On 08.02.2008 17:21, Chris Kilgour wrote: > Carl-Daniel Hailfinger wrote: > >>> Please be aware this is all completely untested; there could be plenty >>> of typos and plain-old mistakes inside. The binaries produced should be >>> considered unstable and experimental. Use them at your own risk! >>> >>> >>> >> I will try to take a look ASAP. The optimal case would be that the >> original and modified sources compile to an identical binary or at least >> a binary with perfectly explainable differences. >> >> >> > The VSA sources are a mix of assembly and C code. The binaries will be > quite different because (naturally) gcc will produce different machine > code than Microsoft C from the 16-bit era, and all the assembly-coded > functions are now using GNU __attribute__((fastcall)) rather than "MS > pascal" calling convention. Also, the final link output will have the > various bits and pieces in different locations. So a straight binary > diff will exhibit mostly differences. >
Understood. > That said, I took the time of locating and disassembling the assembly > functions from OLPC VSA blob and comparing against the output of the > assembly functions from my build (by far the biggest risk because of all > the manual modifications I made), and the differences were all > explainable in light of the above. For the C code I felt it was way too > hard to even attempt such an approach. > Thanks for investing the time to verify the differences. > Within the tarball there is a file modification_notes.txt that > highlights what I have done. I'm hoping to foster some discussion on a > testing approach that lays somewhere between manual inspection and > slapping the open-tools blob into a coreboot ROM and crossing our fingers... > I fear that for most of us the only way to test is to burn the generated VSA into a ROM and start the machine. However, I have to admit I didn't read the modification notes you supplied. I will read it. Regards, Carl-Daniel -- coreboot mailing list [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
