Geoffrey McRae gnif

These are notes on modifications to make to the IBM branded 2RU APC SmartUPS 3000VA UPS to make it operate as a hybrid solar inverter/ups.

Disable the charging circuit

Since I am charging from solar I do not want the UPS to be able to charge the externally attached battery array, on this model this is very simply done by inserting a diode on the RED and BLACK wires coming from the front of the ups (charging module) to J4 on the main PCB to prevent reverse current flow to the batteries. The diode is required or the charging module wont be powerered at startup which puts the unit into a fault mode.

Coltrolling the output

Initially I was using a solid state relay to disconnect the feed in to the UPS when I was getting enough power to charge the batteries and run my equipment from solar, however this has been causing issues with RCDs (residual current devices) due to the massive inrush current when the UPS is re-connected to the supply. As such I have reverse engineered enough of the circuit to understa

	At a high level we treat each GPU as an SOC. The SOC is built from a set of IP blocks (intellectual property) that provide various functionality. The driver is designed around the idea that each SOC is a collection of IP blocks. The IP blocks are versioned so that we can write a single driver component for all SOCs that contain that IP version. So, the general list of IPs that you may see on an SOC:
	DCE - Display and Compositing Engine. This is the display block.
	GFX - Graphics and Compute. This is the graphics and compute (shader) block.
	GMC - Graphics Memory Controller. This is the memory controller for the GPU. It provides support for VRAM and vitualized access to VRAM and system memory for GPU clients.
	SDMA - System DMA. This is a general purpose DMA engine on the GPU. It's generally used for paging of GPU memory and for things like transfer queues in user mode acceleration drivers.
	UVD - Unified Video Decode. This is the video decode and encode block on the GPU. It started out as decode only