[U-Boot] Loading uImage into RAM

[Belisko Marek]

Hi Abdullah,

On Tue, May 6, 2014 at 11:54 AM, Abdullah YILDIZ
<abdullah.mails at gmail.com> wrote:
> Hi Belisko,
>
> On Tue, May 6, 2014 at 12:34 PM, Belisko Marek <marek.belisko at gmail.com> wrote:
>> Hi Abdullah,
>>
>> On Tue, May 6, 2014 at 10:55 AM, Abdullah YILDIZ
>> <abdullah.mails at gmail.com> wrote:
>>> I'm trying to understand how u-boot loads zImage into RAM.
>>>
>>> mkimage is called as
>>>
>>> mkimage -A arm -O linux -T kernel -C none -a 0x80008000 -e 0x80008040
>>> -d arch/arm/boot/zImage /bootImage/uImage
>>>
> Why is entry point different from load address of uImage?
It is set to skip 64bytes (0x40) of mkimage header.
>>> Here, 'a' stands for load address and 'e' stands for entry point (64
>>> bytes are used for wrapping?). However, when loading uImage from
>>> u-boot, boot operation starts at address 0x80100000. Furthermore,
>>> u-boot recognizes the load address and entry point as 0x80008000.
>> Kernel uImage is loaded from NAND to ram at address which $loadaddr
>> points to (check print $loadaddr)
>> or env command which loading kerenl image from NAND.
>> Then by bootm command is copied to address which is specified in
>> mkimage (e.g. 0x80008000). Hope this helps.
>
>
> Kind regards.
>
> abdullah

BR,

marek

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Marek Belisko - OPEN-NANDRA
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