with this, you can read 16KB and 128KB files, and output
them to stdout, but it outputs 8KB
for example:
./nvmutil gbe128.bin > gbe8.bin
now you have a 8KB file
i could probably easily add cat16 and cat128 too.
nvmutil reads two 4KB parts regardless of GbE file
size (one from the first 4KB of each half of the
file), so this was easy to implement.
Signed-off-by: Leah Rowe <leah@libreboot.org>
don't cast unsigned to signed.
no behaviour is changed, but this will prevent some
silly compilers complaining about -Wsign-conversion
Signed-off-by: Leah Rowe <leah@libreboot.org>
i removed this before, but it's good to put it
here defensively, in case i ever mess up
the urandom read function again.
Signed-off-by: Leah Rowe <leah@libreboot.org>
i forgot to handle it in the previous refactor
not really a problem in practise, since the first
read probably succeeds anyway.
Signed-off-by: Leah Rowe <leah@libreboot.org>
also handles possible overflows in read_gbe_file_exact
it removes dead code on both paths: arc4random and
urandom
Signed-off-by: Leah Rowe <leah@libreboot.org>
we rely on uint16_t wrapping, but some platforms may
behave weirdly.
cast as uint32_t and then cast back, on return, with
an explicit mask beforehand.
Signed-off-by: Leah Rowe <leah@libreboot.org>
i plan to release this as a standalone utility at
some point, once it's perfect (on its current
feature set)
Signed-off-by: Leah Rowe <leah@libreboot.org>
i will write a *manpage* at some point. for now, the
documentation on libreboot.org shall suffice.
i'm nearly ready to submit this code to coreboot.
Signed-off-by: Leah Rowe <leah@libreboot.org>
explicitly declare the directory path for the given
file (nvmutil), otherwise it's implementation-defined;
on some systems, /bin/nvmutil means a directory named
nvmutil could then contain nvmutil.
Signed-off-by: Leah Rowe <leah@libreboot.org>
I also needed: #define _POSIX_C_SOURCE 200809L
I use -pedantic with -Wall -Wextra -Werror, which
forces very strict error handling and ISO C; this
means pread and pwrite aren't available.
The define fixes this.
Signed-off-by: Leah Rowe <leah@libreboot.org>
only allow the long form: setmac [MAC]
specifying gbe.bin just shows the help/usage now.
this is a safety feature, so that someone doesn't
accidentally write the gbe file. we want it to be
that the user specifically requested setmac.
setmac with mac address as the 3rd argument is
also disabled. this is done as part of a general
simplification and safety improvement to nvmutil.
Signed-off-by: Leah Rowe <leah@libreboot.org>
this is an extremely dangerous feature, and serves
no purpose to the user.
this change is part of a series of extreme safety
improvements, part of a larger nvmutil audit.
Signed-off-by: Leah Rowe <leah@libreboot.org>
This feature is extremely dangerous, and we should
discourage against its use.
This is part of a series of changes that I've made
to make the code safer. You should only ever run
this on a valid GbE file, and nothing else.
Signed-off-by: Leah Rowe <leah@libreboot.org>
linear, top-down order. re-order the prototypes
also some general cleanup:
argc enums now validated. ifdefs for pledge
and arc4random now use a consistent naming
scheme.
feature change:
the "dump" command now fails if both checksums
are invalid, and won't show anything.
my next commit will disable setchecksum when
both checksums are invalid. this and the other
insane auditing i've done over the last few
days has been part of a major effort to make
nvmutil extremely safe, and robust.
Signed-off-by: Leah Rowe <leah@libreboot.org>
Leah Rowe