On Mon, Jan 8, 2018 at 9:22 PM, Richard Wilbur <richard.wil...@gmail.com> wrote:
> One downside of the 2.7.4 board at this point is the changes in capacitor > pricing that have been ameliorated only on version 2.7.5. Here's hoping the > 2.7.5 board works! darn yeah i'd forgotten about the implications of the price-hike. whoops. > […] >> software-wise i need something that does nothing more complex than >> mount stuff on a micro-sd card, show boot messages on both screens, >> and maybe has 2 keyboards plugged in (one into each USB socket) so >> that they can bash some keys and see that crud comes up on-screen for >> each. >> >> going beyond that... testing I2C, UART and the GPIO.... *sigh*... >> that involves writing some software. > > I'd be happy to write some test software for I2C, UART, GPIO, etc. > I've worked on drivers for those interfaces on embedded machines in the past. > I also have experience creating and implementing software and hardware test > designs. One example, I modified my employer's PCI VGA BIOS to test the card > at boot which significantly streamlined testing of our cards. Another > example, > in order to test a design I created I2C driver and test code to demonstrate > feasibility > on a prototype and then incorporated it into production code in the BIOS and > driver. nice! well, this would be a lot simple: scan the I2C bus (lmsensors debian package), see if a peripheral at address 0x51 comes up, if it does _great_. it's a few lines of shell script. UART: if i add a USB-to-UART adapter onto a "test" microdesktop unit, if there's output on the console and it's not garbage, that's good enough. the GPIO... yes, that's where some coding comes in. there's actually only a few pins spare, they're all on the 14-pin header of the microdesktop board. except for two which are intended for bit-banging a separate I2C driver for VGA "EDID" detection.... > Happy to collaborate on board bring up as well. great. > I've worked on bringing up in-house boards for two employers: > PCI graphics cards (for which we used oscilloscope and completed someone > else's programmable logic design), embedded computers in different modules > of high-speed wireless communications links (tools used: spectrum analyzer, > oscilloscope, logic analyzer, PCI bus analyzer, MPEG protocol analysis > software, processor In-Circuit Emulator, serial terminal). ooo fuuun :) honestly the board's pretty "mature" and a lot simpler than that. no PCI, no PCIe, it's all SD/MMC, UART, USB, I2C, SPI, RGB/TTL, that sort of thing, where all of those have all worked in previous boards, no reason why they shouldn't work in the 2.7.5 version (except i tidied up the USB lines a bit... never keen on altering stuff that works... ah well). on the actual board itself, it's so tightly integrated (and also quite simple) that it tends to be an all-or-nothing. does power work, measure the voltages, yes no. ok does plugging in USB-OTG only have it show up on "lsusb" yes no. yes ok great let's load the FEL, does _that_ work, yes no, yes ok great, now does loading u-boot directly into DDR3 RAM work, yes, no. the FEL (u-boot-spl) loader has a nice debug feature of displaying a few lines of early UART. so that's a really good way to tell if the A20's alive. from there i can compile u-boot to look for a particular micro-sd card slot, which it will scan, and show debug messages "SD card detected" and so on. i can do commands which list the partitions and so on. it's pretty straghtforward: anything not working shows up really quickly and easily. > If you've got that covered, I'm happy playing the role of the ally > you can describe the problem to and who, through listening to > your description, helps you see the solution! appreciated. ... y'know... when we get to the RISC-V 64-bit SoC then that's going to be a lot trickier. aside from anything it will be necessary to do the DDR3 layout from scratch. i can't stand doing DDR3 layouts, they're... blegh :) get it wrong and yeah you reaaaly need a logic analyzer... oh. i have an RK3288 board that could use your help. i only got one of the DDR3 lanes up and running. l. _______________________________________________ arm-netbook mailing list arm-netbook@lists.phcomp.co.uk http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to arm-netb...@files.phcomp.co.uk
