kernel/arch/armv7/exceptions.c.o build/atsam4s/kernel/arch/armv7/vectors.c.o build/atsam4s/kernel/arch/armv7/pendsv.S.o build/atsam4s/runtime/arch/armv7/fmr.S.o build/atsam4s/runtime/src/message.c.o build/atsam4s/runtime/src/endpoint.c.o build/atsam4s/runtime/src/crc.c.o build/atsam4s/runtime/src/error.c.o build/atsam4s/runtime/src/led.c.o build/atsam4s/runtime/src/observer.c.o build/atsam4s/runtime/src/rtc.c.o build/atsam4s/runtime/src/task.c.o build/atsam4s/runtime/src/uart0.c.o build/atsam4s/runtime/src/ll.c.o build/atsam4s/runtime/src/fmr.c.o build/atsam4s/runtime/src/runtime.c.o build/atsam4s/runtime/src/usb.c.o build/atsam4s/runtime/src/spi.c.o build/atsam4s/runtime/src/swd.c.o build/atsam4s/runtime/src/temp.c.o build/atsam4s/runtime/src/gpio.c.o build/atsam4s/runtime/src/pwm.c.o build/atsam4s/runtime/src/event.c.o build/atsam4s/runtime/src/button.c.o build/atsam4s/runtime/src/module.c.o build/atsam4s/runtime/src/i2c.c.o build/atsam4s/runtime/src/fld.c.o build/atsam4s/runtime/src/adc.c.o build/atsam4s/runtime/src/timer.c.o build/atsam4s/runtime/src/dac.c.o build/atsam4s/runtime/src/usart.c.o build/atsam4s/runtime/src/wdt.c.o build/atsam4s/carbon/atsam4s/drivers/pmc/sleep.c.o build/atsam4s/carbon/atsam4s/drivers/pmc/pmc.c.o build/atsam4s/carbon/atsam4s/drivers/acc/acc.c.o build/atsam4s/carbon/atsam4s/drivers/dacc/dacc.c.o build/atsam4s/carbon/atsam4s/drivers/tc/tc.c.o build/atsam4s/carbon/atsam4s/drivers/twi/twi.c.o build/atsam4s/carbon/atsam4s/drivers/chipid/chipid.c.o build/atsam4s/carbon/atsam4s/drivers/pio/pio.c.o build/atsam4s/carbon/atsam4s/drivers/pio/pio_handler.c.o build/atsam4s/carbon/atsam4s/drivers/wdt/wdt.c.o build/atsam4s/carbon/atsam4s/drivers/gpbr/gpbr.c.o build/atsam4s/carbon/atsam4s/drivers/supc/supc.c.o build/atsam4s/carbon/atsam4s/drivers/crccu/crccu.c.o build/atsam4s/carbon/atsam4s/drivers/uart/uart.c.o build/atsam4s/carbon/atsam4s/drivers/rstc/rstc.c.o build/atsam4s/carbon/atsam4s/drivers/adc/adc.c.o build/atsam4s/carbon/atsam4s/drivers/pwm/pwm.c.o build/atsam4s/carbon/atsam4s/drivers/matrix/matrix.c.o build/atsam4s/carbon/atsam4s/drivers/spi/spi.c.o build/atsam4s/carbon/atsam4s/drivers/efc/efc.c.o build/atsam4s/carbon/atsam4s/drivers/usart/usart.c.o build/atsam4s/carbon/atsam4s/drivers/ssc/ssc.c.o build/atsam4s/carbon/atsam4s/drivers/rtt/rtt.c.o build/atsam4s/carbon/atsam4s/drivers/pdc/pdc.c.o build/atsam4s/carbon/atsam4s/drivers/rtc/rtc.c.o
arm-none-eabi-objcopy -O binary build/atsam4s/atsam4s.elf build/atsam4s/atsam4s.bin
build/utils/fdfu build/atsam4s/atsam4s.bin
Entering update mode.
 Successfully entered update mode.
Entering normal mode.
 Successfully entered normal mode.
Checking security bit.
 Security bit is clear.
Uploading copy applet.
 Successfully uploaded copy applet.
Uploading page 30 / 30. (100.00%)
 Successfully uploaded all pages. 14920 bytes used. (1.42% of flash)
Checking GPNVM1 bit.
The device's GPNVM1 bit is set.
Resetting the CPU.
 Successfully reset the CPU.
----------------------

Would you like to place the CPU in update mode again? ([y]/n): y

Entering update mode.
Failed to enter update mode.

Would you like to reload the target file and flash it? ([y]/n): y

Entering update mode.
Failed to enter update mode.
make: *** [makefile:77: install-atsam4s] Error 1

Should I worry about the above?

[nicholastmosher]

I think your last error arose because you selected y at

Would you like to reload the target file and flash it? ([y]/n): y

That's not anything to worry about. We've actually intended to remove that prompt for awhile, it used to be a convenience due to a bug which caused the flashing process to only work half the time (selecting y simply repeats the flashing process). So in the future just select n at that prompt and the flashing process will be completed successfully.

Currently make install-atsam4s invokes a utility called fdfu, but we're going to be replacing that with the console's flipper flash command. That's all fully operational in master right now, we just have yet to migrate the make command. If you'd like to try out the console version (and you have the rust toolchain installed), you can either run make install-console from the project root or you can navigate to console/ and run cargo install. Then you should be able to run flipper flash <binary>.

