Saturday, 2019-05-04

*** tpb has joined #litex00:00
futarisIRCcloudSo I tried hooking up vexriscv (linux) to a Spartan 6 by modifying the linux-on-litex-vexriscv repo. The smallest one that would place & route is a xc6slx25. Too many SLICEMs for the xc6slx16 or the xc6slx9 in the mimasv2.04:58
keesjwhat is mimasv2?05:54
futarisIRCcloud50 USD FPGA board06:12
keesjI see yea . all my sparan boards are ... not good enough (papilio pro lx9 , lambdaconcept lx16)06:34
futarisIRCcloudThe cheapest FPGA chip that it might work on, is probably the: LFE5U-12F ...06:45
futarisIRCcloud / --idcode 0x2111104306:47
tpbTitle: Missing support for LFE5-12F devices · Issue #55 · SymbiFlow/prjtrellis · GitHub (at
*** Dolu has joined #litex08:10
_florent__Hi, i just added SPI flash support to the arty target in
tpbTitle: GitHub - enjoy-digital/linux-on-litex-vexriscv: Experiments with Linux on LiteX-VexRiscv (at
_florent__if anyone want to test, the only thing to do is install openocd, litex and do ./ --flash09:43
*** Dolu has quit IRC10:20
*** Dolu1990 has joined #litex10:21
Dolu1990Nice for the flash :D10:24
futarisIRCcloudDolu1990: Did you say you only have a DE1-SoC (Cyclone V) board?11:03
Dolu1990As a linux ready board, yes, or also a DE0-70, but that's realy old stuff12:23
Dolu1990I will probably get a new board, with a better fit12:24
Dolu1990Ahh no, DE2-70. Currently, Artix look sexy, for speed reasons, but ECP5 seem also great for price reasons12:39
Dolu1990Also have to look about opensource synthesis, avoiding the vendor flow is always welcome ^.^12:42
Dolu1990LFE5U-12F + cheap SDRAM + flash would mean around 10$ linux ready FPGA BOM, and maybe that's realy a thing ?12:49
*** futarisIRCcloud has quit IRC15:03
mithroDolu1990: I would be more than happy to send you an Arty A7 board16:44
mithroDolu1990: You have competition - :-)16:47
tpbTitle: Import the Taiga high performance RISC-V core · Issue #177 · enjoy-digital/litex · GitHub (at
Dolu1990mithro: Thanks :) I didn't knew about TAIGA, i'm looking at it right now :D17:03
mithroDolu1990: I think you beat them currently - but the student working on it is *super* smart, so watch out :-)17:03
Dolu1990There is much good features in their softcore ^.^17:04
mithroDolu1990: They are aiming for 2+ DMIPs/MHz17:07
mithroDolu1990: You should check out their paper from FCCM on an alternative way to do divide17:08
mithroRethinking Integer Divider Design for FPGA-based Soft Processors- Eric Matthews, Alec Lu, Lesley Shannon and Zhenman Fang17:09
mithroDolu1990: Send me a postal address + phone number to [email protected] and I'll get you an Arty A7 board17:09
Dolu1990It there more ressources than about taiga ?17:42
Dolu1990* Is there *17:42
_florent__mithro: thanks for taiga, i'll look at that18:13
_florent__mithro: btw, somlo should also have Rocket working soon18:14
_florent__mithro: if you want to do demo at Latchup of Linux with VexRiscv  and have an Arty, the only thing you have to do with the repo is ./ --flash :)18:15
mithro_florent__: Need a monitor or something to connect to it18:16
mithroDolu1990: Sadly I haven't found much apart from their repository18:16
somlo_florent__, mithro: once I figure out how to talk to the Rocket PLIC to correctly handle interrupts, I think it will be ready19:07
* somlo keeps fingers crossed (famous last words) :D19:08
Dolu1990Thanks :)19:23
Dolu1990In case of, I will be in the Zurich WOSH + RISC-V member day.19:24
*** Dolu1942 has joined #litex20:23
*** Dolu1990 has quit IRC20:26
mithrosomlo: Why do you care about rocket?21:00
mithroDolu1942: Do you have any spartan 6 hardware?21:03
Dolu1942Only ICE40[UP], Cyclone V21:05
somlomithro: I want to run an upstream standard (except maybe for peripheral dev drivers) kernel, and a "real" distro like Fedora or Debian22:31
somlomithro: basically, lowRISC except without the proprietary IP blocks from Vivado :)22:32
somloand without Vivado, while we're at it22:33
mithrosomlo: We should be in a place to do something like that on VexRISCV or Taiga soon....22:38
*** futarisIRCcloud has joined #litex23:02
futarisIRCcloudDolu1990: tinyfpga_ EX is supposed to have the 12F and HyperRAM. Not sure how much cheaper the BOM would be with SDRAM.23:05
Dolu1942hyper ram is only 8 MB of ram right ?23:07
futarisIRCcloudsomlo: If you add the required float and double stuff to the machine mode emulator, a generic 32 bit Linux kernel should run.23:07
futarisIRCcloud8MB on the PMOD hyperram board. Not sure if bigger chips are available. Uses a lot less pins than SDRAM.23:08
futarisIRCcloudAbout eleven years ago, I was fiddling with MaverickCrunch, and looking to implement soft-divide, on a processor that had hard float multiply:23:10
tpbTitle: 'Division using FMAC, reciprocal estimates and Newton-Raphson - eg ia64, rs6000, SSE, ARM Maverick' - MARC (at
daveshahWill probably be a few months time but the BlackEdge will have an ECP5 with DDR223:10
tpbTitle: The BlackEdge project - Announcements - myStorm (at
daveshahProbably 16MB for the 12k and 128MB for the 45k23:10
Dolu1942about SDRAM-SDR i have seen some chips for 2$23:12
daveshahYeah DDR2 pricing is similar23:12
daveshah128MB for $3 one off23:13
futarisIRCclouddaveshah: I'm surprised PaulStoffregen of teensy hasn't announced something yet. Isn't he based near where is?23:24
futarisIRCcloudmithro / xobs :
mithrofutarisIRCcloud: Paul is at latchup, I've meet him now :-)23:34
*** Dolu1990 has joined #litex23:35
*** Dolu1990 has quit IRC23:36
*** Dolu1942 has quit IRC23:38
futarisIRCcloudmithro: Cool. If only Sam Zeloof was there too.
mithroOh cool ->
tpbTitle: GitHub - wavedrom/verilog: wavedrom to verilog converter (at
futarisIRCcloudGood for unit tests.23:51

Generated by 2.13.1 by Marius Gedminas - find it at!