memory.md

Memory access

The memory subsystem allows reading and writing raw binary data to various memories and memory-mapped functionalities in the Crazyflie. In the Crazyflie CLI the mem command is used to access the memory subsystem as raw binary data. Some memories also support decoding of the data by using the display parameter.

Note that all command accept both decimal and hexadecimal (prefix 0x) values for address, size and data parameters.

For documentation on the memory sub system and the various memory types see this link

Listing memories

To list all the available memories in the Crazyflie use the following command:

cfcli mem list

This will show an output similar to the one below showing id, type, size and serial (if available):

Memories:
[0] EEPROMConfig size=7k (0x1fff/8191)
[1] Trajectory size=4k (0x1000/4096)
[2] MemoryTester size=4k (0x1000/4096)
[3] DeckCtrl size=2k (0x800/2048) (0x2D0043000550314854363720)
[4] DeckMemory size=1310720k (0x50000000/1342177280)
[5] DeckCtrlDFU size=96k (0x18000/98304)

Reading memory

To read raw binary data from a memory use the following commands:

cfcli mem read 0 0x00 0x20

This will read 0x20 (32) bytes from memory ID 0 starting at address 0x00. The output will look simlar to this:

0000:   30 78 42 43 01 3c 02 00 00 00 00 00 00 00 00 e7   0xBC.<..........
0010:   e7 e7 e7 e7 ef ff ff ff ff ff ff ff ff ff ff ff   ................

It's also possible to write the data to a file direclyly using the --output parameter:

cfcli mem read 0 0x00 0x20 --output memory_dump.bin

Writing memory

To write raw binary data to the memory use the following command. This will write the data 1,2,3 to the memory with ID 0 start at the address 0x20.

cfcli mem write 0 0x20 --data 0x01,1,0x02

It's also possible to write data from a file using the --input parameter:

cfcli mem write 0 0x20 --input memory_data.bin

Note: The Crazyflie will most likely not like writing raw random data to memories, so when using this functionality make sure you know what you are doing!

Displaying memory

This command is used to interpret and display the content of a memory. Note that not all memories support this functionality.

cfcli mem display 6

This will give an output similar to this:

EEPROM Config:
  Radio Channel: 60
  Radio Speed: 2 Mbps
  Pitch Trim: 0.0000
  Roll Trim: 0.0000
  Radio Address: [E7, E7, E7, E7, E7]

Example usage

Below is an example of how to use the raw memory access to bootload the Color LED deck (the DeckMemory is on ID 3).

# Switch the deck into bootloader mode
cfcli mem write 3 0x1004 --data 0x02
# Write the firmware binary to the deck memory
cfcli mem write 3 0x10000000 --input color-led.bin
# Switch the deck back into application mode
cfcli mem write 3 0x1004 --data 0x01