[U-Boot] [RFC PATCH 0/5] move boot0 hook in the beginning for armv7

Tue Jun 13 17:10:24 UTC 2017

On Tue, Jun 13, 2017 at 1:14 PM, Dr. Philipp Tomsich
<philipp.tomsich at theobroma-systems.com> wrote:
>
>> On 13 Jun 2017, at 03:40, Kever Yang <kever.yang at rock-chips.com> wrote:
>>
>> Hi Simon,
>>
>>
>> On 06/09/2017 08:27 PM, Simon Glass wrote:
>>> Hi Kever,
>>>
>>> On 7 June 2017 at 04:55, Kever Yang <kever.yang at rock-chips.com> wrote:
>>>> Simon,
>>>>
>>>>
>>>>
>>>> On 06/07/2017 11:15 AM, Simon Glass wrote:
>>>>> Hi Kever,
>>>>>
>>>>> On 6 June 2017 at 20:41, Kever Yang <kever.yang at rock-chips.com> wrote:
>>>>>> Simon,
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 06/07/2017 05:08 AM, Simon Glass wrote:
>>>>>>> Hi Kever,
>>>>>>>
>>>>>>> On 31 May 2017 at 04:50, Kever Yang <kever.yang at rock-chips.com> wrote:
>>>>>>>> I think the boot0 hook is suppose to add some data in the very
>>>>>>>> beginning
>>>>>>>> of the SPL image, am I right?
>>>>>>>>
>>>>>>>> Rockchip SoCs bootrom design is like this:
>>>>>>>> - First 2KB or 4KB internal memory is for bootrom stack and heap;
>>>>>>>> - Then the first 4-byte suppose to be a TAG like 'RK33';
>>>>>>>> - The the following memory address end with '0004' is the first
>>>>>>>>     instruction load and running by bootrom;
>>>>>>>>
>>>>>>>> Example for RK3288:
>>>>>>>> Before this patch set, the SPL_TEXT_BASE is ff704004, and image write
>>>>>>>> to
>>>>>>>> media device after mkimage like this:
>>>>>>>>
>>>>>>>> ff704000: 32334b52 00000000 00000000 00000000    RK32............
>>>>>>>> ff704010: 00000000 00000000 00000000 00000000    ................
>>>>>>>> ff704020: ea00000f e59ff014 e59ff014 e59ff014    ................
>>>>>>>> ff704030: e59ff014 e59ff014 e59ff014 e59ff014    ................
>>>>>>>>
>>>>>>>> Where the first instruction from bootrom is '00000000', which is a
>>>>>>>> undefined instruction.
>>>>>>>> The '_start' and 'reset' have to align to 0x20 for the requirement of
>>>>>>>> VBAR, the memory offset '004'~'01c' are filled with '00000000'.
>>>>>>>>
>>>>>>>> We can use the boot0 hook to fix this issue, after this patch set,
>>>>>>>> the SPL_TEXT_BASE is ff704000 and image write to media device after
>>>>>>>> mkimage like this:
>>>>>>>>
>>>>>>>> ff704000: 32334b52 ea00001d e320f000 e320f000    RK32...... ... .
>>>>>>>> ff704010: e320f000 e320f000 e320f000 e320f000    .. ... ... ... .
>>>>>>>> ff704020: ea000016 e59ff014 e59ff014 e59ff014    ................
>>>>>>>> ff704030: e59ff014 e59ff014 e59ff014 e59ff014    ................
>>>>>>>>
>>>>>>>> The first instruction from bootrom is a 'b reset', and memory of
>>>>>>>> '008'~'01c' are filled with 'nop' instruction.
>>>>>>>>
>>>>>>>> This patch set does not provide patch for socfpga, bcm and sunxi SoCs
>>>>>>>> which also
>>>>>>>> enable BOOT0_HOOK, so this is a RFC patch, please advice how to make it
>>>>>>>> compatible with those three platforms.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Kever Yang (5):
>>>>>>>>     armv7: move boot hook before '_start'
>>>>>>>>     rockchip: boot0: align to 0x20 for armv7 '_start'
>>>>>>>>     rockchip: enable BOOT0_HOOK for SoCs
>>>>>>>>     rockchip: configs: use aligned address for SPL_TEXT_BASE
