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From: Eric W B. <ebi...@ln...> - 2002-08-24 09:23:41
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ke...@us... (Ken Yap) writes: > >> Based on Ken's comments about needing to load the file in anyway, it occurs > >> to me that maybe you could integrate the checksum code with the code that > >> loads the file in. If you read in the file in 64K chunks, you could checksum > > >> each chunk. If you do this, benchmark it against the current version and > dump > > >> it if it isn't substantially faster (and maybe dump it anyway in the interest > > >> of readability if it only takes 0.1s). > > > >> It has been a long while since I looked at mknbi, so this idea might not > >> come anywhere close to useful. But since I had it, I thought I would > >> share it. :^) > > > >Always useful. And one of the points of a public discussion. > > Actually Don's suggestion is valid. If you look at mknbi, it copies the > data in 4kB chunks. So you could call the checksum routine for each > chunk, not have to do a substr because you know it's <= 4kB long, > and accumulate the checksum. Nice. > The trick will be how to insert the .note record. If it has to come > before the data, you may have to reserve the record in the output, > remember its offset, then come back and fill it in. If it comes after > the data, then there's no problem of course. If we only allow one note section, and spec it to contain arbitray data it should come before the rest of the image. This makes the implementation of the ELF loader simpler and reduces the restrictions on what we can do with the data. The other pieces of information I have notes for so far are the program name, and the program version. Which potentially makes code like if (freebsd) easier to write :) > Hopefully all this can be done in Elf.pm if I got the OO design right, > otherwise the interface may need to be tweaked a bit. When I get a chance to look I will see if I can answer this one. Eric |
