The BCM2835 SoC contains (at least) two CPUs; the VideoCore (a/k/a "GPU")
and the ARM CPU. The ARM CPU is often thought of as the main CPU.
However, the VideoCore actually controls the initial SoC boot, and hides
much of the hardware behind a protocol. This protocol is transported
using the SoC's mailbox hardware module.
Here, we add a very simplistic driver for the mailbox module, and define
a few structures for the property messages.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
This SoC is used in the Raspberry Pi, for example.
For more details, see:
http://www.broadcom.com/products/BCM2835http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf.
Initial support is enough to boot to a serial console, execute a minimal
set of U-Boot commands, download data over a serial port, and boot a
Linux kernel. No storage or network drivers are implemented.
GPIO driver originally by Vikram Narayanan <vikram186@gmail.com>
with many fixes from myself.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
