Thank you Alex. On 07/02/2022, Deucher, Alexander <alexander.deuc...@amd.com> wrote: > [AMD Official Use Only] > > Most of the register programming in evergreen_gpu_init is required. That > code handles things like harvesting (e.g., disabling bad hardware resources) > and setting sane asic specific settings in some registers. If you don't do > it, work may get scheduled to bad or incorrectly configured hardware blocks > which will lead to hangs or corrupted results. You can probably skip some > of them, but I don't remember what is minimally required off hand. It's > generally a good idea to re-initialize those registers anyway in case > someone has previously messed with them (e.g., manual register munging or > GPU passed through to a VM etc.).
Understood. > > Posting the bios is enough to get you a working memory controller and enough > asic setup to light up displays (basically what you need for pre-OS > console). As Christian mentioned, loading the ucodes will get the > associated engines working so that you can start feeding commands to the > GPU, but without proper configuration of the various hardware blocks on the > GPU, you may not have success in feeding data to the GPU. Understood. I think I wanted a confirmation that the steps I took so far are not completely incorrect and may be just enough to see some GPU activity, before I spend more effort programming other blocks. The feedback and a small but working test helps restore the motivation. Thanks, Amol > > Alex > > > ________________________________ > From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> on behalf of Amol > <suratia...@gmail.com> > Sent: Saturday, February 5, 2022 4:47 AM > To: amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org> > Subject: Minimal GPU setup > > Hello, > > I am learning to program Radeon HD 7350 by reading the radeon > driver source in Linux, and the guides/manuals from AMD. > > I understand the general flow of initialization the driver performs. I > have also been able to understand and re-implement the ATOM > BIOS virtual machine. > > I am trying to program the device up from scratch (i.e. bare-metal). > Do I need to perform all those steps that the driver does? Reading > the evergreen_gpu_init function is demotivating; it initializes many > fields and registers which I suspect may not be required for a minimal > setup. > > Is posting the BIOS and loading the microcode enough to get me started > with running basic tasks (DMA transfers, simple packet processing, etc.)? > > Thanks, > Amol >
