Hi, I would like to access the GPIO through mmap but I can't find in the documentation the base address of the GPIO controller or any other information about mmap gpio. Where can I find it?
What GPIO? The Braswell side or the Arduino side? Only the Braswell side could possibly be addressed through mmap but why if you have an Arduino on board? If you definitely want to use mmap you have to check the intel documentation of the Braswell CPU in your Udoo.
Sorry, I was talking about the Braswell. My use-case is not trivial as I need to map physical memory address to the virtual space manually and pass them to virtual machines. About the Arduino micro-controller, I'm not sure how to map and make it accessible from inside the VM. Thanks for your help anyway!
re: map physical memory address to the virtual space manually and pass them to virtual machines Oh, that's a big mountain to climb. I've heard of IOMMU virtualization (VT-d) and of course CPU virtualization (VT-x). Yours is new to me.
I couldn't find much about the GPIO registers physical addresses on the Intel documentation for the processor on my UDOO (Intel Atom x5-E8000 Processor), maybe I just didn't find the right document. Anyway, I've contacted Intel and they told me that I should contact you to receive more details about the issue (because you are an OEM and might have customized the hardware/software).
I am not Udoo. @Laura is. If she is not responding please open a ticket at Udoo customer support. https://www.udoo.org/customer-care/open.php
BTW, UDOO x86 uses Braswell and Braswell does not support VT-d (IOMMU and memory-mapped IO) in virtualization context. Only in Goldmont, e.g., Apollo Lake, Intel started to introduce VT-d into ATOM class SoCs.
I know this is an old thread, but I got here because I was looking for this information and I finally found it somewhere else. The base address of the GPIO registers is 0xfed80000 I found the information here: https://github.com/coreboot/coreboot/blob/master/src/soc/intel/braswell/include/soc/iomap.h I did some simple memory map tests. I might create another post with the info on how to do it.
