RE: DFU HELP - .MAP file to find Application size in Flash

Clem Taylor — Thu, 14 May 2015 03:24:30 GMT

If you are using gcc, then you use the size utility:

arm-none-eabi-size xxxboot.elf
   text	   data	    bss	    dec	    hex	filename
  24862	   1760	  15016	  41638	   a2a6	xxxboot.elf

In my case I just use objcopy to extract the data from the elf and get the size from that (mostly because I already need to extract the data to compute the embedded CRCs).

$ arm-none-eabi-objcopy -Obinary --gap-fill=0xFF xxxboot.elf xxxboot.bin
$ stat -c %s xxxboot.bin 
26624

I use the linker file to pad the data out to the maximum section size. So the size is always 26624, but if I extract just the filler section I can figure out how much space is 'free'.

$ arm-none-eabi-objcopy -Obinary -j .fill xxxboot.elf xxxfill.bin
$ stat -c %s xxxfill.bin 
1660

The final step in my .elf compile rule prints:

xxxboot.elf: 1660 free of 26620 CRC: fcb4576c

I generate a map file but parsing it is a bit of a pain, so instead I use a combination of 'nm' and 'readelf' to pull out interesting data.

I have a script 'elfFlash' which will find out where all your flash is going:

#!/bin/sh
# print all non-empty symbols in flash (addresses beginning in 0x00??????)
ME="${0##*/}" # my name
elf=$1

if [ $# -ne 1 -o ! -x "$1" ]; then
    echo "Usage: $ME <elf file>"
    exit
fi

arm-none-eabi-readelf --wide --symbols $elf | \
    awk '$2 ~/^00/ && $3 != 0' | \
    sed 's/^[ 0-9]\+:\s\+//' | \
    sort | uniq -w 8

exit 0

This just pulls all the symbols in the elf file, picks out symbols whose address starts with 0x00 and whose size is non-zero. Then it sorts by address and strips out duplicate (overlapping) symbols.

You can also sort by size with 'sort -k2nr' to find the big size offenders.

FWI, if you are using '-Os -flto' the size of various functions can be a bit miss-leading because gcc will recursively collapse leaf functions, so things like main() and your BLE event handlers can be end up being fairly large.

If you are interested in symbols that end up in SRAM you can do something like:

arm-none-eabi-readelf --wide --symbols $elf | \
    awk '$2 ~/^20/ && $3 != 0 && $4 ~/OBJECT/' | \
    sed 's/^[ 0-9]\+:\s\+//' | \
    sort | uniq -w 8

RE: DFU HELP - .MAP file to find Application size in Flash

Hung Bui — Fri, 08 May 2015 08:39:00 GMT

@Dave: Correct, the .bin file tell the size of the code. If you use gcc, you can also use arm-none-eabi-size.exe [.out file ] to find the size of the code (text+data). Have a look here.

RE: DFU HELP - .MAP file to find Application size in Flash

Dave_couling — Fri, 08 May 2015 05:12:06 GMT

I am using Eclipse with GNU. Could I used the *.bin file size as a guide for the size? I can't seem to find a way to analyze the data in the *.MAP file for indication.

RE: DFU HELP - .MAP file to find Application size in Flash

Hung Bui — Thu, 07 May 2015 13:41:04 GMT

@Dave: If you use KEIL to compile, you can scrool all the way down, and can find the ROM size at the bottom of the .map file: Total ROM Size = Code + RO Data + RW Data

You can also convert your hex/asf file to .bin binary file. The size of the binary file tells the size of actual code on flash.