timg236
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 524
Joined: Thu Jun 21, 2018 4:30 pm

Re: Update to default Pi4 bootloader

Wed Jun 03, 2020 4:48 pm

You could try adding bootcode_delay in config.txt to delay for a few seconds before the bootloader attempts to loader start.elf

The other way of getting logs is NETCONSOLE which could be enabled on-demand via a GPIO filter

hippy
Posts: 7448
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

Re: Update to default Pi4 bootloader

Wed Jun 03, 2020 6:31 pm

Thanks for the suggestion "bootcode_delay" did nothing, "boot_delay" blanked the screen, put the monitor to sleep, then woke with the rainbow screen.

I had looked at NETCONSOLE as that would be the best option, but couldn't figure how to capture the packets. I thought I was capturing them in a Python program but there was no readable text. It's on my list of things to figure out.

lingon
Posts: 157
Joined: Fri Aug 26, 2011 7:31 am

Re: Update to default Pi4 bootloader

Wed Jun 03, 2020 7:00 pm

timg236 wrote:
Wed Jun 03, 2020 4:35 pm
lingon wrote:
Wed Jun 03, 2020 4:22 pm
The download problem was due to too strict cookie settings. I installed that release and the Raspberry Pi 4 cold boots and reboots fine with it from the eMMC module.

vcgencmd version
Jun 3 2020 13:08:21
Copyright (c) 2012 Broadcom
version b5de8c32f4f45a12a1fdfe107254df82965f9d56 (clean) (release) (start)

Is there anything else I could test?

Would it be possible to get the eMMC speed up to DDR50 from 22.98 MB/sec reported by hdparm?
Thanks for testing.

It would useful if you could test hdmi_enable_4kp60=1 or core_freq=550 in config.txt because that's slightly more slightly to trigger a race condition.

Bootloader / start.elf performance is unlikely to get any better until the drivers are written to use the new SDHCI controller on 2711 (instead of legacy Aransan EMMC). On Linux the driver should be running at full speed but IIRC the DMA only works in the bottom 1 gigabyte of memory so you could be hitting bounce buffers in that test.
I tested first with hdmi_enable_4kp60=1 and then with core_freq=550 both cold boots and reboots and it booted fine.

Booting with total_mem=1024 does not increase the reading speed of the eMMC module in the uSD-eMMC adapter.

The eMMC modules that I have can reach quite high speeds. The uSD-eMMC adapter I use is a purely passive device, so what I'm wondering is why the uSD-eMMC adaper with a eMMC module only reaches a reading speed of 23 MB/s, while a real uSD-card on a Raspberry Pi 4 reaches about 44 MB/s (DDR50).

So do you mean that the new 2711 SDHCI controller can reach a higher speed that DDR50?

timg236
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 524
Joined: Thu Jun 21, 2018 4:30 pm

Re: Update to default Pi4 bootloader

Wed Jun 03, 2020 7:09 pm

I was just referring to booting which is is a bit slower and uses the old controller. Once Linux is started the EMMC2 interface is used and it's the upstream driver which unfortunately I'm not familiar with.
I can't see an obvious reason why an eMMC module would be slower than uSD.

lingon
Posts: 157
Joined: Fri Aug 26, 2011 7:31 am

Re: Update to default Pi4 bootloader

Thu Jun 04, 2020 2:35 pm

timg236 wrote:
Wed Jun 03, 2020 12:29 pm

Please could you try this potential firmware fix? It's a from a dev branch and is otherwise untested so please backup the card first!

release-b5de8c32.zip
https://drive.google.com/drive/folders/ ... sp=sharing
I tried booting from the eMMC module with that release also on my older Raspberry Pi computers. I have also tried out the latest release version on the same computers. Unfortunately there is a regression concerning eMMC booting in both of these firmware versions.
I have been able to boot also a Raspberry Pi 3, Raspberry 2 and Raspberry Pi 1 256 MB from eMMC but none of these eMMC boot with these two firmware versions. What could be the reason for this?

vcgencmd version
Jun 1 2020 13:23:40
Copyright (c) 2012 Broadcom
version 6379679d1ec6a8c746d7e77e015f5b56b939976f (clean) (release) (start)

So far I have never been able to eMMC boot on a Raspberry Pi 1 B 512 MB and a Raspberry Pi A 256 MB.

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