--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Thu, Jan 19, 2023 at 9:06 AM Andreas Grapentin <[email protected]> wrote: > > > > > On 18. Jan 2023, at 14:54, Luke Kenneth Casson Leighton <[email protected]> > > wrote: > > > > On Tuesday, January 17, 2023, Andreas Grapentin <[email protected] > > <mailto:[email protected]>> > > wrote: > >> > >> U-Boot SPL 2013.07-07841-g569c37da7d-dirty (Jan 17 2023 - 19:37:10) > >> Board: EOMA68_A20 > >> DRAM: 1024 MiB > >> CPU: 960000000Hz, AXI/AHB/APB: 3/2/2 > >> SUNXI SD/MMC: 0 > > > > okaay the SPL loader will now be trying to look on sd/mmc 0 > > for a u-boot image. clearly it is not finding it. > > From looking at the sunxi spl code, this is the enumeration of all detected > mmc slots, > not the configured one. It would be good to compare the output to a known > good board. ah - right. then you may have an earlier revision of the EOMA68-A20 which does indeed have sd/mmc 0 attached to the micro-sd socket. in which case the advised build instructions - which are for the *newer* EOMA68-A20 - will obviously not work. > I started looking at the micro desktop board with my multimeter and did some > checks, but it’s difficult without reference to a known good board. But what > is maybe noteworthy is that of the three larger capacitors on the board just > behind the power socket, both sides of all of them are connected to ground. that's a serious short, yes, if the resistance between them is zero (or close to it). check the 5v rail. > I assume that part of the board is responsible for the power control? 7-22v down to 5v, yes. > I’ve noticed that the boot loops above are pretty random — > it might be possible I’m not supplying enough power to the microsd slot, > I’ll try to use a stronger power supply. that would be unwise as it will cause further burnouts due to the short. > Otherwise, I’m pretty certain I’m using the correct microsd slot, because > configuring any other slot in boards.cfg results in timeout errors in the MMC > code, which leads to the reported error -1 you are better off powering from USB-OTG entirely bypassing the MD or removing the RT8288 entirely from the PCB. the problem with not using the MD is you have to insert wires directly into the EOMA68-A20 tx/rx and GND holes. done that before, it was a pain-in-the-ass but it worked. you do NOT need power because they are open-drain. l. _______________________________________________ arm-netbook mailing list [email protected] Configuration, options, subscribe and unsubscribe at: http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to: [email protected]
