Raspberry Pi 4 project definition, Mini UART driver

Basic declaration of rpi4 target. Include in main build target for
the reference project (tests other than 'arch' not compiled yet).

Add driver for Mini UART, the main console of Raspberry Pi.

Bug: 140223574
Change-Id: I0450d3076656d81d7376fc168c51f0876af067cf
5 files changed
tree: 3dc50151cf987ce70dd664e59f135740a70b4c96
  1. aem_v8a_fvp/
  2. hikey/
  3. qemu_aarch64/
  4. rpi/
  5. rpi4/
  6. AUTHORS
  7. BUILD.gn
  8. LICENSE