[PATCH v8 00/15] vpl: Introduce a verifying program loader

[Simon Glass]

U-Boot provides a verified-boot feature based around FIT, but there is
no standard way of implementing it for a board. At present the various
required pieces must be built up separately, to produce a working
implementation. In particular, there is no built-in support for selecting
A/B boot or recovery mode.

This series introduces VPL, a verified program loader phase for U-Boot.
Its purpose is to run the verified-boot process and decide which SPL
binary should be run. It is critical that this decision happens before
SPL runs, since SPL sets up SDRAM and we need to be able to update the
SDRAM-init code in the field.

Adding VPL into the boot flow provides a standard place to implement
verified boot. This series includes the phase itself, some useful Kconfig
options and a sandbox_vpl build for sandbox. No verfied-boot support is
provided in this series.

Most of the patches in this series are fixes and improvements to docs and
various Kconfig conditions for SPL.

This series requires the earlier sandbox fix patches[1] to be applied
first. A test is included to make sure that VPL runs correctly for
sandbox, i.e. that the TPL -> VPL -> SPL -> U-Boot flow works.

Future work will add an implementation of verified boot into VPL.

[1] https://patchwork.ozlabs.org/project/uboot/list/?series=297248

Changes in v8:
- Rename the VPL symbols in spl.c
- Support SYSCON and REGMAP too
- Update defconfig to account for option changes
- Drop reference to old OF_HOSTFILE option
- Add new patch to support running vpl tests

Changes in v7:
- Add a few more options
- Rebase to master
- Update some options based on settings in master

Changes in v6:
- Add docs for sandbox_vpl build
- Drop TPL_HASH_SUPPORT patch since we only have SPL_HASH now

Changes in v5:
- Rebase this patch on mainline (for GPIO and MISC Kconfig renames)

Changes in v4:
- Add new patch to correct bloblist Kconfig dependencies
- Add new patch to avoid building avb in SPL
- Update spl_phase_prefix() for VPL
- Tidy up some of the Makefile rules
- Add options for blk, core, misc and tpl also
- Add VPL_SIZE_LIMIT
- Add a sandbox_vpl build
- Update cover letter

Changes in v3:
- Move VPL Kconfig options to a separate patch
- Add full build support for VPL
- Add a VPL size check (Kconfig option in next patch)

Changes in v2:
- Add some more VPL Kconfig options

Simon Glass (15):
  test/py: Add a way to start sandbox without a device tree
  sandbox: Avoid binman error when run without device tree
  doc: Convert SPL documentation to ReST
  doc: Expand SPL docs to explain the phase and config
  test: Tidy up test building with SPL
  bloblist: Correct Kconfig dependencies
  avb: Don't build in SPL
  Makefile: Simplify devicetree rules for SPL/TPL
  Makefile: Tidy up the TPL build rules
  Introduce Verifying Program Loader (VPL)
  vpl: Add Kconfig options for VPL
  sandbox: Add a build for VPL
  vpl: Support running vpl tests
  vpl: Test that VPL runs correctly through to U-Boot proper
  CI: Run VPL tests

 .azure-pipelines.yml                |   3 +
 .gitlab-ci.yml                      |   6 +
 Kconfig                             |  10 ++
 Makefile                            |  28 +++-
 arch/sandbox/Kconfig                |   8 +
 arch/sandbox/cpu/cpu.c              |  27 ++-
 arch/sandbox/cpu/spl.c              |  12 +-
 arch/sandbox/dts/sandbox.dtsi       |  10 +-
 board/sandbox/MAINTAINERS           |   7 +
 common/Kconfig                      |  71 +++++++-
 common/Makefile                     |   2 +-
 common/spl/Kconfig                  | 234 +++++++++++++++++++++++++-
 common/spl/spl.c                    |  25 ++-
 configs/sandbox_vpl_defconfig       | 251 ++++++++++++++++++++++++++++
 doc/arch/sandbox.rst                |  13 ++
 doc/develop/index.rst               |   1 +
 doc/{README.SPL => develop/spl.rst} |  75 +++++++--
 drivers/Makefile                    |   2 +
 drivers/block/Kconfig               |  12 ++
 drivers/clk/Kconfig                 |  26 +++
 drivers/core/Kconfig                |  54 +++++-
 drivers/core/Makefile               |   2 +-
 drivers/gpio/Kconfig                |  11 ++
 drivers/i2c/Kconfig                 |  11 ++
 drivers/misc/Kconfig                |  28 ++++
 drivers/pinctrl/Kconfig             |  18 +-
 drivers/rtc/Kconfig                 |   9 +
 drivers/serial/Kconfig              |  20 +++
 drivers/sysreset/Kconfig            |  10 ++
 drivers/timer/Kconfig               |  10 ++
 drivers/tpm/Kconfig                 |  30 ++++
 dts/Kconfig                         |  17 ++
 include/bootstage.h                 |   2 +
 include/linux/kconfig.h             |   3 +
 include/spl.h                       |  22 ++-
 lib/Kconfig                         |  62 +++++++
 scripts/Kbuild.include              |   4 +
 scripts/Makefile.autoconf           |  12 ++
 scripts/Makefile.build              |   4 +
 scripts/Makefile.lib                |   5 +
 scripts/Makefile.spl                |  37 ++--
 test/py/conftest.py                 |   7 +-
 test/py/tests/test_help.py          |  26 +++
 test/py/tests/test_vpl.py           |  34 ++++
 test/py/u_boot_console_sandbox.py   |  22 ++-
 45 files changed, 1215 insertions(+), 68 deletions(-)
 create mode 100644 configs/sandbox_vpl_defconfig
 rename doc/{README.SPL => develop/spl.rst} (68%)
 create mode 100644 test/py/tests/test_vpl.py

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2.36.0.464.gb9c8b46e94-goog