Memory Use Analysis

Use the approaches below to show memory use for an executable. In the examples below, we compile the gcoap example app for samr21-xpro.

Flash Storage

The command below shows the full executable size as well as the size of compiled modules. You likely will want to focus in on a subset of the modules.

$ DEVELHELP=0 BOARD=samr21-xpro make clean all

   text	   data	    bss	    dec	    hex	filename
  66640	    920	  16328	  83888	  147b0	/home/kbee/dev/riot/repo/examples/gcoap/bin/samr21-xpro/gcoap

$ DEVELHELP=0 BOARD=samr21-xpro make info-objsize |grep gcoap

   2799	    392	   1298	   4489	   1189	gcoap.o (ex /gcoap.a)
   1778	     12	      2	   1792	    700	gcoap_cli.o (ex /application_gcoap_example.a)
    150	      0	     32	    182	     b6	main.o (ex /application_gcoap_example.a)

The command below further breaks down flash use to show the size of individual functions.

arm-none-eabi-nm -Sn -t d bin/samr21-xpro/gcoap_example.elf |grep gcoap |awk '{printf "%5u %s %s\n", $2, $3, $4}'

  656 T gcoap_cli_cmd
   16 T gcoap_cli_init
  148 T gcoap_init
   24 T gcoap_register_listener
  100 T gcoap_req_init
   92 T gcoap_finish
  368 T gcoap_req_send2
   78 T gcoap_resp_init
  120 T gcoap_obs_init
   52 T gcoap_obs_send
   24 T gcoap_op_state
  140 T gcoap_get_resource_list

RAM Use

Use the ps command to show allocated memory per thread stack as well as memory used. Must compile with DEVELHELP=1 (usually the default) to see this level of detail.

The command can be called from the CLI with ps, or programmatically with ps().

pid | name                 | state    Q | pri | stack  ( used) | base addr  | current     
  - | isr_stack            | -        - |   - |   8192 (   -1) | 0x566775c0 | 0x566775c0
  1 | idle                 | pending  Q |  15 |   8192 (  420) | 0x566752e0 | 0x56677154 
  2 | main                 | running  Q |   7 |  12288 ( 3008) | 0x566722e0 | 0x56675154 
  3 | ipv6                 | bl rx    _ |   4 |   8192 ( 1680) | 0x566857e0 | 0x56687654 
  4 | udp                  | bl rx    _ |   5 |   8192 ( 1008) | 0x56681700 | 0x56683574 
  5 | coap                 | bl mbox  _ |   6 |   8276 ( 1572) | 0x5667dce0 | 0x5667fba8 
  6 | gnrc_netdev_tap      | bl rx    _ |   2 |   8192 ( 2352) | 0x566837c0 | 0x56685634 
    | SUM                  |            |     |  61524 (10040)