On 03/23/2017 04:15 PM, Lucas Stach wrote:
Hi,
Am Donnerstag, den 23.03.2017, 16:04 +0100 schrieb gianluca:
Hello,
I was looking around to have a common Barebox binary to bootup two
boards based on iMX6 SoC.
The PCB are at 99.8% the same.
PCB#0 has iMX6QP and a VDDCore of 1.38V (LDO enabled)
PCB#1 has iMX6DL and a VDDCore of 1.32V (LDO enabled)
I was wondering how other boards (like Nitrogen6x) does for booting.
As soon as my boards have the same DDR Memory routing and types, the oly
thing I can think is the different memory address space for DDR controller.
Even if the external memory is the same, you need 2 different DRAM
setups. Quad and DualLite differ in IOMUX setup and maximum DRAM
frequency, the QuadPlus needs additional setup for the NoC.
So you need two DRAM setup only? And no problem for NoC. Our boards will
have only QuadPlus and DualLite.
In fact, the Nitrogen6x boards, differs from the #include of the ddr
controller (one is for dual-lite, the other for quad).
For the Nitrogen boards we just build multiple images for different
SoC/DRAM configurations. This is the easiest and most reliable way of
dealing with this issue.
So you will have different device-tree .dts file? One for each SoC even
if the pinout are the same?
In this way, having two DRAM Setups, two IOMUX setup, different DRAM
Frequencies and two device-tree blobs, this leads me to a conclusion:
-- They are TWO DIFFERENT BOARDS (even the PCB and the pinouts are the same)
Luckly the Linux kernel is the same, and even the rootfilesystem too.
But I do not found any switch between choosing one Soc or another.
Where is done the startup entry?
If you want a single binary, you need build a 2 stage barebox. First
stage needs to be loaded into SRAM, then you can look at which board you
are running and do the specific DRAM setup. Then you can load the bigger
2nd stage into DRAM, where you again need to look at the board you are
running at and select the correct devicetree for barebox to use.
And the maximum clock speed??? Those SoC has different clock maximum
speed, so I think someone has to tell it to run @800 Mhz or @1Ghz. Is
this true?
Clock speeds are defined by the CPU OPPs in the devicetree and the fuse
settings of the SoC.
Ok, I will check that.
Thank you for now,
--
Eurek s.r.l. |
Electronic Engineering | http://www.eurek.it
via Celletta 8/B, 40026 Imola, Italy | Phone: +39-(0)542-609120
p.iva 00690621206 - c.f. 04020030377 | Fax: +39-(0)542-609212
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