Go to advanced search

by timg236
Thu Jul 18, 2019 6:50 pm
Forum: General discussion
Topic: Pi 4 WiFi Troubles
Replies: 1
Views: 30

Re: Pi 4 WiFi Troubles

Please can you check the output of dmesg to see if there are any Wi-fi or SDIO messages.
It might also be useful to know what channels the access point is using and whether it’s 5ghz
by timg236
Thu Jul 18, 2019 3:07 pm
Forum: General discussion
Topic: RPi 4 : Lost GPIO-3 restart (and fix)
Replies: 21
Views: 1196

Re: RPi 4 : Lost GPIO-3 restart (and fix)

Unless we find any serious problems in the next few days the next version of the bootloader will default to WAKE_ON_GPIO=1. The main reason is that it's not possible to turn of 5V because the the board can be powered via the 5V pin and some HATS don't like having 5V but no 3V3. The halt power off ca...
by timg236
Thu Jul 18, 2019 10:38 am
Forum: Advanced users
Topic: Updated bootloader for Pi4
Replies: 13
Views: 490

Re: Updated bootloader for Pi4

Conceptually it's the same as the bootcode in the Pi3 ROM, it's just possible to fix stuff after manufacture But something executing autonomously could erase-write it, or parts of it, far more frequently, and one likely only needs to make the smallest part of the Eeprom unusable to bring everything...
by timg236
Thu Jul 18, 2019 8:11 am
Forum: HATs and other add-ons
Topic: Pi4 bootloader update / change to halt behaviour
Replies: 0
Views: 47

Pi4 bootloader update / change to halt behaviour

Apologises for the cross-post but the updated Pi4 bootloader might be of interest to anyone working on HATS. During HALT the default behaviour will be low power mode where 3V3 remains on. It's possible to revert to the previous power-off of the PMIC via an EEPROM config setting https://www.raspberry...
by timg236
Thu Jul 18, 2019 6:24 am
Forum: Advanced users
Topic: Updated bootloader for Pi4
Replies: 13
Views: 490

Re: Updated bootloader for Pi4

If you reflash your bootrom 100k times, you are doing something wrong. Or something else is. I was idly wondering how quickly one could brick someone else's Pi for them - not that I have any intention of doing so. About an hour I reckon. Though erase-cycles are often conservatively stated so it cou...
by timg236
Wed Jul 17, 2019 7:56 pm
Forum: Advanced users
Topic: Updated bootloader for Pi4
Replies: 13
Views: 490

Re: Updated bootloader for Pi4

There's a 'safe mode' recovery which will allow basic booting from sd-card to allow for a transaction but that's not ready just yet. Is rescuing oneself from an erased / corrupted Bootloader Eeprom not covered by booting an SD Card with the SPI Bootloader Eeprom Recovery files on it ? https://www.r...
by timg236
Wed Jul 17, 2019 7:43 pm
Forum: Advanced users
Topic: Disable all boot text in Buster
Replies: 6
Views: 360

Re: Disable all boot text in Buster

It's a bit fiddly but for an internal test we did this on a buildroot image so something similar should work in a Buster image on Pi4

The workaround was to completely disable tty1 in inittab as well as quiet etc

sed -i "s,^tty1::respawn:.*$,," ${TARGET_DIR}/etc/inittab
by timg236
Wed Jul 17, 2019 4:30 pm
Forum: Advanced users
Topic: Updated bootloader for Pi4
Replies: 13
Views: 490

Re: Updated bootloader for Pi4

Reflashed the RPi 4 boards I've got and looks to be working here. Is there going to be an easier procedure for updating in the future or is this it? e.g. it'll start booting instead of just rapidly blinking the LED once it has updated the EEPROM. Just wondering as an update process that doesn't req...
by timg236
Wed Jul 17, 2019 3:44 pm
Forum: Advanced users
Topic: Updated bootloader for Pi4
Replies: 13
Views: 490

