Skip to content

Latest commit

 

History

History
109 lines (83 loc) · 3.63 KB

debugging.md

File metadata and controls

109 lines (83 loc) · 3.63 KB
Raw

OpenSK logo

Troubleshooting and Debugging

Inspecting USB

The following commands should help you identify whether your operating system identifies OpenSK over USB.

Linux

When plugging in the USB key, the following line should appear in lsusb.

$ lsusb
...
Bus XXX Device YYY: ID 1915:521f Nordic Semiconductor ASA OpenSK

You should also see lines similar to the following in dmesg.

$ dmesg
...
[XXX] usb A-BB: new full-speed USB device number 00 using xhci_hcd
[XXX] usb A-BB: New USB device found, idVendor=1915, idProduct=521f, bcdDevice= 0.01
[XXX] usb A-BB: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[XXX] usb A-BB: Product: OpenSK
[XXX] usb A-BB: Manufacturer: Nordic Semiconductor ASA
[XXX] usb A-BB: SerialNumber: v0.1
[XXX] hid-generic 0000:0000:0000.0000: hiddev0,hidraw0: USB HID v1.10 Device [Nordic Semiconductor ASA OpenSK] on usb-0000:00:00.0-00/input0

Mac OS X

When plugging in the USB key, you should see a similar line by using the ioreg tool:

$ ioreg -p IOUSB
+-o Root  <class IORegistryEntry, id 0x100000100, retain 21>
...
  +-o AppleUSBXHCI Root Hub Simulation@14000000  <class AppleUSBRootHubDevice, id 0x100000a00, registered, matched, active, busy 0 (0 ms), retain 9>
    +-o OpenSK@14400000  <class AppleUSBDevice, id 0x100003c04, registered, matched, active, busy 0 (0 ms), retain 13>

Debug console

On the dev board, you can read the debug messages using JLink. Use one terminal for the server and one for the client:

# Terminal 1
JLinkExe -device nrf52 -if swd -speed 1000 -autoconnect 1
# Terminal 2
JLinkRTTClient

You can enhance the debug output by adding flags to the deploy command (see below for details):

  • --debug: more debug messages
  • --panic-console: add panic messages
  • --debug-allocations: print information about the used heap

Adding debugging to your firmware increases resource usage, including

  • USB communication speed
  • RAM usage
  • binary size

Depending on your choice of board, you may have to increase the available stack for kernel or app, or disable features so that the binary fits the flash. Also expect more packet loss.

App panic messages

By default, libtock-rs blinks some LEDs when the userspace application panics. This is not always convenient as the panic message is lost. In order to enable a custom panic handler that first writes the panic message via Tock's console driver, before faulting the app, you can use the --panic-console flag of the deploy.py script.

# Example on Nordic nRF52840-DK board
./deploy.py --board=nrf52840dk_opensk --opensk --panic-console

Memory allocations

You may want to track memory allocations to understand the heap usage of OpenSK. This can be useful if you plan to port it to a board with fewer available RAM for example. To do so, you can enable the --debug-allocations flag of the deploy.py script. This enables a custom (userspace) allocator that prints a message to the console for each allocation and deallocation operation.

The additional output looks like the following.

# Allocation of 256 byte(s), aligned on 1 byte(s). The allocated address is
# 0x2002401c. After this operation, 2 pointers have been allocated, totalling
# 384 bytes (the total heap usage may be larger, due to alignment and
# fragmentation of allocations within the heap).
alloc[256, 1] = 0x2002401c (2 ptrs, 384 bytes)
# Deallocation of 64 byte(s), aligned on 1 byte(s), from address 0x2002410c.
# After this operation, 1 pointers are allocated, totalling 512 bytes.
dealloc[64, 1] = 0x2002410c (1 ptrs, 512 bytes)