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

[Kever Yang]

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.

Thanks,
- Kever
>
> Regards,
> Simon
>