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Failed to connect to MySQL: (1203) User howardkn already has more than 'max_user_connections' active connectionsPath: ...!weretis.net!feeder9.news.weretis.net!3.eu.feeder.erje.net!2.eu.feeder.erje.net!feeder.erje.net!newsfeed.bofh.team!paganini.bofh.team!not-for-mail From: antispam@fricas.org (Waldek Hebisch) Newsgroups: comp.lang.forth Subject: Re: 1 euro Olimex RISC-V mini-PC: this needs Forth ;) Date: Thu, 17 Oct 2024 15:28:13 -0000 (UTC) Organization: To protect and to server Message-ID: References: <87frpoewse.fsf@nightsong.com> <5c2cb38df0180a4dce21ed5c01a8f0d3@www.novabbs.com> <874j5ycd68.fsf@nightsong.com> <87zfnqawwi.fsf@nightsong.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Thu, 17 Oct 2024 15:28:13 -0000 (UTC) Injection-Info: paganini.bofh.team; logging-data="1417223"; posting-host="WwiNTD3IIceGeoS5hCc4+A.user.paganini.bofh.team"; mail-complaints-to="usenet@bofh.team"; posting-account="9dIQLXBM7WM9KzA+yjdR4A"; User-Agent: tin/2.6.2-20221225 ("Pittyvaich") (Linux/6.1.0-9-amd64 (x86_64)) X-Notice: Filtered by postfilter v. 0.9.3 Bytes: 5462 Lines: 89 Paul Rubin wrote: > zbigniew2011@gmail.com (LIT) writes: >> There are numerous videos about it on YT, from what I see — just >> search for 'MILKV'. > > I looked at the milkv web site a bit more, and it looks nice. I see the > 256MB version in the $15 range on aliexpress. The 64MB version is > harder to buy in the US. And, I have no idea how well the software > works on either version. I ordered 3 kinds: 64Mb, 256Mb and Milkv-Duo-S (this has 512 Mb). Linux images fetched from Github boot fine and simple things work. This is very minimal Linux, on 64Mb board I get: [root@milkv-duo]~# cat /proc/cpuinfo processor : 0 hart : 0 isa : rv64imafdvcsu mmu : sv39 [root@milkv-duo]~# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 770048 177105 549526 25% / devtmpfs 14408 0 14408 0% /dev tmpfs 14484 0 14484 0% /dev/shm tmpfs 14484 48 14436 1% /tmp tmpfs 14484 28 14456 1% /run /dev/mmcblk0p1 130798 3226 127572 3% /boot [root@milkv-duo]~# free total used free shared buff/cache available Mem: 28972 14496 4148 76 10328 11720 Swap: 0 0 0 As you can see Linux take 177Mb of disc space. There is no compiler (and even no assembler) and available utilities are quite limited. This is probably intended to be a Python board, Python takes about 75 Mb of disc space. But 64Mb version may be short on memory for Python. For example [root@milkv-duo]~# pip3 list Killed Apparently this tried to use 13Mb and triggered oom-kill. On 64Mb board memory available to Linux is limited as 29Mb is reserved mainly for media purposes (apparently one needs to rebuild disc image to change memory allocation). I my short trial I met two glitches. On Milkv-Duo-S 'poweroff' instead of turning off the board causes reboot (on 64Mb board 'poweroff' works fine). This is known problem at least for few months. The second trouble is that they propose to use USB networking (CDC-NCM). This works fine with one of my desktop machines, but fails with other. Since in both cases I use the same Milkv board the trouble seem to be on Linux side (possibly a security limitation). But they write "it just works". On Milkv-Duo-S is also tried to connect Ethernet, it worked fine. It seems that developement for those board is supposed to be done by cross compilation. There seem to be considerable fragmentation of Risc-V ecosystem. First, there are many possible subsets. IIUC 'rv64imafd' is supposed to be reasonably sane base and the board support more: 'rv64imafdvcsu' which IIUC adds compressed instructions, vestor extention and some systmem (priviledged extention). Provided Linux uses 'musl'. On desktop machine I fetched Debian cross compiler for Risc-V, it is based on 'glibc'. ATM I managed to cross-compile statically linked hello world, after copying to the board it worked fine (but executable is 491kb). I also cross-assembled assembly version, this one is 1480b. So, cross-assembling or cross compiling some Forth should not be very hard. ATM I am thinking about good use case for 64Mb board. Nice thing is low power use. When board is "doing nothing" (more precisly board is blinking the blue LED and I am logged in via USB network) my USB power meter shows 0 (it is certainly not 0 but almost surely less than 50mA), with CPU-intensive job on Linux core I see 70mA power draw. So powerwise it is probably competitive with Cortex-M processors. OTOH main justification for Linux boards is networking and having real web server. But the 64-Mb board (and 256-Mb board) needs external Ethernet transformer and connector, in principle nothing hard, but practically it will add cost and make it less convenient. I must admit that Duo-S which has Ethernet connector looks more attractive to me, despite costing twice as much as 64Mb board. AFAICS the Risc-V developement tools are extremally bloated. Source for the Linux image is about 4.5Gb, toolchain sources about 6.8Gb. -- Waldek Hebisch