Hi!
During 2021 summer, Sean Anderson wrote a contribution to add a new shell, based on LIL, to U-Boot [1, 2]. While one of the goals of this contribution was to address the fact actual U-Boot shell, which is based on Busybox hush, is old there was a discussion about adding a new shell versus updating the actual one [3, 4].
So, in this series, with Harald Seiler, we updated the actual U-Boot shell to reflect what is currently in Busybox source code. Basically, this contribution is about taking a snapshot of Busybox shell/hush.c file (as it exists in commit 37460f5da) and adapt it to suit U-Boot needs.
This contribution was written to be as backward-compatible as possible to avoid breaking the existing. So, the modern hush flavor offers the same as the actual, that is to say: 1. Variable expansion. 2. Instruction lists (;, && and ||). 3. If, then and else. 4. Loops (for, while and until). No new features offered by Busybox hush were implemented (e.g. functions).
It is possible to change the parser at runtime using the "cli" command: => cli print old => cli set modern => cli print modern => cli set old The default parser is the old one. Note that to use both parser, you would need to set both CONFIG_HUSH_MODERN_PARSER and CONFIG_HUSH_OLD_PARSER.
In terms of testing, new unit tests were added to ut to ensure the new behavior is the same as the old one and it does not add regression. Nonetheless, if old behavior was buggy and fixed upstream, the fix is then added to U-Boot [5]. In sandbox, all of these tests pass smoothly: => printenv board board=sandbox => ut hush Running 20 hush tests ... Failures: 0 => cli set modern => ut hush Running 20 hush tests ... Failures: 0
Thanks to the effort of Harald Seiler, I was successful booting a board: => printenv fdtfile fdtfile=amlogic/meson-gxl-s905x-libretech-cc.dtb => cli get old => boot ... root@lepotato:~# root@lepotato:~# reboot ... => cli set modern => cli get modern => printenv fdtfile fdtfile=amlogic/meson-gxl-s905x-libretech-cc.dtb => boot ... root@lepotato:~#
This contribution indeed adds a lot of code and there were concern about its size [6, 7]. With regard to the amount of code added, the cli_hush_upstream.c is 13030 lines long but it seems a smaller subset is really used: gcc -D__U_BOOT__ -E common/cli_hush_upstream.c | wc -l 2870 Despite this, it is better to still have the whole upstream code for the sake of easing maintenance. With regard to memory size, I conducted some experiments for version 8 of this series and for a subset of arm64 boards and found the worst case to be 4K [8]. Tom Rini conducted more research on this and also found the increase to be acceptable [9].
If you want to review it - your review will really be appreciated - here are some information regarding the commits: * commits marked as "test:" deal with unit tests. * commit "cli: Add Busybox upstream hush.c file." copies Busybox shell/hush.c into U-Boot tree, this explain why this commit contains around 12000 additions. * commit "cli: Port Busybox 2021 hush to U-Boot." modifies previously added file to permit us to use this as new shell. The really good idea of #include'ing Busybox code into a wrapper file to define some particular functions while minimizing modifications to upstream code comes from Harald Seiler. * commit "cmd: Add new parser command" adds a new command which permits selecting parser at runtime. I am not really satisfied with the fact it calls cli_init() and cli_loop() each time the parser is set, so your reviews would be welcomed. * Other commits focus on enabling features we need (e.g. if).
Changes since: v2: * Added a small fix to compile sandbox with NO_SDL=1. * Added a command to change parser at runtime. * Added 2021 parser function to all run_command*(). v3: * Various bug fixes pointed by the CI. * Added upstream busybox hush commits until 6th February 2022. v4: * Various cleaning. * Modified python test to accept failure output when the test are designed to fail. * Bumped upstream busybox hush commits until 24h March 2022. v5: * Bumped upstream busybox hush commits until 30th January 2023. * Fix how hush interprets '<' and '>', indeed we needed to escape them but I removed this behavior as tests are handled by test command and not hush itself. This permitted to have the ut fdt to pass. * Fix a problem with how exit was handled. This was reported by the ut exit test. v6: * There was no v6 and I got mixed up with version. v7: * Bumped upstream busybox hush commits until 9th May 2023. * Renamed parser command to change parser at runtime to cli and added documentation. * Added better separation of patches. * Removed code about __gnu_thumb1_case_si as it was merged in another series. * Various cleaning. v8: * Bumped upstream busybox hush commits until 25th May 2023. v9: * Bumped upstream busybox hush commits until 2nd October 2023. v10: * Fixed a build error in commit adding cli command. * Add new CONFIG_HUSH_SELECTABLE to only build cli command if the two shell flavors are selected. v11: * Renamed everything containing 2021 to modern. * Fixed cmd Kconfig indentation. * Set modern parser as default for majority of boards except some. v12: * Rebased on top of 36d3db6c2c06. * Fixed bootflow_scan_menu_boot for modern hush.
