07:50 <sajattack> I'm wondering what would be the best way to create a userspace/cpu-accessible framebuffer with litepcie, to make sort of a rasterizer card or something like that. I have an acorn which probably doesn't have enough io to actually drive a display (and no baseboard), has anyone tried something like this? I'm not too familiar with pcie or wishbone for that matter. But curious how someone would approach this

07:51 <sajattack> is there a way to just map a block of memory that both can share under linux?

07:51 <tnt> sajattack: you can create a memory mapped without ( BAR ) that just exposes your VRAM.

07:51 <tnt> s/without/window/

07:52 <sajattack> when you say vram, do you mean on the fpga or on my pc's gpu?

07:52 <tnt> on the fpga

07:54 <sajattack> yeah so that's kind of what I was thinking, how does the memory mapping work?

07:59 <sajattack> https://github.com/enjoy-digital/litepcie/issues/34

07:59 <sajattack> using this example, is it just resource0 == the vram/dram?

08:09 <tnt> yes you could map bar0 directly to your vram or some part of it.

08:09 <tnt> you could also define another BAR

08:10 <tnt> (BAR0 is usually used for mmio registers)

08:11 <sajattack> cool

08:11 <tnt> Although not sure if/how litepci supports multiple BAR.

08:12 <tnt> Ok, it doesn't so you have to use bar0 (or a part of it).

08:13 <tnt> Note that this won't exactly be fast ...

08:15 <sajattack> I found this issue about a similar thing too https://github.com/enjoy-digital/litepcie/issues/54

08:20 <sajattack> haha brrrrr https://github.com/enjoy-digital/litepcie/pull/107

08:23 <sajattack> this looks like it's for cuda though

08:25 <sajattack> yeah so I guess just do the 54 one and access the memory with the cpu one pixel at a time?

08:26 <sajattack> or try to find a way to map it to the gpu 🤔

08:51 <tnt> I don't understand what you mean. If you expose some RAM on the FPGA through a BAR, yeah, the CPU will access it through PCIe one pixel at a time.

08:51 <sajattack> nevermind

08:58 <whitequark[cis]> i think you could maybe use MTRRs to make it cacheable?

09:18 <sajattack> vivado keeps failing to download lol

21:44 <cr1901> If you are a Tera Term user (Windows), and use LiteX, would you be willing to try this plugin? https://github.com/cr1901/teraterm-litex

21:44 <cr1901> It _does_ work for me, including the installers. But I don't have a second machine to try a "no dev env" install on.