[U-Boot] [PATCH v4 0/4] x86: Add support for booting from TPL

[Simon Glass]

At present SPL is used on 64-bit platforms, to allow SPL to be built as
a 32-bit program and U-Boot proper to be built as 64-bit.

However it is useful to be able to use SPL on any x86 platform, where
U-Boot needs to be updated in the field. Then SPL can select which U-Boot
to run (A or B) and most of the code can be updated. Similarly, using TPL
allows both SPL and U-Boot to be updated. This is the best approach, since
it means that all of U-Boot proper as well as SPL (in particular SDRAM
init) can be updated in the field. This provides for the smallest possible
amount of read-only (non-updateable) code: just the TPL code.

This series contains a number of changes to allow x86 boards to use TPL,
SPL and U-Boot proper. As a test, it is enabled for samus with a new
chromebook_samus_tpl board.

Changes in v4:
- Update commit message to not mention the sysreset driver.
- Drop change to SPI flash memory-map property

Changes in v3:
- Remove unneeded pch-reset node

Changes in v2:
- Sort defconfig and adjust it to build after rebase on maste

Simon Glass (4):
  x86: samus: Update device tree for SPL
  x86: samus: Update device tree for verified boot
  Revert "pci: Scale MAX_PCI_REGIONS based on CONFIG_NR_DRAM_BANKS"
  x86: samus: Add a target to boot through TPL

 arch/x86/dts/chromebook_samus.dts         | 53 +++++++++++++--
 board/google/Kconfig                      |  8 +++
 board/google/chromebook_samus/Kconfig     | 14 +++-
 board/google/chromebook_samus/MAINTAINERS |  7 ++
 configs/chromebook_samus_tpl_defconfig    | 82 +++++++++++++++++++++++
 include/configs/chromebook_samus.h        |  2 +
 include/pci.h                             |  6 +-
 7 files changed, 161 insertions(+), 11 deletions(-)
 create mode 100644 configs/chromebook_samus_tpl_defconfig

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