Posted on October 24, 2011 at 09:45We use the feature ''run external program'' in Keil: Project Properties, Tab ''User''.
The checksum is calculated by the srecord tools (http://srecord.sf.net) and added to both hex file and axf file. The axf file is a little tricky, you need to find the correct offset in the axf file to put the checksum. Since our checksum is at address 0x8000000 (replacing the reset stack pointer) this was fairly simple.
An example batch file for using srecord tools to put the checksum in an intel hex file at address 0x8000000 is:
rem set some defaults:
rem srecord tools are in ''tools'' subdirectory of current Keil project
set srec_''cat=tools\srec_cat.exe''
rem objectdir-Path is where the hex-file is stored (relative to project dir)
set objdir=''obj''
rem Filename of Hex File
set Hex_File=''h200ng.hex''
rem Start adress in FLASH
set /a start=0x08000000
rem Offset in FLASH (if you want CRC not at the beginning, but elsewhere
set /a _CRC_Chksum_Address_Offset = start
set /a _CRC16_Chksum_Address_End = _CRC_Chksum_Address_Offset + 0x2
set /a _CRC_Chksum_Address_End = _CRC_Chksum_Address_Offset + 0x4
::::::::::::::::::::::::::::::::::::::::::::::::
rem calculate CRC of Intel Hex File and save in file
::::::::::::::::::::::::::::::::::::::::::::::::
%srec_cat% %objdir%/%Hex_File% -Intel -Exclude %_CRC_Chksum_Address_Offset% %_CRC_Chksum_Address_End% -Little_Endian_CRC16 %_CRC_Chksum_Address_Offset% -broken -Fill 0x00 %_CRC16_Chksum_Address_End% %_CRC_Chksum_Address_End% -o %objdir%/%Hex_File% -Intel -Line_Length 43
rem ''Exclude'': remove area where CRC is stored from hex file
rem -Little_Endian_CRC16: Calculate and store checksum
rem -Fill: CRC-16 is only 2 Bytes, thus fill the rest with zero
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Admittedly this looks a bit convoluted at first, but the srecord tools are a very powerful set of tools to convert and modify hex files as well as binary files
Definitely worth learning. They replaced a plethora of home-grown tools here.
jens
