rk3399: Enable bootblock compression

This patch enables the new bootblock compression feature on RK3399,
which requires moving MMU initialization into the decompressor stage and
linking the decompressor (rather than the bootblock) into the entry
point jumped to by the masked ROM.

RK3399's masked ROM seems to be using a bitbang SPI driver to load us
(very long pauses between clocking in each byte), with an effective data
rate of about 1Mbit. Bootblock loading time (as measured on a SPI
analyzer) is reduced by almost 100ms (about a third), while the
decompression time is trivial (under 1ms).

Change-Id: I48967ca5bb51cc4481d69dbacb4ca3c6b96cccea
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/26341
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
7 files changed