[U-Boot] [PATCH 3/4] imx: hab: Specify IVT padding size

[Bryan O'Donoghue]

On 20/03/18 01:53, Breno Matheus Lima wrote:
> Hi Bryan,
> 
> 2018-03-17 8:06 GMT-03:00 Bryan O'Donoghue <bryan.odonoghue at linaro.org>:
>>
>>
>> On 15/03/18 16:54, Breno Matheus Lima wrote:
>>>
>>> Hi Bryan,
>>>
>>> 2018-03-09 14:35 GMT-03:00 Bryan O'Donoghue <bryan.odonoghue at linaro.org>:
>>>>
>>>> This patch adds IVT_PAD_SIZE at 0xC00. The IVT header is padded to this
>>>> size. Defining the size explicitly makes it possible to use the define to
>>>> locate the start/end of an IVT header without using magic numbers in
>>>> code.
>>>>
>>>
>>> As far as I know the 0xC00 pad size is only mandatory in U-Boot/SPL
>>> images, for instance in some U-Boot images the first 0xC00 should
>>> include IVT + Boot data + DCD table + padding to 0xC00.
>>> Are you using the IVT_PAD_SIZE in your current code? Or this macro
>>> will be used in a next series?
>>>
>>> Thanks,
>>> Breno Lima
>>>
>>
>> All of my images - kernel, u-boot, optee, boot.scr are signed in the same
>> first-stage format with this padding present - for simplicity.
>>
>> Maybe this better named "BOOTROM_IVT_PAD_SIZE" since only the bootrom
>> requires it.
> 
> As far as I know the IVT has a fixed size of 0x20, and the set of IVT
> + Boot Data + DCD cannot exceed 0xC00.
> 
> This value is calculated by the following operation in function
> imximage_generate() at tools/imximage.c:
> alloc_len = imximage_init_loadsize - imximage_ivt_offset;
> 
> Maybe we can rename to something like UBOOT_IMX_HDR_SIZE? We also have
> to ensure this definition is being used by U-Boot code.
> 
> Thanks,
> Breno Lima
> 

So.

I've stupidly called this "PAD_SIZE" and we've gone off on a padding 
size discussion.

This define is supposed to represent the IVT _offset_ in that initial 
BootROM image.

Note to self: the hint is in the variable "setenv ivt_offset=some_number"

Anyway Breno - we could add padding size checks to images but, _this_ 
define is related to IVT offset so... my bad.

I'll redo this patch with a better name :(