[yocto] [meta-raspberrypi][PATCH v3] u-boot: Simplify boot script

[Jonathan Liu]

Hi Paul,

On 6 November 2016 at 22:57, Paul Barker <paul at paulbarker.me.uk> wrote:
> On Sat,  5 Nov 2016 12:50:07 +1100
> Jonathan Liu <net147 at gmail.com> wrote:
>
>> A patch is added to check if the firmware loaded a device tree blob
>> into memory and set the fdt_addr_r variable if it is found. The U-Boot
>> script will then read the command line arguments generated by the
>> firmware from the device tree and boot the kernel with the command
>> line arguments and the loaded device tree.
>>
>> This allows things like MAC address, board revision and serial number
>> to be correctly configured and options in config.txt to be used.
>>
>> Signed-off-by: Jonathan Liu <net147 at gmail.com>
>> ---
>> Changes in v3:
>>  - Removed incorrect check if fdt_addr_r is already set. The check
>>    condition was inverted and fdt_addr_r variable is always set to
>>    0x100 by default.
>> Changes in v2:
>>  - Instead of setting device_tree_address to 0x100 in config.txt, patch
>>    U-Boot to detect the device tree blob address if it was loaded.
>>
>
> I'm still getting the same "Could not find a valid device tree" failure
> on the model B+.
>
> I've tried running vcdbg but got the following error from the kernel
>
>     vc_mem_mmap: length 4096 is too big
>
> vcdbg itself then said:
>
>     debug_sym: AccessVideoCoreMemory: mmap failed: Invalid argument(22)
>     debug_sym: OpenVideoCoreMemoryFileWithOffset: ReadVideoCoreMemory @VC_SYMBOL_BASE_OFFSET (0x00002800) failed
>
>     Unable to open videocore memory access: -5
>
> This was after adding "dtdebug=on" to config.txt
>
> Not sure where to go next with this. I might need to go off on a Yak
> shaving mission and find out why the mmap is failing.

A patch is being worked on upstream - https://patchwork.ozlabs.org/patch/692412/
I think we will wait until it is accepted upstream and then backport it.

Regards,
Jonathan