[U-Boot] Galileo instructions

Tue Sep 15 04:06:17 CEST 2015

Hi Simon,

On Tue, Sep 15, 2015 at 9:52 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 14 September 2015 at 08:32, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Simon,
>>
>> On Mon, Sep 14, 2015 at 9:59 PM, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Hi Simon,
>>>
>>> On Mon, Sep 14, 2015 at 8:51 PM, Simon Glass <sjg at chromium.org> wrote:
>>>> Hi Bin,
>>>>
>>>> On 14 September 2015 at 06:49, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>>
>>>>> Hi Simon,
>>>>>
>>>>> On Mon, Sep 14, 2015 at 8:45 PM, Simon Glass <sjg at chromium.org> wrote:
>>>>> > Hi Bin,
>>>>> >
>>>>> > On 13 September 2015 at 03:28, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>>> >> Hi Simon,
>>>>> >>
>>>>> >> On Sun, Sep 13, 2015 at 5:06 AM, Simon Glass <sjg at chromium.org> wrote:
>>>>> >>> Hi Bin,
>>>>> >>>
>>>>> >>> I have a Galileo Gen 2 and am trying to get U-Boot to start on it. The
>>>>> >>> first problem I have is that the schematic says the chip is a W25Q64FV
>>>>> >>> which I think is an 8MB part, but the image produced is only 1MB.
>>>>> >>
>>>>> >> Yes, the board has an 8MB SPI flash, but U-Boot (u-boot.rom) only
>>>>> >> utilizes the last 1MB.
>>>>> >>
>>>>> >>>
>>>>> >>> Also I know that there is a Gen 1 and a Gen 2. I recall you saying
>>>>> >>> that U-Boot supports the Gen 2 but can easily support the Gen 1. But
>>>>> >>> perhaps I have done something wrong.
>>>>> >>>
>>>>> >>
>>>>> >> I've verified U-Boot can boot on both gen1 and gen2 boards.
>>>>> >
>>>>> > Thanks.
>>>>> >>
>>>>> >>> I downloaded the BSP from here:
>>>>> >>>
>>>>> >>> https://downloadcenter.intel.com/download/23197/Intel-Quark-BSP
>>>>> >>>
>>>>> >>> File name: Board_Support_Package_Sources_for_Intel_Quark_v1.1.0.7z
>>>>> >>> Version: 1.1.0 (Latest)
>>>>> >>>
>>>>> >>> Date: 03/03/2015
>>>>> >>> Size: 2.72 MB
>>>>> >>>
>>>>> >>> Any hints? I am using a dediprog em100 with a test clip over the flash chip.
>>>>> >>>
>>>>> >>
>>>>> >> It's not clear to me what issue you got. It looks like there might be
>>>>> >> some issue for dediporg em100 to handle the rom size mismatch? If this
>>>>> >> is the case, you can just create an 8MB u-boot.rom with the 1MB
>>>>> >> version with other 7MB filled up with 0xFFs.
>>>>> >
>>>>> > OK I did this and it works, thanks.
>>>>>
>>>>> So it's indeed the dediprog em100 cannot handle the rom mismatch?
>>>>>
>>>>> > Why don't we just change the ROM size? This point is not mentioned in README.x86.
>>>>> >
>>>>>
>>>>> 1MB is enough for U-Boot. u-boot.rom does not necessarily have to
>>>>> match the SPI flash size. And on Galileo since there is no Intel ME,
>>>>> so we don't need to create a whole 8MB rom. This is the same as Intel
>>>>> CrownBay, which has a 2MB SPI flash, but still 1MB u-boot.rom.
>>>>
>>>> What is the benefit of this mismatch? I only see the down-side at
>>>> present (user confusion, unbootable .rom).
>>>
>>> I don't see this as a down-side. Why did you call this as unbootable
>>> .rom? The Dediprog em100 does not work does not mean it is not
>>> bootable. The assumption is to program this 1MB u-boot.rom to the last
>>> 1MB of the SPI flash. Perhaps you need contact Dediprog to fix their
>>> em100 tool to handle such rom mismatch correctly. Or maybe there is
>>> some parameter to control such behavior that you are not aware of. I
>>
>> I don't have a dediprog em100 tool, but based on the user manual [1] I
>> found on their website, the em100 tool does support such scenario. If
>> you check page 22, the 'Configuration Setting' window allows you can
>> specify the flash offset at which you download the rom file. The
>> corresponding command line parameter is at page 33, which is '-a
>> addr'. For example, on Galileo board, you need specify '-a 0x700000'
>> (I believe).
>
> Maybe that is the windows version? My version of the utility does not
> have that option.

