This series creates a generic board.c implementation which contains the essential functions of the major arch/xxx/lib/board.c files.
What is the motivation for this change?
1. There is a lot of repeated code in the board.c files. Any change to things like setting up the baud rate requires a change in 10 separate places.
2. Since there are 10 separate files, adding a new feature which requires initialisation is painful since it must be independently added in 10 places.
3. As time goes by the architectures naturely diverge since there is limited pressure to compare features or even CONFIG options against simiilar things in other board.c files.
4. New architectures must implement all the features all over again, and sometimes in subtley different ways. This places an unfair burden on getting a new architecture fully functional and running with U-Boot.
5. While it is a bit of a tricky change, I believe it is worthwhile and achievable. There is no requirement that all code be common, only that the code that is common should be located in common/board.c rather than arch/xxx/lib/board.c.
All the functions of board_init_f() and board_init_r() are broken into separate function calls so that they can easily be included or excluded for a particular architecture. It also makes it easier to adopt Graeme's initcall proposal when it is ready.
http://lists.denx.de/pipermail/u-boot/2012-January/114499.html
This series removes the dependency on generic relocation. So relocation happens as one big chunk and is still completely arch-specific. See the relocation series for a proposed solution to this for ARM:
http://lists.denx.de/pipermail/u-boot/2011-December/112928.html
or Graeme's recent x86 series v2:
http://lists.denx.de/pipermail/u-boot/2012-January/114467.html
Instead of moving over a whole architecture, this series takes the approach of simply enabling generic board support for an architecture. It is then up to each board to opt in by defining CONFIG_SYS_GENERIC_BOARD in the board config file. If this is not done, then the code will be generated as before. This allows both sets of code to co-exist until we are comfortable with the generic approach, and enough boards run.
ARM is a relatively large board.c file and one which I can test, therefore I think it is a good target for this series. On the other hand, x86 is relatively small and simple, but different enough that it introduces a few issues to be solved. So I have chosen both ARM and x86 for this series. After a suggestion from Wolfgang I have added PPC also. This is the largest and most feature-full board, so hopefully we have all bases covered in this RFC.
A generic global_data structure is also required. This might upset a few people. Here is my basic reasoning: most fields are the same, all architectures include and need it, most global_data.h files already have #ifdefs to select fields for a particular SOC, so it is hard to see why architecures are different in this area. We can perhaps add a way to put architecture-specific fields into a separate header file, but for now I have judged that to be counter-productive.
Similarly we need a generic bd_info structure, since generic code will be accessing it. I have done this in the same way as global_data and the same comments apply.
There was dicussion on the list about passing gd_t around as a parameter to pre-relocation init functions. I think this makes sense, but it can be done as a separate change, and this series does not require it.
While this series needs to stand on its own (as with the link script cleanup series and the generic relocation series) the goal is the unification of the board init code. So I hope we can address issues with this in mind, rather than focusing too narrowly on particular ARM, x86 or PPC issues.
I have run-tested ARM on Tegra Seaboard only. To try it out, define CONFIG_SYS_GENERIC_BOARD in your board file and rebuild. Most likely on x86 and PPC at least it will hang, but if you are lucky it will print something first :-)
I have run this though MAKEALL with CONFIG_SYS_GENERIC_BOARD on for all ARM, PPC and x86 boards. There are a few failures, some due to errors in the board config, some due to things that need fixing. I will address these with the final series if required.
Note: the first group of commits are required for this series to build, but could be separated out if required. I have included them here for convenience.
Comments welcome.
Changes in v2: - Change generic board to an opt-in system on a per-board basic - Add CONFIG_SYS_GENERIC_BOARD to allow board to select generic board - Add PowerPC support - Rebase to master
Simon Glass (28): arm: Change board baud_rate to ulong x86: Change board baud_rate to ulong arm: Only display frame buffer info if there is LCD/video support x86: Remove compiler warning in sc520_timer.c x86: Remove dead code in eNET x86: Add initial memory barrier macros ppc: Add initial memory barrier macros Introduce generic global_data Introduce generic u-boot.h file Introduce generic link symbol file arm: Use sections header to obtain link symbols x86: Change stub example to use asm-generic/sections.h Introduce a basic initcall implementation Define CONFIG_SYS_LEGACY_BOARD everywhere Introduce generic pre-relocation board_f.c Introduce generic post-relocation board_r.c Add spl load feature arm: Enable generic board support Add CONFIG_SYS_SYM_OFFSETS to support offset symbols x86: Use sections header to obtain link symbols Add x86 fields to generic global_data x86: Enable generic board support Add ppc fields to generic global data Adjust board_f for ppc Adjust board_r.c for PowerPC ppc: Enable generic board board tegra: Mark board init files for ARMv4t tegra: Enable generic board for Seaboard.
README | 17 + arch/arm/cpu/armv7/tegra2/config.mk | 2 + arch/arm/include/asm/global_data.h | 7 + arch/arm/include/asm/u-boot-arm.h | 4 - arch/arm/include/asm/u-boot.h | 11 +- arch/arm/lib/Makefile | 4 +- arch/arm/lib/board.c | 1 + arch/avr32/config.mk | 3 + arch/blackfin/config.mk | 3 + arch/m68k/config.mk | 3 + arch/microblaze/config.mk | 3 + arch/mips/config.mk | 3 + arch/nds32/config.mk | 3 + arch/nios2/config.mk | 3 + arch/powerpc/include/asm/global_data.h | 7 + arch/powerpc/include/asm/io.h | 8 + arch/powerpc/include/asm/u-boot.h | 7 + arch/powerpc/lib/Makefile | 4 +- arch/sandbox/config.mk | 3 + arch/sh/config.mk | 3 + arch/sparc/config.mk | 3 + arch/x86/cpu/sc520/sc520_timer.c | 2 +- arch/x86/include/asm/global_data.h | 7 + arch/x86/include/asm/io.h | 8 + arch/x86/include/asm/u-boot-x86.h | 8 - arch/x86/include/asm/u-boot.h | 13 +- arch/x86/lib/Makefile | 4 +- arch/x86/lib/board.c | 1 + board/cm4008/flash.c | 1 + board/cm41xx/flash.c | 1 + board/eNET/eNET.c | 5 - common/Makefile | 4 + common/board_f.c | 888 ++++++++++++++++++++++++++++++++ common/board_r.c | 863 +++++++++++++++++++++++++++++++ common/cmd_bdinfo.c | 6 +- config.mk | 8 + examples/standalone/stubs.c | 7 +- include/asm-generic/global_data.h | 241 +++++++++ include/asm-generic/sections.h | 124 +++++ include/asm-generic/u-boot.h | 155 ++++++ include/common.h | 16 + include/configs/seaboard.h | 2 + include/initcall.h | 25 + lib/Makefile | 1 + lib/initcall.c | 41 ++ 45 files changed, 2504 insertions(+), 29 deletions(-) create mode 100644 common/board_f.c create mode 100644 common/board_r.c create mode 100644 include/asm-generic/global_data.h create mode 100644 include/asm-generic/sections.h create mode 100644 include/asm-generic/u-boot.h create mode 100644 include/initcall.h create mode 100644 lib/initcall.c