Ronald G Minnich a92a07d9c0 libpayload: allow nonblocking delay and more than one delay
Extend the local APIC timer delay so that it can be started,
and waited for, independently.

Add an EOI so that more than one APIC timer interrupt is possible.
Previous to this, because there was no EOI, the first timer
interrupt the CPU took was also the last it would take --
apic_delay would only work one time.

Change-Id: Ib11aeee5b7da81287166ac68fc327e7ae62d1b84
Signed-off-by: Ronald G Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43323
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
2020-07-16 16:48:42 +00:00
..
2020-03-02 15:03:03 +00:00
2015-06-08 00:55:07 +02:00

-------------------------------------------------------------------------------
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 https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


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 https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.