[U-Boot] about CONFIG_SYS_GENERIC_BOARD
Simon Glass
sjg at chromium.org
Fri Aug 16 21:28:26 CEST 2013
Hi David,
On Thu, Aug 15, 2013 at 11:02 PM, FengHua <fenghua at phytium.com.cn> wrote:
> hi Simon,
> I have worked on generic board for a few days, but something confuse me.
> Why it is needed?
> Each processor architecture has different features, this will affect processor specific and board specific code. Putting board_init_* code of each platform into one file with many macro switch make things messy, the board_f.c and board_r.c become very complicated and less readable. Is it really needed?
> We should make it clear that what parts are common between architecture and what parts are specific.
> Actually, I have different opinion with this. Architecture specific board.c file have more advantages. how ahout your opinion?
Scott's reply jogged my memory to reply to this.
I suspect having a board.c for each arch was a good idea at the start,
and it was hard to reconcile the different ordering and init needs of
each arch as it was added. It was much each when porting to a new arch
to just copy one of the existing archs and modify the code until it
works.
Unfortunately, this means we have about 10 different versions of what
turns out to be mostly the same code. The generic board effort was an
attempt to unify these into one. While I agree there are lots of
#idefs I think that is a separate problem, and at least the code is
now all in one file. As a first step it would be nice to sort through
and weed out the arch-specific #idefs in common/board_{f,r}.c.
Related to this is global_data and the board data in bd_t. These
structures have been unified and again found to contain a lot of
common elements across archs.
As a specific example of where having generic board init helps, it is
now possible to add a new feature to all archs without changing 10
different files. For example the trace feature was added that way.
Decide tree support (CONFIG_OF_CONTROL) can in principle be turned on
for any arch by porting it to generic board.
So far ARM and PowerPC support generic board, and x86 and sandbox use
it exclusively (i.e. their old board.c code is removed).
As it turns out, this board.c file is not really very arch-specific,
as Scott says. It should not be a huge job to make aarch64 use it
instead of its own board.c although I am sure there will be a few
curly problems.
We have not talked about this on the list, and it is far to early yet,
but at some point it would be nice to deprecate the old board.c files.
Regards,
Simon
>
> Best Regards.
> David
>
>> -----原始邮件-----
>> 发件人: "Simon Glass" <sjg at chromium.org>
>> 发送时间: 2013年8月16日 星期五
>> 收件人: fenghua at phytium.com.cn
>> 抄送: "U-Boot Mailing List" <u-boot at lists.denx.de>, "trini at ti.com" <trini at ti.com>
>> 主题: Re: [U-Boot] [PATCH v3 0/5] arm64 patch
>>
>> Hi David,
>>
>> On Thu, Aug 15, 2013 at 7:47 AM, <fenghua at phytium.com.cn> wrote:
>> > From: David Feng <fenghua at phytium.com.cn>
>> >
>> > *** BLURB HERE ***
>> > Changes for v3:
>> > - rewrite cache.S and exception.S that partly originated from linux kernel,
>> > so the license should be ok.
>> > - according to scott wood's advice, make the fdt 64bit initrd start address support a seperate patch.
>> >
>> > David Feng (5):
>> > core support of arm64
>> > board support of arm64
>> > arch support 1 of arm64
>> > arch support 2 of arm64
>> > 64bit initrd start address support
>> >
>> > arch/arm64/config.mk | 32 +++
>> > arch/arm64/cpu/armv8/Makefile | 51 ++++
>> > arch/arm64/cpu/armv8/cache.S | 144 ++++++++++
>> > arch/arm64/cpu/armv8/config.mk | 29 ++
>> > arch/arm64/cpu/armv8/cpu.c | 108 ++++++++
>> > arch/arm64/cpu/armv8/exceptions.S | 189 +++++++++++++
>> > arch/arm64/cpu/armv8/start.S | 197 ++++++++++++++
>> > arch/arm64/cpu/armv8/tlb.S | 38 +++
>> > arch/arm64/cpu/u-boot.lds | 73 +++++
>> > arch/arm64/dts/aemv8a.dtsi | 234 ++++++++++++++++
>> > arch/arm64/include/asm/arch-armv8/mmu.h | 117 ++++++++
>> > arch/arm64/include/asm/atomic.h | 115 ++++++++
>> > arch/arm64/include/asm/bitops.h | 153 +++++++++++
>> > arch/arm64/include/asm/byteorder.h | 31 +++
>> > arch/arm64/include/asm/cache.h | 53 ++++
>> > arch/arm64/include/asm/config.h | 41 +++
>> > arch/arm64/include/asm/errno.h | 1 +
>> > arch/arm64/include/asm/global_data.h | 38 +++
>> > arch/arm64/include/asm/gpio.h | 1 +
>> > arch/arm64/include/asm/io.h | 193 +++++++++++++
>> > arch/arm64/include/asm/linkage.h | 49 ++++
>> > arch/arm64/include/asm/posix_types.h | 61 +++++
>> > arch/arm64/include/asm/processor.h | 59 ++++
>> > arch/arm64/include/asm/ptrace.h | 64 +++++
>> > arch/arm64/include/asm/sections.h | 27 ++
>> > arch/arm64/include/asm/string.h | 49 ++++
>> > arch/arm64/include/asm/system.h | 106 ++++++++
>> > arch/arm64/include/asm/types.h | 67 +++++
>> > arch/arm64/include/asm/u-boot.h | 38 +++
>> > arch/arm64/include/asm/unaligned.h | 28 ++
>> > arch/arm64/include/asm/utils.h | 56 ++++
>> > arch/arm64/lib/Makefile | 64 +++++
>> > arch/arm64/lib/board.c | 453 +++++++++++++++++++++++++++++++
>>
>> Instead of this file, it would be good if you could make it use
>> generic board - see CONFIG_SYS_GENERIC_BOARD in the README.
