Le 11/04/2011 20:52, Andreas Pretzsch a écrit : > Objective: Skip an area in memory commands > > Example use case: Skip over embedded environment when updating U-Boot > > In case of an embedded environment, a complete U-Boot binary consists of > two code sections and an environment block in between. In an update flow > tftp/erase/cp/cmp conveniently using the complete image, the environment > is also overwritten. As the env might contain device specific data, this > is not always desirable. > Of course, one could overcome this with several approaches, e.g. > - provide two distinct U-Boot parts on the tftp server > - load the complete image and erase/cp/cmp only the desired parts, > either via hardcoded addresses and sizes or via some setexpr magic > - other ways I simply missed > > While this is sufficent, I'd find it handy to be able to skip an area in > the above commands. > Possible approaches: > - explicit via additional parameters to cp, cmp, etc. > - implicit for the embedded environment (confusing and less generic) > - based on e.g. some skip_addr, skip_len environment variables or > even sets (addr1,addr2 + len1,len2) > > There might be other use cases I didn't thought of by now. Also, the > command list is probably not complete. > > What do you think, worth the effort, acceptable in mainline or > over-engineering ?
Over-engineering IMO. There is a reason why a board defines its environment as embedded, and it is because it wants it applied when flashing a new U-Boot. But if you really want to keep the existing embedded environment when flashing a new U-Boot, then after you have loaded the new U-Boot in RAM as usual, all you need is to overwrite its environment with the one already in Flash with a single, standard, cp.b instruction. After that you can erase Flash and copy from RAM to Flash as usual. Amicalement, -- Albert. _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
