Go to advanced search

by Synoia
Fri Aug 09, 2019 5:34 pm
Forum: Networking and servers
Topic: Pi 4 - Dual Monitor Thinclient
Replies: 9
Views: 1514

Re: Pi 4 - Dual Monitor Thinclient

Have two identical Dell monitors Buster works well. Remmina, as thin MS Windows client does not. 1. Stretching the MS windows rdp session to both monitors moves the LHS of the MS windows RDP session information right. I've discussed this with the remmina people and they are looking at it. 2. Expandi...
by Synoia
Mon Sep 19, 2016 6:14 pm
Forum: Device Tree
Topic: device tree overlays and U-Boot
Replies: 32
Views: 13227

Re: device tree overlays and U-Boot

The Flattened Device Tree format, which is what is generated by dtc and stored in DTB files and overlays, starts with a header including the length: struct boot_param_header { u32 magic; /* magic word 0xd00dfeed */ u32 totalsize; /* total size of DT block */ u32 off_dt_struct; /* offset to structur...
by Synoia
Mon Sep 12, 2016 8:49 pm
Forum: Device Tree
Topic: device tree overlays and U-Boot
Replies: 32
Views: 13227

Re: device tree overlays and U-Boot

The DTB start address is size dependent. The aim is to copy the DTB as high as possible. Once the kernel starts it will "unflatten" the DTB into allocated memory and then re-use the space. 1 ARM memory starts at 0 in the VPU physical address space. The GPU memory sits at the top. This is how it wor...
by Synoia
Mon Sep 12, 2016 8:48 pm
Forum: Device Tree
Topic: device tree overlays and U-Boot
Replies: 32
Views: 13227

Re: device tree overlays and U-Boot

Has anyone found a way to view the u-boot output and kernel boot output over pins 14/15? I'm able to start u-boot without any problems but I can't see the kernel booting process over serial. I've tried merging the device tree files (bcm2710-rpi-3-b.dts and pi3-disable-bt-overlay.dts) and started th...
by Synoia
Mon Sep 12, 2016 8:46 pm
Forum: Device Tree
Topic: device tree overlays and U-Boot
Replies: 32
Views: 13227

Re: device tree overlays and U-Boot

How would u-boot discover the length of the device tree?
by Synoia
Wed Aug 10, 2016 5:56 pm
Forum: Advanced users
Topic: u-boot
Replies: 0
Views: 389

u-boot

We have u-boot booting all Raspbian from a debian file server. Only firmware and u-boot file are on the sdcard. However in the boot process the display resolution changes at kernel start time from the config.txt value to one with much less resolution. Setting the explicit display resolution and the ...
by Synoia
Mon Jun 06, 2016 9:18 pm
Forum: Advanced users
Topic: Under-voltage warnings
Replies: 209
Views: 332341

Re: Under-voltage warnings

I use a very short USB cable (about 1 ft) and the best power supply I can find.

2.1 A @ 5 V over a thin cable = voltage loss.

Go to advanced search