On Tegra186, U-Boot is booted by the binary firmware as if it were a
Linux kernel. Consequently, a DTB is passed to U-Boot. Cache the address
of that DTB, and parse the /memory/reg property to determine the actual
RAM regions that U-Boot and subsequent EL2/EL1 SW may actually use.
Given the binary FW passes a DTB to U-Boot, I anticipate the suggestion
that U-Boot use that DTB as its control DTB. I don't believe that would
work well, so I do not plan to put any effort into this. By default the
FW-supplied DTB is the L4T kernel's DTB, which uses non-upstreamed DT
bindings. U-Boot aims to use only upstreamed DT bindings, or as close as
it can get. Replacing this DTB with a DTB using upstream bindings is
physically quite easy; simply replace the content of one of the GPT
partitions on the eMMC. However, the binary FW at least partially relies
on the existence/content of some nodes in the DTB, and that requires the
DTB to be written according to downstream bindings. Equally, if U-Boot
continues to use appended DTBs built from its own source tree, as it does
for all other Tegra platforms, development and deployment is much easier.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Many files in arch/arm/mach-tegra are compiled conditionally based on
Kconfig variables, or applicable to all platforms. We can let the main
Tegra Makefile handle compiling (or not) those files to avoid each SoC-
specific Makefile needing to duplicate entries for those files. This
leaves the SoC-specific Makefiles to compile truly SoC-specific code.
In the future, we'll hopefully add Kconfig variables for all the other
files, and refactor those files, and so reduce the need for SoC-specific
Makefiles and/or ifdefs in the Makefiles.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This adds the bare minimum code to support Tegra186, with UART and eMMC
working.
The empty gpio.h is required because <asm/gpio.h> includes it. A future
cleanup round may be able to solve this for all Tegra generations at once.
mach-tegra/Makefile is adjusted not to compile anything for Tegra186, but
instead to defer everything to mach-tegra/tegra186/Makefile. This allows
the SoC code to pick-and-choose which of the C files in the "common"
mach-tegra/ directory to compile in based on the SoC's needs. Most of the
code is not valid for Tegra186, and this approach removes the need for
mach-tegra/Makefile to contain many SoC-specific ifdefs. This approach
may be applied to all other Tegra SoCs in a future cleanup round.
board186.c is introduced to replace board.c and board2.c. These files
currently contain a slew of SoC- and board-specific code that is not
valid for Tegra186. This approach avoids adding yet more ifdefs to those
files. A future cleanup round may refactor most of board*.c into board-/
SoC-specific functions files thus allowing the top-level functions like
board_init_early_f to be shared again.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
