OK, by now I'll keep using the alternative to use another name for the
elf app/FILE_APPS, as seemingly intended by
chao.an in his commit.
No, that was an error. The requirements have always supported
replacement of built-in applications with ELF applications. That is a
recommended way for updating an embedded system. The original PR broke
that logic.
I don't really understand Chaos solution because if the ELF app needs a
bigger stack, which is quite probable because it is a
derivation/evolution of the built-in command with the same name, you'll
have to increase the spawn stack size anyway !?!?
That is true. The assumption is that the stack size of the built-in
application will be big enough for the replacement ELF application.
That might not be true. But in the case of replacing a built-in
application with an ELF application, the rule is that we cannot modify
the base ROM logic. Imagine that I have 100,000 products in the field
and I want to replace a built-in. That is pretty easy to do by just
writing the ELF file to the some local file system. You would like to
avoid replacing the entire FLASH image.
And if it is not replacing an existing built-in application. Then there
is no information on stack size. The ELF format does have logic to
support a stack section, but that is not used by the loader. Other
formats do include the stack size as part of the header (NXFLAT, for
example). But otherwise, you have no option but to make the global
stack size larger for all applications.
We could potentially come up with an extended ELF head that includes
stack and priority information. I think it could be done because the
offsets in the ELF header permit the header to be extended. That would
be a good project.
But that's for you pros to decide.
I merged Xiang's change. Please try the changes in the repository now
if you can make the time (without changing the name of hello).
At least seems you got a communication problem here, because nobody had
a notion about the impact of Chaos commit.
Yes, a communication problem, a testing problem, a requirements problem,
many problems. You can help by contributing some time and effort to
make things better 8)
Greg