[m4b]

I built and installed the flipper cli tool, but not sure which thing to flash; I tried various things, like:

sudo LD_LIBRARY_PATH=/usr/local/lib flipper flash --verify build/atsam4s/atsam4s.bin

but this returns "cannot attach to device"

And now plugging and replugging device, running dfu-programmer start, etc., and then make install-atsam4s always segfaults at same spot. Could there be something wrong with my board? Confused about what to do at this point.

[georgemorgan]

Have you tried flashing but without pressing y when asked if you would like to enter update mode again? Also, I'm unsure why dfu-programmer is reporting that it can't release interface 0, but I read somewhere that this can be safely ignored.

[m4b]

No, because it doesn't even get that far, below is unplugged then plugged in:

m4b@efrit ::  [ ~/git/flipper ] sudo make install-atmegau2
Checking memory from 0x0 to 0x6FFF...  Not blank at 0x1.
Erasing flash...  Success
Checking memory from 0x0 to 0x6FFF...  Empty.
Checking memory from 0x0 to 0x167F...  Empty.
0%                            100%  Programming 0x1680 bytes...
[>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>]  Success
0%                            100%  Reading 0x7000 bytes...
[>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>]  Success
Validating...  Success
0x1680 bytes written into 0x7000 bytes memory (20.09%).
m4b@efrit ::  [ ~/git/flipper ] sudo LD_LIBRARY_PATH=/usr/local/lib make install-atsam4s
In file included from utils/fdfu/src/main.c:5:0:
carbon/include/flipper/atsam4s/atsam4s.h:35:0: warning: "LF_VAR" redefined
 #define LF_VAR __attribute__((section(".lf.vars")))
 
In file included from carbon/include/flipper/carbon.h:12:0,
                 from library/include/flipper.h:8,
                 from utils/fdfu/src/main.c:2:
library/include/flipper/posix/posix.h:33:0: note: this is the location of the previous definition
 #define LF_VAR __attribute__((section("__DATA,.lf.vars")))
 
In file included from utils/fdfu/src/main.c:5:0:
carbon/include/flipper/atsam4s/atsam4s.h:36:0: warning: "LF_FUNC" redefined
 #define LF_FUNC __attribute__((section(".lf.funcs")))
 
In file included from carbon/include/flipper/carbon.h:12:0,
                 from library/include/flipper.h:8,
                 from utils/fdfu/src/main.c:2:
library/include/flipper/posix/posix.h:34:0: note: this is the location of the previous definition
 #define LF_FUNC __attribute__((section("__TEXT,.lf.funcs")))
 
utils/fdebug/src/main.c: In function ‘main’:
utils/fdebug/src/main.c:39:2: warning: ‘libusb_set_debug’ is deprecated: Use libusb_set_option instead [-Wdeprecated-declarations]
  libusb_set_debug(context, LIBUSB_LOG_LEVEL_ERROR);
  ^~~~~~~~~~~~~~~~
In file included from utils/fdebug/src/main.c:4:0:
/usr/include/libusb-1.0/libusb.h:1300:18: note: declared here
 void LIBUSB_CALL libusb_set_debug(libusb_context *ctx, int level);
                  ^~~~~~~~~~~~~~~~
utils/fvm/src/uart0.c: In function ‘uart0_push’:
utils/fvm/src/uart0.c:17:37: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘void *’ [-Wformat=]
  printf("Pushing to the uart0 bus: %s\n", source);
                                    ~^
                                    %p
make: *** [makefile:77: install-atsam4s] Segmentation fault (core dumped)

[georgemorgan]

I’m having trouble reproducing this issue. Can you provide details about your environment? Also, what version of libusb are you using?

Once the device is plugged in try lsusb and see if you can see your device in DFU mode as “Atmel ATMega32u2 DFU”. Boot it and run lsusb command again and ensure you can see the “Flipper: Carbon” device.

I will of course need to submit a PR to do the NULL pointer check, but I can’t figure out why this is NULL in the first place for you.

[m4b]

@georgemorgan thanks for looking into this!

So some system info, I'm running archlinux:

Linux efrit 4.16.4-1-ARCH #1 SMP PREEMPT Tue Apr 24 13:21:29 UTC 2018 x86_64 GNU/Linux

Name            : dfu-programmer
Version         : 0.7.2-1

Name            : libusb
Version         : 1.0.22-1

Plugging device in first time:

m4b@efrit ::  [ ~/git/flipper ] lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 03eb:214e Atmel Corp. 
Bus 001 Device 003: ID 2232:1080 Silicon Motion 
Bus 001 Device 002: ID 0cf3:e500 Qualcomm Atheros Communications 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

So device isn't there/recognized.

I reboot, after reboot:

m4b@efrit ::  [ ~/git/flipper ] lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 005: ID 03eb:214e Atmel Corp. 
Bus 001 Device 004: ID 2232:1080 Silicon Motion 
Bus 001 Device 003: ID 0cf3:e500 Qualcomm Atheros Communications 
Bus 001 Device 002: ID 03eb:2ff0 Atmel Corp. atmega32u2 DFU bootloader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
m4b@efrit ::  [ ~/git/flipper ] dfu-programmer atmega32u2 start
dfu-programmer: no device present.

So uh, that's fucking weird? I dunno wth is going on.

I can start device as normal on macbook, using dfu-programmer atmega32u2 start (using same dfu-programmer version, 0.7.2), and even flash the led using the rust example, without issue, so I don't think the device is dead or the cable is messed up? ...

[georgemorgan]

I'm really unsure what is going on here. I am unable to repro this issue on Linux or OS X.

If you can interact with the device from a MacBook, then the hardware is working. There must be some discrepancy with this specific Linux distro that I can't seem to figure out.

[WillNilges]

I am also having this exact issue with Arch.