The attached patch enables u-boot for puma-rk3399. It enables a build of
the vendor's arm-trusted-firmware/rk3399-cortex-m0, and the installation
offsets to install the u-boot to microSD.

Tested running on a puma-rk3399-haikou board running GuixSD!

There is one glitch, which is that the fdtfile variable in u-boot
(rockchip/rk3399-puma-ddr1600.dtb) does not match the device-tree
present in linux-libre (rockchip/rk3399-puma-haikou.dtb), so the fdtfile
u-boot variable needs to manually be set at boot to match
linux-libre. This is likely to be fixed in future u-boot versions.

Vagrant Cascadian (1):
  system: Add u-boot-puma-rk3399.

 gnu/bootloader/u-boot.scm    | 16 +++++++++++
 gnu/packages/bootloaders.scm | 36 ++++++++++++++++++++++++-
 gnu/packages/firmware.scm    | 64 ++++++++++++++++++++++++++++++++++++++++++++
 gnu/system/install.scm       |  6 +++++
 4 files changed, 121 insertions(+), 1 deletion(-)

-- 
2.11.0