Looks it is the Windows version. So you are using Linux version which
does not have such feature? It's quite odd if that's the case.

>
>>
>>> think this is quite a normal use case, as is exactly the same as other
>>> architectures, that u-boot.bin does not have to match the flash media
>>> size. Say on PowerPC BookE processors, the NOR flash media can be 8MB,
>>> 16MB, but the generated bootable u-boot.bin is 512KB, 1MB, etc (Check
>>> these Freescale QorIQ boards in U-Boot). Users need program u-boot.bin
>>> to the last 512KB or 1MB in the NOR flash.
>>>
>>> And I don't see this is a confusion. Perhaps all x86 boards you've
>>> played before require the Intel ME firmware, in which case your
>>> u-boot.rom MUST match the SPI flash size, but we have to realize Intel
>>> ME is an optional feature and not every x86 board requires that. I am
>>> afraid this is a preconceived idea instead of confusion.
>>>
>>
>> And one more use case from my experience FYI, on Intel Bayley Bay
>> which is a BayTrail based board, and it requires Intel ME, as you see
>> its u-boot.rom is 8MB which is the same as MinnowMax. But I did a
>> trick in my debugging, that I changed the rom size to 1MB and remove
>> the Intel ME Kconfig option from 'menuconfig'. This way I only need
>> program a 1MB u-boot.rom starting from 0x700000. Only the very first
>> time I touch this board, I chose to program the complete 8MB
>> u-boot.rom to the SPI flash. Programming 1MB takes quite less time
>> than 8MB, not to mention the first 5MB (flash descriptors plus Intel
>> ME firmware) is always the same.
>
> OK I see, but in that case you are building a partial image. This is
> an optimisation which could be done another way, e.g. by cutting off
> the top part of the image.
>

It is not a partial *image*. It is a complete image which can boot on
the board. It is not working because we programmed (ie: using Dediprog
sf100) or downloaded (ie: using Dediprog em100) to a wrong place. We
probably could say it is a partial *rom*, if we specify *rom*
corresponds to the whole SPI flash.

> I think the .rom file should actually be writen to the ROM as is. To
> me it seems clearer. Perhaps we should provide another file which is

No, I don't think so. The SPI flash is only the flash media to store
bootloader, but the bootloader file size does not have to match the
SPI flash size. The SPI flash can have some places to store kernel
image, root file system, etc. We cannot create a u-boot.rom which
occupies all these spaces.

> optimised - e.g. a minimal file like u-boot.rom.min? Also even 1MB is
> a lot more than you normally need to write - does the flashing tool
> you use provide options to write a partial image?

Again, it is not a partial *image*. It is a complete *image*. The
flash tool (I am using Dediprog sf100) supports writing a file to
whatever flash offset. And I believe, such feature is probably
supported by all flash tools in the market as it is a very basic and
common use case. Why are you forcing users to always erase the whole
SPI flash and program a file which corresponds to the whole SPI flash?
It is not only SPI flash, but also the case for NOR flash, NAND flash
programmers that I have ever used. All of these support writing a file
to a particular flash offset.

>
>>
>> [1] http://www.dediprog.com/save/79.pdf/to/DP_EM100Pro_user%20manual_V1.3.pdf
>

Regards,
Bin