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Hi guys, I'm programming some stand-alone audio application on the TMS320C6713 DSK. It has 256 KB of usable flash memory. It's not bad but i'd like to have as much free space as possible on the flash, to put the maximum amount of my tiny musics. My original executable code is about 140 KB big. My idea is to compress it, for example by using the z library ( http://www.gzip.org/zlib/ ). Then i would have a tiny piece of code that would basically boot the C zlib decompressor executable. It will then be my task to decompress my "big" executable and to place the sections at their correct addresses in IRAM/SDRAM, being careful with potential overwrite issues. Then i should be able to call the entry point routine of my program. Do you think it makes sense ? I think compressing the executable is kinda neat, it has been done for ages on old 8 & 16/32 bits computers ( like Commodore 64 & Amiga ). Did some of you already think about doing something similar, what kind of compression library did you use, and what kind of issue did you meet ? Thanks, Laurent |
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Loading compressed executable from flash
Started by ●June 21, 2004
Reply by ●June 22, 20042004-06-22
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> Did some of you already think about doing something similar, what kind of > compression library did you use, and what kind of issue did you meet ? Hi Laurent, Some years ago, I had implemented this kind of solution on a MIPS platform. It worked great. If I remember well, I had taken the zLib compression library (you should find the source code easily). I had made a small tool that took the .bin, compressed it, added checksums and some loading info, and converted all this to a very big byte array in a .c file. Then, this file was compiled and linked together with a kind of bootloader, that was able to uncompress the code into RAM and jump to it. As far as I know, there should be no problem for doing this on TI DSPs. You have to take care of some aspects, like cache coherency when jumping to the new code, and vector table pointer (ISTP on C64x DSP's). Regards J-F |
Reply by ●June 22, 20042004-06-22
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Hello J-F, Thanks for your answer ! I've found a very interesting compression library to achieve all this. It's called UCL : http://www.oberhumer.com/opensource/ucl/ As the author says : UCL is written in ANSI C. Both the source code and the compressed data format are designed to be portable across platforms. UCL implements a number of algorithms with the following features: * Decompression is simple and *very* fast. * Requires no memory for decompression. * The decompressors can be squeezed into less than 200 bytes of code. ... UCL's decompressors should work on any system around - they could even get ported to 8-bit processors such as the Z-80 or 6502. I don't know if the achieved compression ratio is as good as gzip or bzip2 ( i actually don't think so ), but i think the 3 points mentioned above makes UCL a well adapted tool to address this particular issue :) Cheers, Laurent > Hi Laurent, > > Some years ago, I had implemented this kind of solution on a MIPS > platform. > It worked great. If I remember well, I had taken the zLib > compression library (you should find the source code easily). > I had made a small tool that took the .bin, compressed > it, added checksums and some loading info, and converted all this to > a very big byte array in a .c file. Then, this file was compiled > and linked together with a kind of bootloader, that was able to > uncompress the code into RAM and jump to it. > > As far as I know, there should be no problem for doing this on > TI DSPs. > You have to take care of some aspects, like cache coherency when > jumping to the new code, and vector table pointer (ISTP on C64x > DSP's). > > Regards > > J-F > > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: Send an email to > > To Post: Send an email to > > To Leave: Send an email to > > Archives: http://www.yahoogroups.com/group/c6x > > Other Groups: http://www.dsprelated.com > > Yahoo! Groups Links > |
