HACK: Disable cache alignment warnings

They are very annoying and noisy
Add env vars describing U-Boot target board

This can be useful for generic scripts. For example, rather than hard-
coding a script to ext2load tegra-harmony.dtb, it could load
${soc}-${board}.dtb and hence not need adjustments to run on multiple
boards.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v3:
* Prefix config.h #defines with CONFIG_SYS_. The environment variable
  names remain unchanged.
v2:
* Pass values via config.h instead of command-line
* Use a single CONFIG option to enable this feature
* Simplify names of the environment variables
* add README entry describing CONFIG_ENV_VARS_UBOOT_CONFIG
tegra: enable CONFIG_ENV_VARS_UBOOT_CONFIG

So that all Tegra boards define environment variables that describe
themselves.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v2: Adjust to new CONFIG variable name
env_mmc: align buffers using ALLOC_CACHE_ALIGN_BUFFER

This allows MMC drivers to perform cache flusing on the bufffers
without issue.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Cc: Andy Fleming <afleming@gmail.com>
sf: winbond: Add support for the Winbond W25Q80BL

This chip is present on the Compulab TrimSlice.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
tegra: ventana: store environment in eMMC

Store the environment in eMMC, at the end of the second boot sector.
This should not conflict with any other eMMC usage: U-Boot is stored
well below this location, and the kernel only uses the general area
of the eMMC once booted, not the boot sectors.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
tegra: whistler: store environment in eMMC

Store the environment in eMMC, at the end of the second boot sector.
This should not conflict with any other eMMC usage: U-Boot is stored
well below this location, and the kernel only uses the general area
of the eMMC once booted, not the boot sectors.

Note: This assumes the user plugged the standard 8MB MoviNAND card into
J29/HSMMC/POP. If they didn't, the boot sector layout may be different.
However, use of that particular card is standard practice as far as I
know.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
tegra: trimslice: store environment in SPI flash

The chosen flash offset matches Compulab's downstream U-Boot.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
tegra: paz00: store environment in eMMC

Store the environment in eMMC, at the end of the second boot sector.
This should not conflict with any other eMMC usage: U-Boot is stored
well below this location, and the kernel only uses the general area
of the eMMC once booted, not the boot sectors.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
tegra: seaboard: disable SPI, move environment to eMMC

The SPI hardware on Seaboard is too broken to use; it is muxed with the
console UART and requires evil interactions between the SPI and UART
drivers to work even partially. The current code in U-Boot is not
sufficient to make this work correctly; auto boot is aborted due to
corruption in the UART RX channel interrupting it.

Instead, move the environment to eMMC, at the end of the second boot
sector. This should not conflict with any other eMMC usage, irrespective
of whether the board boots from SPI, NAND, or eMMC: if U-Boot is stored
in eMMC, it will be stored well below this location. The kernel only
uses the general area of the eMMC once booted, not the boot sectors.

Boards that are derivatives of Seaboard don't have the muxing issue,
and should/could have a separate U-Boot configuration file that does
enable SPI if desired.

Alternatively, the environment could be stored in NAND flash, but we
currently have no driver for that controller.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Cc: Simon Glass <sjg@chromium.org>