Updated bootloader for Pi4

There's a new release candidate image for the Raspberry Pi4 bootloader - see https://www.raspberrypi.org/forums/viewtopic.php?f=117&t=246027 This might be of interest to anyone implementing 'power off' buttons or HATS but should be invisible to most users. Feel free to post any bug reports on this t...
by timg236
Tue Jul 16, 2019 4:59 pm
Forum: Advanced users
Topic: How can I overclock Raspberry PI 4 GPU/core/video core to more then 600MHz?
Replies: 8
Views: 465

Re: How can I overclock Raspberry PI 4 GPU/core/video core to more then 600MHz?

nice to know, but why is this not included in the dedicated page? https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md where should i find other informations? hdmi_blanking and sd_overclock also seems to be not working is "over_voltage_sdram" supported? will sdram over...
by timg236
Tue Jul 16, 2019 2:19 pm
Forum: Advanced users
Topic: How can I overclock Raspberry PI 4 GPU/core/video core to more then 600MHz?
Replies: 8
Views: 465

Re: How can I overclock Raspberry PI 4 GPU/core/video core to more then 600MHz?

sdram overclock: i can set it from 3200 to 3600 but i can't see any real difference :?: The SDRAM frequency for Pi4 is fixed at boot and the only supported value for the data rate is sdram_freq is 3200 (*), other values are ignored. Above this then the bus infrastructure will be the limiting factor...
by timg236
Sun Jul 14, 2019 11:18 am
Forum: Troubleshooting
Topic: Extremly Poor performance with tvout enabled
Replies: 11
Views: 428

Re: Extremly Poor performance with tvout enabled

IIRC there was a problem with the launch firmware where vsync updates were not getting through to FKMS for tvout. This caused the boot to be very slow because every screen updated timed out. If you can run dmesg then there should be evidence of this in the logs

Not sure if this has been fixed though.
by timg236
Sun Jul 14, 2019 11:06 am
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 4
Replies: 42
Views: 3720

Re: Raspberry Pi 4

Is it the VC6 booting first on the Pi4? Does the Boot EEPROM use ARM or VC6 code? The VPU is the boot processor on Pi4. The ROM runs recovery.bin from the sd-card, if it exists for EEPROM repair, otherwise, it loads the EEPROM image. The ARM is initialised by start.elf and you can supply your own A...
by timg236
Sat Jul 13, 2019 10:17 pm
Forum: General discussion
Topic: New rpi4 issues with 4k
Replies: 12
Views: 812

Re: New rpi4 issues with 4k

Sorry, the changes apply to a file called /boot/config.txt. Make a backup first but none of these settings are dangerous. Comment out the fkms line and add the other values to the [rpi4] section. But yes, I'm saying tell the firmware what the preferred resolution is in order to force it to allocate ...
by timg236
Sat Jul 13, 2019 7:41 pm
Forum: General discussion
Topic: New rpi4 issues with 4k
Replies: 12
Views: 812

Re: New rpi4 issues with 4k

It's not very elegant but applying theses changes to config.txt should force the legacy framebuffer to run at 4K. No idea how well VNC will support this though. There's some improvements in the pipeline for forcing display modes with FKMS enabled. #dtoverlay=vc4-fkms-v3d hdmi_group=1 # Fake 4Kp30 hd...
by timg236
Fri Jul 12, 2019 7:31 am
Forum: HATs and other add-ons
Topic: PoE hat, Raspberry Pi 4, not able to power off
Replies: 39
Views: 1732

Re: PoE hat, Raspberry Pi 4, not able to power off

If you have a USB UART cable then it would be interesting to get the bootloader debug output during the reboot. It prints the value of the reset register. To enable logging download the bootloader update from https://www.raspberrypi.org/downloads/ sed -i -e "s/BOOT_UART=0/BOOT_UART=1/" pieeprom.bin ...
by timg236
Wed Jul 10, 2019 8:26 pm
Forum: General discussion
Topic: Raspberry Pi 4 Dual Monitors
Replies: 39
Views: 2339

Re: Raspberry Pi 4 Dual Monitors

I did the rpi-update yesterday and the second monitor then workined fine. But after an 'apt update upgrade' the unit does not fully boot. I see the 4 Raspberries on the first monitor then blank screens and just the RED LED lit on the Pi4-4G board. If I remove the second monitor connection the boot ...
by timg236
Wed Jul 10, 2019 4:07 pm
Forum: General discussion
Topic: Raspberry Pi 4 usb boot?
Replies: 107
Views: 10432

Re: Raspberry Pi 4 usb boot?

