The sparc openboot implementation can run executables in the a.out
format. We used to generate these using objcopy, but this does not work
anymore as binutils is deprecating a.out format support.
- Import elf2aout from FreeBSD
- Add some missing bits to our elf.h and have a copy of it in the build
headers so it can be used to build elf2aout for the host platform
(tested for Linux)
- Use it to generate the sparc haiku_loader
- Adjust the bootloader linker script to have two "program headers": one
that is not loadable and contains the ELF headers, and the second one
that is loadable and contains the actual code and data. Unlike
objcopy, elf2aout relies only on the program headers to know what to
put in its output file (sections are ignored), so this is required
otherwise we end up with the ELF header nested inside the a.out file,
and everything offset from the expected load address as a result.
Confirmed that this allows to build the loader and run it as far as
before, so I'm back to needing to implement some MMU support now.
FreeBSD commit: 7551d83c353e040b32c6ac205e577dbc5f2c8955
Change-Id: I90b48e578fa7f148aeddd8c5998fdddc5cfa73fa
Reviewed-on: https://review.haiku-os.org/c/1557
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
This was done using macros before, which isn't the way we have things set up.
In theory that method should work, however if not all consumers include the
libroot_build headers properly, then it breaks in subtle but confusing ways,
which is not what we want at all.
Thanks to Jessica for advice.
Change-Id: Idd45df5547daecf8239932957088da03ddfccf87
As it turns out, using the xattr emulation layer plus "libgnu"
causes some strange mixups at package build time, and so packages
built with it were winding up with no attributes at all.
So I've just bitten the bullet and written a full passthrough layer
to the system attributes. Verified using a full build of haiku.hpkg
this time ... after a lot of painful debugging of symlink mixups.
Hopefully I am finally rid of this plague...
To quote jscipione (from 95e8362c52),
"Let me tell you a story about a bug" -- though this tale spans a much
lesser time than that one did.
In 5e19679ea3, I enabled libroot_build for
Haiku, instead of using the system libroot as we had before. There were
a number of bugs introduced along with this that I hadn't fixed (and there
may be more after this), but most of the obvious ones (crashes on x86_64...)
were fixed shortly enough.
Attribute usage, though, was a different story. Unlike most of the POSIX
calls in libroot, which were aliasing system functions no matter what the
platform, the attribute calls were not, as they are specific to Haiku.
Initially I had completely forgot about them, and it wasn't until a few days
later when I noticed that I had an "attributes" directory in my generated
that I realized that the "generic" attribute layer was being used on Haiku.
I attempted a fix for this in 5e19679ea3,
thinking that would clear the problem up, but I didn't actually run a test
beyond seeing that my BuildConfig had been updated properly. In fact,
BuildSetup was hard-wired to not even pass that definition through on
Haiku, and so that commit had in effect caused nothing.
My initial "fix" of just changing BuildSetup then caused a build failure,
as while libroot_build itself compiled, it ran into errors whenever attributes
were used, because in letting the real libroot's attribute calls shine
through, I had bypassed libroot_build's FD emulation/shim layer.
Then I tried and failed at three separate attempts to solve this with code:
- a version of the "fs_attr_...h" interface for Haiku. This proved possible
in theory, but in practice I would need to reimplement a lot of attribute
handling code in it, because all I had access to from there was syscalls.
- a version of "fs_attr_untyped" that bypassed its reimplementations of
the "fs*attr" functions for the libroot ones, only using the FD shim layer.
This proved possibly not even theoretically possible because it would have
caused preprocessor hell in some of the build headers, and also assumptions
about how attributes are read were totally different.
- a completely new "fs_attr_haiku" that was a completely new interface to
the fs*attr functions. This proved practically impossible because of the
need to include structures from the system libroot to call out to readdir,
etc. that attempts to solve would also have caused preprocessor hell.
Then I realized that the Linux xattr emulation library, which I'd used
as a reference when attempting the first solution, was shipped by default
as a system library in all builds of Haiku ... and so I could just tell
fs_attr_untyped to use the Linux xattr handler, and then link against libgnu.
So that is how I arrived at this strange and decidedly unorthodox solution
to a problem of my own creation.
Now that we do not target BeOS and also do not include the main headers
directory when building "build" binaries, we can drop the separate
config_build directory and thus also the separate BeBuild.h, and just
..-include the regular one.
The build BeBuild.h defined empty _IMPEXP_ROOT and _IMPEXP_BE preprocessor
macros that the regular one does not; so I also re-synchronized
headers which used these as needed.
* libbe_build: Where possible we directly use the actual Haiku headers and
sources, now. In the headers/build headers we just include the respective
Haiku headers as needed. That still allows overrides where necessary. The
intention is to make it easier to keep the build stuff in sync.
* Fixed a few printf() format and signed/unsigned comparison warnings.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42179 a95241bf-73f2-0310-859d-f6bbb57e9c96
