mbox series

[Concept,00/18] ulib: Introduce building U-Boot as a shared library

Message ID 20250904130459.848794-1-sjg@u-boot.org
Headers
Series ulib: Introduce building U-Boot as a shared library |

Message

Simon Glass Sept. 4, 2025, 1:04 p.m. UTC 
  From: Simon Glass <sjg@chromium.org>

U-Boot is currently built as a monolithic binary. While there is an API
of sorts, allowing U-Boot to be called from another program, it is not
widely used.

In some cases it is useful to write a separate program which is in
control of the boot process, but uses U-Boot to implement some of the
functionality.

Some examples are:
- Creating a main program written in a different language, such as Rust
  or Python
- For Python specifically, an interface on top of U-Boot would permit
  direct execution of sandbox tests
- For Rust specifically, it could make it feasible to progressively
  rewrite U-Boot in Rust, if that were desirable
- For testing, it would permit tests to be in control of execution,
  rather than being embedded within U-Boot itself

This series begins the progress of supporting U-Boot as a shared
library. At this point the functionality is very limited:

- it targets sandbox only
- the test program simply starts U-Boot and boots to a prompt

Future work will build on this meagre foundation.


Simon Glass (18):
  doc: Add fuzzing build documentation
  board_r: Drop MMC init from the startup sequence
  sandbox: Avoid mon_len being larger than available RAM
  sandbox: Move PCI functions to separate header file
  sandbox: Move main.h contents into u-boot-sandbox header
  sandbox: Split main() into separate file
  sandbox: Extract init code into sandbox_init()
  ulib: Add an option to build U-Boot as a library
  ulib: Support building U-Boot as a shared library
  ulib: Create a test program for the shared library
  ulib: Add linker script for shared library build
  ulib: efi: Disable relocation or runtime-services
  ulib: Enable building the ulib test program
  ulib: Implement GD_FLG_ULIB for library-usage mode
  ulib: Drop the initial banner for the library
  ulib: Drop DRAM announcements for the library
  ulib: Allow dropping NAND init from the startup sequence
  ulib: Drop dm stats for the library

 Kconfig                                   |   9 +
 Makefile                                  |  31 ++-
 arch/sandbox/cpu/Makefile                 |   7 +-
 arch/sandbox/cpu/fuzz.c                   |  81 ++++++++
 arch/sandbox/cpu/main.c                   |  11 ++
 arch/sandbox/cpu/mem.c                    |   1 +
 arch/sandbox/cpu/os.c                     |  76 +-------
 arch/sandbox/cpu/start.c                  |  26 ++-
 arch/sandbox/cpu/u-boot-lib.lds           |  88 +++++++++
 arch/sandbox/include/asm/main.h           |  18 --
 arch/sandbox/include/asm/sandbox_pci.h    |  61 ++++++
 arch/sandbox/include/asm/u-boot-sandbox.h |  76 ++++----
 common/board_f.c                          |  24 ++-
 common/board_r.c                          |  17 +-
 configs/tools-only_defconfig              |   1 +
 doc/build/fuzz.rst                        | 219 ++++++++++++++++++++++
 doc/build/index.rst                       |   1 +
 drivers/pci/pci-emul-uclass.c             |   3 +-
 include/asm-generic/global_data.h         |  12 ++
 lib/display_options.c                     |  15 +-
 lib/efi_loader/efi_runtime.c              |   4 +
 test/dm/pci.c                             |   1 +
 test/ulib/Makefile                        |  12 ++
 test/ulib/ulib_test.c                     |  37 ++++
 24 files changed, 658 insertions(+), 173 deletions(-)
 create mode 100644 arch/sandbox/cpu/fuzz.c
 create mode 100644 arch/sandbox/cpu/main.c
 create mode 100644 arch/sandbox/cpu/u-boot-lib.lds
 delete mode 100644 arch/sandbox/include/asm/main.h
 create mode 100644 arch/sandbox/include/asm/sandbox_pci.h
 create mode 100644 doc/build/fuzz.rst
 create mode 100644 test/ulib/Makefile
 create mode 100644 test/ulib/ulib_test.c