Answering a few random questions The next boot mode will be PXE/network boot, then probably USB mass storage mode. We intend to post beta-images on the forums for new features. There's no plan for general purpose storage in the EEPROM, maybe a small number of settings that can be read back from Linu...
by timg236
Wed Jul 10, 2019 3:43 pm
Forum: General discussion
Topic: Raspberry Pi 4 can´t boot!
Replies: 12
Views: 448

Re: Raspberry Pi 4 can´t boot!

Please can you try booting without the sd-card present. If the green LED light flashes 4 times then EEPROM is running but indicating that start.elf is not found.

It's also worth checking that the boot partition is FAT16/FAT32 and not exFAT or NTFS.
by timg236
Mon Jul 08, 2019 11:51 am
Forum: General discussion
Topic: RPi 4 : Lost GPIO-3 restart (and fix)
Replies: 21
Views: 1196

Re: RPi 4 : Lost GPIO-3 restart

Wake on GPIO3 is still possible but will consume significantly more power than on Pi3. So, for Pi4 "halt" was implemented to power off the outputs from the PMIC with GLOBAL_EN used to wake up. For backwards compatibility with HATS you can can edit the bootloader's builtin mini config.txt file Downlo...
by timg236
Wed Jun 26, 2019 8:33 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 705
Views: 60651

Re: Raspberry Pi 4 Thread - general discussion

Yes, the firmware wasn't parsing the "YCbCr420_only" extended block of the EDID, so was seeing [email protected] in the detailed timings but then not filtering it out due to being YCbCr420 (which currently isn't supported). I understand - HDMI 2.0 can be a minefield... So currently what 4K60 (aka 2160p6...
by timg236
Wed Jun 26, 2019 7:44 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 705
Views: 60651

Re: Raspberry Pi 4 Thread - general discussion

I ran into a similar issue when testing LibreELEC on my LG 55C8 last week. 6by9 provided a last minute firmware fix that's included in LibreELEC but probably didn't make it into Raspbian. The fix should be included in lastest rpi-update firmware though. A simple workaround was to enable the "HDMI U...
by timg236
Tue Jun 25, 2019 12:52 pm
Forum: Bare metal, Assembly language
Topic: Pi 4B Bare Metal Videocore
Replies: 3
Views: 543

Re: Pi 4B Bare Metal Videocore

For Pi4 build the bare-metal project as an ELF file instead of a .bin file, you can than run whatever VPU code you like and SDRAM will be initialised :)

I'd recommend picking an address of 64MB or above because USB or PXE boot may choose to leave diagnostics in low memory.
by timg236
Tue Jun 25, 2019 12:18 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 Model B - SPI EEPROM Corruption/Recovery
Replies: 5
Views: 1217

Re: Raspberry Pi 4 Model B - SPI EEPROM Corruption/Recovery

One important consequence of this is that my oft-given assurance that an RPi board has no user-modifiable persistent memory and is thus always 'factory fresh' at every Power On is henceforth not accurate. On Pi3 it is possible to change the boot behaviour via OTP settings and this is required for P...
by timg236
Tue Jun 25, 2019 10:10 am
Forum: General discussion
Topic: Raspberry Pi 4 - Sleep Mode
Replies: 7
Views: 1194

Re: Raspberry Pi 4 - Sleep Mode

I had the same question. Just to be clear, are you saying that there is still no sleep mode for the Pi 4? Lack of a true sleep mode is what's prevented me from using a Pi for several applications over the last couple of years - it pretty much prevents battery-powered apps. Is there some endemic fea...

Go to advanced search