97542110f0
This patch makes some slight changes to the exception hook interface. The old code provides a different handler hook for every exception type... however, in practice all those hook functions often need to look very similar, so this creates more boilerplate than it removes. The new interface just allows for a single hook with the exception type passed as an argument, and the consumer can signal whether the exception was handled through the return value. (Right now this still only supports one consumer, but it could easily be extended to walk through a list of hooks if the need arises.) Also move the excepton state from an argument to a global. This avoids a lot of boilerplate since some consumers need to change the state from many places, so they would have to pass the same pointer around many times. It also removes the false suggestion that the exception state was not global and you could have multiple copies of it (which the exception core doesn't support for any architecture). On the ARM side, the exception state is separated from the exception stack for easier access. (This requires some assembly changes, and I threw in a few comments and corrected the immediate sigils from '$' to the official '#' while I'm there.) Since the exception state is now both stored and loaded through an indirection pointer, this allows for some very limited reentrance (you could point it to a different struct while handling an exception, and while you still won't be able to return to the outer-level exception from there, you could at least swap out the pointer and return back to System Mode in one go). BUG=chrome-os-partner:18390 TEST=Made sure normal exceptions still get dumped correctly on both archs. Change-Id: I5d9a934fab7c14ccb2c9d7ee4b3465c825521fa2 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/202562 Reviewed-by: Stefan Reinauer <reinauer@chromium.org> |
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|---|---|---|
| .. | ||
| arch | ||
| bin | ||
| configs | ||
| crypto | ||
| curses | ||
| drivers | ||
| include | ||
| libc | ||
| libcbfs | ||
| liblzma | ||
| libpci | ||
| sample | ||
| tests | ||
| util | ||
| Config.in | ||
| Doxyfile | ||
| LICENSES | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------
libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().
Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See http://coreboot.org for details on coreboot.
Installation
------------
$ git clone http://review.coreboot.org/p/coreboot.git
$ cd coreboot/payloads/libpayload
$ make menuconfig
$ make
$ sudo make install (optional, will install into /opt per default)
As libpayload is for 32bit x86 systems only, you might have to install the
32bit libgcc version, otherwise your payloads will fail to compile.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.
Usage
-----
Here's an example of a very simple payload (hello.c) and how to build it:
#include <libpayload.h>
int main(void)
{
printf("Hello, world!\n");
return 0;
}
Building the payload using the 'lpgcc' compiler wrapper:
$ lpgcc -o hello.elf hello.c
Please see the sample/ directory for details.
Website and Mailing List
------------------------
The main website is http://www.coreboot.org/Libpayload.
For additional information, patches, and discussions, please join the
coreboot mailing list at http://coreboot.org/Mailinglist, where most
libpayload developers are subscribed.
Copyright and License
---------------------
See LICENSES.