>>
>> > arch/arm64/lib/bootm.c | 211 ++++++++++++++
>> > arch/arm64/lib/cache.c | 282 +++++++++++++++++++
>> > arch/arm64/lib/crt0.S | 129 +++++++++
>> > arch/arm64/lib/interrupts.c | 109 ++++++++
>> > arch/arm64/lib/relocate.S | 72 +++++
>> > arch/arm64/lib/reset.c | 37 +++
>> > arch/arm64/lib/timer.c | 95 +++++++
>> > board/armltd/dts/vexpress64.dts | 215 +++++++++++++++
>> > board/armltd/vexpress64/Makefile | 43 +++
>> > board/armltd/vexpress64/vexpress64.c | 63 +++++
>> > boards.cfg | 1 +
>> > common/cmd_bdinfo.c | 32 +++
>> > common/fdt_support.c | 66 ++---
>> > common/image.c | 5 +-
>> > doc/README.arm64 | 10 +
>> > examples/standalone/stubs.c | 13 +
>> > include/configs/vexpress_aemv8a.h | 200 ++++++++++++++
>> > include/image.h | 1 +
>> > lib/asm-offsets.c | 4 -
>> > 52 files changed, 4509 insertions(+), 38 deletions(-)
>> > create mode 100644 arch/arm64/config.mk
>> > create mode 100644 arch/arm64/cpu/armv8/Makefile
>> > create mode 100644 arch/arm64/cpu/armv8/cache.S
>> > create mode 100644 arch/arm64/cpu/armv8/config.mk
>> > create mode 100644 arch/arm64/cpu/armv8/cpu.c
>> > create mode 100644 arch/arm64/cpu/armv8/exceptions.S
>> > create mode 100644 arch/arm64/cpu/armv8/start.S
>> > create mode 100644 arch/arm64/cpu/armv8/tlb.S
>> > create mode 100644 arch/arm64/cpu/u-boot.lds
>> > create mode 100644 arch/arm64/dts/aemv8a.dtsi
>> > create mode 100644 arch/arm64/include/asm/arch-armv8/mmu.h
>> > create mode 100644 arch/arm64/include/asm/atomic.h
>> > create mode 100644 arch/arm64/include/asm/bitops.h
>> > create mode 100644 arch/arm64/include/asm/byteorder.h
>> > create mode 100644 arch/arm64/include/asm/cache.h
>> > create mode 100644 arch/arm64/include/asm/config.h
>> > create mode 100644 arch/arm64/include/asm/errno.h
>> > create mode 100644 arch/arm64/include/asm/global_data.h
>> > create mode 100644 arch/arm64/include/asm/gpio.h
>> > create mode 100644 arch/arm64/include/asm/io.h
>> > create mode 100644 arch/arm64/include/asm/linkage.h
>> > create mode 100644 arch/arm64/include/asm/posix_types.h
>> > create mode 100644 arch/arm64/include/asm/processor.h
>> > create mode 100644 arch/arm64/include/asm/ptrace.h
>> > create mode 100644 arch/arm64/include/asm/sections.h
>> > create mode 100644 arch/arm64/include/asm/string.h
>> > create mode 100644 arch/arm64/include/asm/system.h
>> > create mode 100644 arch/arm64/include/asm/types.h
>> > create mode 100644 arch/arm64/include/asm/u-boot.h
>> > create mode 100644 arch/arm64/include/asm/unaligned.h
>> > create mode 100644 arch/arm64/include/asm/utils.h
>> > create mode 100644 arch/arm64/lib/Makefile
>> > create mode 100644 arch/arm64/lib/board.c
>> > create mode 100644 arch/arm64/lib/bootm.c
>> > create mode 100644 arch/arm64/lib/cache.c
>> > create mode 100644 arch/arm64/lib/crt0.S
>> > create mode 100644 arch/arm64/lib/interrupts.c
>> > create mode 100644 arch/arm64/lib/relocate.S
>> > create mode 100644 arch/arm64/lib/reset.c
>> > create mode 100644 arch/arm64/lib/timer.c
>> > create mode 100644 board/armltd/dts/vexpress64.dts
>> > create mode 100644 board/armltd/vexpress64/Makefile
>> > create mode 100644 board/armltd/vexpress64/vexpress64.c
>> > create mode 100644 doc/README.arm64
>> > create mode 100644 include/configs/vexpress_aemv8a.h
>> >
>>
>> Regards,
>> Simon
>
>
>
>
>
>
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