[U-Boot] [PATCH 2/9] sunxi: Move SPL s_init() code to board_init_f()

[Hans de Goede]

Hi Simon, Siarhei,

On 01-02-15 21:59, Simon Glass wrote:
> Hi Siarhei,
>
> On 1 February 2015 at 11:37, Siarhei Siamashka <siarhei.siamashka at gmail.com>

<snip>
>> A comprehensive FEL usage guide is supposed to be in the linux-sunxi
>> wiki. But it might be not very up to date with the mainline u-boot
>> usage.
>>
>> Anyway, first just clone the https://github.com/linux-sunxi/sunxi-tools
>> repository and build it. This will provide you with the x86 binary of
>> the 'fel' tool, which is used on your desktop PC to talk with the
>> device.
>>
>> Then connect the device to your PC using a "USB A to USB mini/micro B"
>> cable. And reset the board while keeping the "FEL" button pressed. The
>> button might be labelled as "UPGRADE" on your pcduino3 board:
>> http://linux-sunxi.org/LinkSprite_pcDuino_V3#FEL_mode
>>
>> Then just run "fel ver" command:
>> http://linux-sunxi.org/FEL#Running_the_fel_tool
>>
>> If everything is fine, it should respond with something like this:
>> AWUSBFEX soc=00162500(A13) 00000001 ver=0001 44 08 scratchpad=00007e00
>> 00000000 00000000
>>
>> Now you can use "write" commands to upload data to SRAM. And "exe"
>> command to execute functions on the device (works as some kind of RPC):
>> http://linux-sunxi.org/FEL/USBBoot#Manual_loading
>>
>> As a simple test, you can upload just a single "bx lr" instruction
>> (compiled in ARM mode) to the address 0x2000 and try to execute it.
>> In the case if your code screws up something and does not return
>> control to the BROM correctly, then the "fel" tool can't communicate
>> over USB anymore and just timeouts. Regarding the address space, you
>> can use SRAM addresses starting from 0x2000 up to something like 0x5E00
>> (that's where the stack pointer is set). This was a description of a
>> "bare metal" FEL usage.
>>
>> Now as for the u-boot support. You can compile and run u-boot in the FEL
>> mode configuration on pcduino3 in the following way:
>>
>> make CROSS_COMPILE=arm-none-gnueabi- Linksprite_pcDuino3_felconfig
>> make CROSS_COMPILE=arm-none-gnueabi- -j2
>>
>> fel write 0x2000 spl/u-boot-spl.bin
>> fel exe 0x2000
>>
>> sleep 1 # Wait for DRAM initialization to complete
>
> i.e. wait for U-Boot SPL to return to the BROM?
>
>>
>> fel write 0x4a000000 u-boot.bin
>> fel exe 0x4a000000
>>
>> Please note the use of '*_felconfig' instead of '*_defconfig'.
>> And also right now the FEL mode support is broken. That's why the
>> http://lists.denx.de/pipermail/u-boot/2015-January/203282.html
>> patchset tried to address this problem.
>>
>
> OK that looks like an excellent guide, thank you. I will make some time to
> take a more detailed look at this as soon as I can, but definitely in the
> next few days.

I've been reading all threads on this, thank you both for looking into this,
since you're on it I'm going to leave this be (and not review / apply
Siarhei's patches for this), and we can revisit this later, with hopefully a
better fix.

Thanks & Regards,

Hans