| 6f9d9986 | 05-Dec-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Add support for specifying an initrd with the zboot command
This change finishes plumbing the initrd support built into the zboot
mechanism out to the command interface.
It also fixes a bug in
x86: Add support for specifying an initrd with the zboot command
This change finishes plumbing the initrd support built into the zboot
mechanism out to the command interface.
It also fixes a bug in the command declaration where the kernel size could
be passed as an optional second parameter but not enough arguments were
allowed.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| 69370d14 | 05-Dec-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Refactor the zboot innards so they can be reused with a vboot image
If vboot successfully verifies a kernel, it will leave it in place and
basically ready to boot. The zeropage table which is p
x86: Refactor the zboot innards so they can be reused with a vboot image
If vboot successfully verifies a kernel, it will leave it in place and
basically ready to boot. The zeropage table which is part of the x86 boot
protocol is at the end of the kernel, though, instead of the beginning, and
because the image is already in place there's no need to copy it around.
This change refactors the code which implements the zboot command so that
the configuration of the zeropage table and loading the pieces of the
kernel into memory are done separately. Also, because the command line goes
before the zeropage table in vboot which is somewhat incompatible with the
normal protocol, where to put the command line is a now a parameter instead
of being hard coded.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| 233dbc11 | 05-Dec-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Add support for booting Linux using the 32 bit boot protocol
This change conditionally modifies the zboot command so that it can use the
32 bit boot protocol. This is necessary because the 16 b
x86: Add support for booting Linux using the 32 bit boot protocol
This change conditionally modifies the zboot command so that it can use the
32 bit boot protocol. This is necessary because the 16 bit realmode entry
point assumes that it can call BIOS services which neither coreboot nor
u-boot provide.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| 36b2409a | 16-Nov-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Wrap small helper functions from libgcc to avoid an ABI mismatch
When gcc compiles some 64 bit operations on a 32 bit machine, it generates
calls to small functions instead of instructions whic
x86: Wrap small helper functions from libgcc to avoid an ABI mismatch
When gcc compiles some 64 bit operations on a 32 bit machine, it generates
calls to small functions instead of instructions which do the job directly.
Those functions are defined in libgcc and transparently provide whatever
functionality was necessary. Unfortunately, u-boot can be built with a
non-standard ABI when libgcc isn't. More specifically, u-boot uses
-mregparm. When the u-boot and libgcc are linked together, very confusing
bugs can crop up, for instance seemingly normal integer division or modulus
getting the wrong answer or even raising a spurious divide by zero
exception.
This change borrows (steals) a technique and some code from coreboot which
solves this problem by creating wrappers which translate the calling
convention when calling the functions in libgcc. Unfortunately that means
that these instructions which had already been turned into functions have
even more overhead, but more importantly it makes them work properly.
To find all of the functions that needed wrapping, u-boot was compiled
without linking in libgcc. All the symbols the linker complained were
undefined were presumed to be the symbols that are needed from libgcc.
These were a subset of the symbols covered by the coreboot code, so it was
used unmodified.
To prevent symbols which are provided by libgcc but not currently wrapped
(or even known about) from being silently linked against by code generated
by libgcc, a new copy of libgcc is created where all the symbols are
prefixed with __normal_. Without being purposefully wrapped, these symbols
will cause linker errors instead of silently introducing very subtle,
confusing bugs.
Another approach would be to whitelist symbols from libgcc and strip out
all the others. The problem with this approach is that it requires the
white listed symbols to be specified three times, once for objcopy, once so
the linker inserts the wrapped, and once to generate the wrapper itself,
while this implementation needs it to be listed only twice. There isn't
much tangible difference in what each approach produces, so this one was
preferred.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| dbaef6ef | 14-Nov-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Import the glibc memset implementation
The new implementation is about twice as fast as the old. This is from
glibc-2.14, sysdeps/i386/memset.c.
Signed-off-by: Gabe Black <gabeblack@chromium.o
x86: Import the glibc memset implementation
The new implementation is about twice as fast as the old. This is from
glibc-2.14, sysdeps/i386/memset.c.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| 769db03a | 12-Nov-2011 |
Gabe Black <gabeblack@chromium.org> |
x86: Don't relocate symbols which point to things that aren't relocated
This change adds an upper bound for symbols which are fixed up after u-boot
is relocated into RAM. This way portions that are
x86: Don't relocate symbols which point to things that aren't relocated
This change adds an upper bound for symbols which are fixed up after u-boot
is relocated into RAM. This way portions that are left at their original
location can be referred to without having to manually fix up any pointers.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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| 03228b26 | 12-Nov-2011 |
Gabe Black <gabeblack@google.com> |
x86: Fix how the location of the realmode and bios blobs are calculated
There are two blobs embedded into the u-boot image which are linked to run
at an address which is different from where they ac
x86: Fix how the location of the realmode and bios blobs are calculated
There are two blobs embedded into the u-boot image which are linked to run
at an address which is different from where they actually end up in the
ROM, one called "realmode" and one called "bios". There are realmode_setup
and bios_setup functions which prepare those blobs by copying them into the
location they're supposed to run from, among other things.
During u-boot relocation from ROM to RAM, the text and a few data segments
are copied over. The realmode and bios sections are not copied, and so the
only place they can be read from is their original location in the ROM.
Looking specifically at the bios blob, there are symbols defined in the
linker script called __bios_start and __bios_size which are defined to be
the start and size of the blob in the ROM.
In the bios_setup function, there seem to be two mistakes happening. First,
the offset from ROM to RAM is being added to __bios_start which implies that
this code expects to use the copy moved to RAM. No such copy is made, so
that's wrong. More subtly, when u-boot relocates itself, it goes through
all of the relocations stored in .rel.dyn and fixes them up. This has the
effect of transforming the __bios_start reference in bios_setup so that it
refers to the version in RAM (if one existed) instead of the one in ROM. To
correct for that, the offset actually needs to be subtracted out again to
translate the address back into the ROM.
The net effect is that for both blobs, a + needs to be changed to a -.
Signed-off-by: Gabe Black <gabeblack@chromium.org>
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