Francis Laniel (24): test: Add framework to test hush behavior test: hush: Test hush if/else test/py: hush_if_test: Remove the test file test: hush: Test hush variable expansion test: hush: Test hush commands list test: hush: Test hush loops cli: Add Busybox upstream hush.c file cli: Port upstream Busybox hush to U-Boot cli: Add menu for hush parser global_data.h: add GD_FLG_HUSH_OLD_PARSER flag cmd: Add new cli command cli: Enables using modern hush parser as command line parser cli: hush_modern: Enable variables expansion for modern hush cli: hush_modern: Add functions to be called from run_command() cli: add modern hush as parser for run_command*() test: hush: Fix instructions list tests for modern hush test: hush: Fix variable expansion tests for modern hush cli: hush_modern: Enable using < and > as string compare operators cli: hush_modern: Enable if keyword cli: hush_modern: Enable loops test: hush: Fix loop tests for modern hush cli: modern_hush: Add upstream commits up to 2nd October 2023. cmd: Set modern hush as default shell configs: Use old hush for several boards
cmd/Kconfig | 21 + cmd/Makefile | 2 + cmd/cli.c | 134 + common/Makefile | 3 +- common/cli.c | 82 +- common/cli_hush_modern.c | 324 + common/cli_hush_upstream.c | 13030 +++++++++++++++++++++++ configs/kmcent2_defconfig | 1 + configs/kmcoge5ne_defconfig | 1 + configs/kmeter1_defconfig | 1 + configs/kmopti2_defconfig | 1 + configs/kmsupx5_defconfig | 1 + configs/kmtepr2_defconfig | 1 + configs/pg_wcom_expu1_defconfig | 1 + configs/pg_wcom_expu1_update_defconfig | 1 + configs/pg_wcom_seli8_defconfig | 1 + configs/pg_wcom_seli8_update_defconfig | 1 + configs/socfpga_secu1_defconfig | 1 + configs/tuge1_defconfig | 1 + configs/tuxx1_defconfig | 1 + doc/usage/cmd/cli.rst | 74 + doc/usage/index.rst | 1 + include/asm-generic/global_data.h | 8 + include/cli_hush.h | 51 +- include/test/hush.h | 15 + include/test/suites.h | 1 + test/Makefile | 3 + test/boot/bootflow.c | 16 +- test/cmd_ut.c | 6 + test/hush/Makefile | 10 + test/hush/cmd_ut_hush.c | 20 + test/hush/dollar.c | 226 + test/hush/if.c | 316 + test/hush/list.c | 140 + test/hush/loop.c | 91 + test/py/tests/test_hush_if_test.py | 197 - test/py/tests/test_ut.py | 8 +- 37 files changed, 14580 insertions(+), 212 deletions(-) create mode 100644 cmd/cli.c create mode 100644 common/cli_hush_modern.c create mode 100644 common/cli_hush_upstream.c create mode 100644 doc/usage/cmd/cli.rst create mode 100644 include/test/hush.h create mode 100644 test/hush/Makefile create mode 100644 test/hush/cmd_ut_hush.c create mode 100644 test/hush/dollar.c create mode 100644 test/hush/if.c create mode 100644 test/hush/list.c create mode 100644 test/hush/loop.c delete mode 100644 test/py/tests/test_hush_if_test.py
Have a nice end of the year and thank you in advance! --- [1] https://lists.denx.de/pipermail/u-boot/2021-July/453347.html [2] https://runtimeterror.com/tech/lil/ [3] https://lists.denx.de/pipermail/u-boot/2021-July/453790.html [4] https://lists.denx.de/pipermail/u-boot/2021-July/453848.html [5] https://lists.denx.de/pipermail/u-boot/2021-August/458569.html [6] https://lists.denx.de/pipermail/u-boot/2023-November/536768.html [7] https://lists.denx.de/pipermail/u-boot/2023-May/518140.html [8] https://lists.denx.de/pipermail/u-boot/2023-May/518147.html [9] https://lists.denx.de/pipermail/u-boot/2023-November/536952.html -- 2.34.1