>>>>>>>>     rockchip: mkimage: use spl_boot0 for all Rockchip SoCs
>>>>>>>>
>>>>>>>>    arch/arm/include/asm/arch-rockchip/boot0.h |  9 ++++++++-
>>>>>>>>    arch/arm/lib/vectors.S                     | 19 ++++++++++---------
>>>>>>>>    arch/arm/mach-rockchip/Kconfig             |  3 +++
>>>>>>>>    include/configs/rk3036_common.h            |  2 +-
>>>>>>>>    include/configs/rk3288_common.h            |  2 +-
>>>>>>>>    tools/rkcommon.c                           |  8 ++++----
>>>>>>>>    6 files changed, 27 insertions(+), 16 deletions(-)
>>>>>>>>
>>>>>>>> --
>>>>>>>> 1.9.1
>>>>>>>>
>>>>>>> Do will still need this series now that (I think) we have a fix for
>>>>>>> the return-to-brom feature in u-boot-rockchip/master?
>>>>>>
>>>>>> Could you point me out exactly which fix do you talking about?
>>>>> These ones:
>>>>>
>>>>> a079e52d35 rockchip: mkimage: set init_boot_size to avoid confusing the
>>>>> boot ROM
>>>>> ee2c63912b rockchip: mkimage: force 2KB alignment for init_size
>>>>> 99c700c794 rockchip: mkimage: add support for verify_header/print_header
>>>>>
>>>>>> This is not about return-to-brom, it's about the first instruction from
>>>>>> Bootrom to SPL.
>>>>>> So this is need for all Rockchip armv7 SoCs.
>>>>> OK, how did we survive before? What has changed to make this series
>>>>> needed?
>>>>
>>>> After check with JTAG, I find that I'm wrong with cmd code '00000000',
>>>> this is 'andeq r0, r0, r0', but not undefined in armv7, so it can work.
>>>>
>>>> I still want this patch set applied because it's better to make all the
>>>> Rockchip's
>>>> SPL have the same format(with 4-byte TAG space reserved), and the ddr binary
>>>> from Rockchip always have pre-padding 4-byte TAG, with this patch set, we
>>>> can replace each other easily and work with one mkimage tool.
>>> I'm not sure how to apply this since on the other thread[1] Marek says
>>> it will break socfpga.
>>
>> I know this must break socfpga platform, and as I have said in cover letter,
>> I think this patch also break bcm and sunxi platform, I add 'RFC' for this patch
>> set because I don't know the detail requirement of hook0 for other 3 platform,
>> I'm not asking if this patch set break other 3 platforms or not, but I'm asking for
>> the solution for those 3 platform so that we can apply this patch set.
>
> The following platforms have a boot0-hook implemented:
>
> ./arch/arm/include/asm/arch-rockchip/boot0.h
> ./arch/arm/include/asm/arch-bcm235xx/boot0.h
> ./arch/arm/include/asm/arch-sunxi/boot0.h
> ./arch/arm/include/asm/arch-bcm281xx/boot0.h
> ./arch/arm/mach-socfpga/include/mach/boot0.h
>
>> I think my patch is correct in what HOOK0 wants to do, just like Philipp's opinion
>> in another mail.
>> I hope to get help from maintainer for socfpga, bcm, sunxi platform.

for sunxi32 boot0 hook does normal execution (b reset) but the image
changed 4 bytes with this change.

w/o the change:
0000000 0016 ea00 4765 4e4f 422e 3054 cf32 4cc6
0000010 6000 0000 5053 024c 0000 0000 0000 0000

with the change:
0000000 0016 ea00 4765 4e4f 422e 3054 da15 4b6f
0000010 6000 0000 5053 024c 0000 0000 0000 0000

of-course board not booting.

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.