ACRN Project Technical Community Meeting Minutes - 4/10/2019
Meeting Minutes Archive: o Google doc: https://drive.google.com/drive/u/2/folders/111m6iU3PjSZebOOKzLagYPUWMvseGLeU
ACRN Project TCM - 10th April 2019
ACRN brochure updated with architecture picture.
Download foil from ACRN Presentation->ACRN_TCM->WW15’19
Q1: What’s the difference between GPIO controller and SD card controller?
A1: SD controller is used to control SD memory cards and SDIO cards, and GPIO controller is used to control all of GPIO defined by the platform. Usually SD controller applies GPIO resources from GPIO controller for Card detection or power state changing.
Q2: Will GPIO have its controller or just mapping in memory address?
A2: Yes, GPIO has its own controller, GPIO registers can be mapped to system memory, and user can access GPIO registers via the MMIO directly.
Q3: SD card CS and IRQ pin?
A3: For SD card detection, it usually use a GPIO as IRQ source. If the SD card is inserted/removed, the IRQ will be triggered, and SD device driver can read the GPIO value to check the card state(insertion or removal).
Q4: For the corner case, what if multi VM use same GPIO pin? Can Virtual GPIO handle such case? Is there any error message showing up?
A4: one native GPIO pin can only map to one VM. Virtual GPIO will ignore the pin if it has already been occupied by other VMs or SOS device driver. If a GPIO is ignored, the GPIO mediator will print the GPIO is in busy log when GPIO mediator initialization.
Q5: Is the macro a standard definition in the virtual GPIO?
A5: Yes, it is implemented with ACPI control method.
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