On Fri, Aug 20, 2021 at 12:22:22PM -0600, Simon Glass wrote: > Hi Francis, > > On Fri, 20 Aug 2021 at 10:12, Francis Laniel > <francis.lan...@amarulasolutions.com> wrote: > > > > Hi. > > > > > > I hope you are fine and the same for your family and friends. > > > > In July, a proposal to add a new shell for U-Boot was posted on the mailing > > list [1]. > > The community discussed a lot about this changes, some people did not agree > > with it because the new shell is not compatible with the actual one (hush) > > [2]. > > So, a proposal to update U-Boot actual hush to follow what they currently > > have > > in Busybox was made [3]. > > > > Porting 2021 Busybox hush to U-Boot seems, for me, to be a good idea as we > > would benefit from Busybox bug fixes as well as being compatible with actual > > hush (in theory). > > We could also add new features to U-Boot hush, like functions, as they were > > added to Busybox. > > > > Nonetheless, the idea of this port is to be compatible. > > In practice, I noted some cases when this is actually not the case. > > The first one can be related to how && and || operators were handled in > > hush. > > So, the following: false && false || true > > Returns 0 on Busybox 2021 hush and 1 on U-Boot. > > The behavior of 2021 is coherent with the definition of these operators [4]: > > > The return status of AND and OR lists is the exit > > > status of the last command executed in the list. > > An other example concerns variable expansion, where foo='bar "quux" is > > expanded to bar quux in U-Boot and bar "quux in Busybox. > > > > I do not have a real opinion on the second one, as I think local variable > > set > > in U-Boot scripts are quite simple as people do not try to do: foo="bar > > \"quux > > 'quuz' \"\"\"corge". > > The first one is maybe more problematic. > > Grepping "if test" shows me that the more complex if condition seems to be > > under the form: > > if first_test_ AND/OR second_test > > Here also, people seems to no try to write complex expression like: foo || > > bar; echo quux && quuz. > > > > So, porting Busybox 2021 hush can solve bugs we have currently in U-Boot, > > but > > what if fixing these bugs lead to a board script failing and so a device not > > booting... > > I would like to have the opinion of the community on this question. > > My feeling is that we should go with the newer (correct?) behaviour. > Boards not booting can be found with the existing release process. > > Also if we keep the old hush around for a while people can still use > it, particularly if it is much smaller.
I would at this point echo this sentiment as well. Thanks! -- Tom
signature.asc
Description: PGP signature
