On Thu, Mar 26, 2009 at 9:52 AM, Jerry Van Baren gerald.vanbaren@ge.com wrote:
Jon Smirl wrote:
My networking hardware needs microcode loaded into it before it will function. What's the best method to load this code? It's 70KB.
My current u-boot image is 170KB. I started working with the code in examples and api_examples. But the "hello world" programs built using those APIs are 65-72KB in size. That's almost half the size of my u-boot image and these programs just print "hello world". Why are these programs so big? My goal was to put the loader program and my microcode into a single 128KB erase block.
My code for loading the microcode into the hardware is 7KB. Now it looks like I will need to incorporate it into the main u-boot image instead of making it an external command.
Hi Jon,
I suspect the example code is 98% C libraries and 2% nugget. In your example, "hello world" probably uses the whole printf support tree (strings, formatted printing, possibly floating point...).
I would suggest you make a stand-alone application that simply returns and see how big it ends up. Depending on whether that is small or not, check what libraries get linked with it and see how to create your simple test app such that it doesn't use any extraneous libraries.
Libraries appear to be the problem. A program that just returns is 100 bytes, add a puts("hello world") and it is 65KB.
I had expected the u-boot app examples to be smart and use the copy of those libraries in the u-boot image. For example the demo program in api_examples uses printf (65K library) instead of building an api calling into u-boot for printf.
HTH, gvb