[PATCH 3/3] bootm: add initial FIT support

[Yegor Yefremov]

On Tue, Jan 5, 2016 at 2:50 PM, Marc Kleine-Budde <mkl at pengutronix.de> wrote:
> On 01/05/2016 02:05 PM, Yegor Yefremov wrote:
>>>>>> What about unsigned images?
>>>>>
>>>>> That's not our use case. We use plain zImages instead.
>>>>
>>>> The solution would be to introduce an option like in U-Boot?
>>>>
>>>> CONFIG_FIT_SIGNATURE:
>>>>
>>>> This option enables signature verification of FIT uImages,
>>>> using a hash signed and verified using RSA. If
>>>> CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
>>>> hashing is available using hardware, RSA library will use it.
>>>> See doc/uImage.FIT/signature.txt for more details.
>>>
>>> Technically possible, but I'm not sure what are the benefits of using
>>> fit images, if you don't need signatures. barebox implements
>>> freedesktop.org's bootspec and this is IMHO the way to go.
>>
>> For me FIT is just a way to have a kernel and a bunch of device tree
>> blobs in one file. Signed or not signed is an option for me. Just like
>> U-Boot implements it. This is user responsibility.
>
> Send patches. :D

I'll prepare one on top of yours. So far I can boot into Linux on my
am335x based board, so

Tested-by: Yegor Yefremov <yegorslists at googlemail.com>

>> In my use case I just read device ID from EEPROM, load my
>> kernel-fit.itb and select needed DTB via this ID. This way I have only
>> one SD card image, that can be run on more, than 10 different devices
>> using the same core module.
>
>>>>>> I also get: unsupported algo crc32
>>>>>> Is it intended to be supported?
>>>>>
>>>>> Not for our usecase - feel free to add crc32 support.
>>>>
>>>> OK.
>>>>
>>>> But what about FIT configuration selection syntax?
>>>
>>> What's this?
>>
>> Have you seen my comments to this patch regarding
>> fit_open_configuration() routine?
>
> sorry - I've missed that. Too many quoted lines. :D
>
>>> > +static int fit_open_configuration(struct fit_handle *handle, int num)
>>> > +{
>>> > +       struct device_node *conf_node = NULL, *sig_node;
>>> > +       char unit_name[10];
>>> > +       const char *unit, *desc;
>>> > +       int ret, level;
>>> > +
>>> > +       conf_node = of_get_child_by_name(handle->root, "configurations");
>>> > +       if (!conf_node)
>>> > +               return -ENOENT;
>>> > +
>>> > +       if (num) {
>>> > +               snprintf(unit_name, sizeof(unit_name), "conf@%d", num);
>>
>> This is not working for my *.its file:
>> https://github.com/visionsystemsgmbh/onrisc_br_bsp/blob/master/board/vscom/baltos/kernel-fit.its
>> U-Boot is working with bootm ${loadaddr}#conf${board_name}
>>
>> For Barebox I've changed this line to
>>
>> snprintf(unit_name, sizeof(unit_name), "conf%d at 1", num)
>>
>> This is how I start Linux: bootm /boot/kernel-fit.itb@$global.board.id
>>
>> What is the standard for providing FIT configuration?
>
> Don't know. Is there a spec in the u-boot sources, otherwise use the code.

Will look closer at U-Boot code and send a patch.