How to patch the latest version of start.elf?

[iosoft]

Hello,

How to patch the latest version of start.elf?

Pls help us out.
Thanks.

[rapi3]

in /boot/start.elf and /boot/start_x.elf
search for 47E933363248
after this hex string:
if you have 3C18 replace 18 with 1F
if you have 1D18 replace 18 with 1F

[alexschultze]

YOU are the man!

I tried and diff'ed for several hours. This just works fine. (OpenELEC).
Please commit this to the README otherwise other people will waste time as well.

[rapi3]

Thanks.
Forked and added info at top of page.

[Ristovski]

@rapi3 Could you open a pull request?
Edit: Ideally one that just updates the old patch instead of adding a new section for the "latest version"

[jamesy0ung]

Has anyone tried this on Pi4/CM4?

[mbirth]

To quote their page:

On the Raspberry Pi 4, the hardware codecs for MPEG2 or VC1 are permanently disabled and cannot be enabled even with a licence key; on the Pi 4, thanks to its increased processing power compared to earlier models, MPEG2 and VC1 can be decoded in software via applications such as VLC. Therefore, a hardware codec licence key is not needed if you're using a Pi 4.

[iosoft]

in /boot/start.elf and /boot/start_x.elf
search for 47E933363248
after this hex string:
if you have 3C18 replace 18 with 1F
if you have 1D18 replace 18 with 1F

what tool to use?

[kiam001]

patch dont work on 19.06,2021

[infojoe]

Last version this works on is Apr-15-2020:
https://github.com/raspberrypi/firmware/tree/9e3c23ce779e8cf44c33d6a25bba249319207f68/boot

The latest files all show the following after the 47E933363248 string:

start.elf: 0918
start_x.elf: has two locations, 0090 and 1D18

Hopefully someone smarter than me will be able to make it work.

[Ristovski]

I wanted to try patching the latest binaries but sadly the IDA Pro plugin for VideoCore III/IV is outdated and only works on the quite old IDA 6 which I currently do not have.

Even more unfortunately, neither Ghidra nor radare2/rizin seem to have a VideoCore plugin either, so I am unable to look into this.

Might look into hunting down an old IDA version some time next week just to take a look, but no promises.

[z4tracer]

Last version this works on is Apr-15-2020: https://github.com/raspberrypi/firmware/tree/9e3c23ce779e8cf44c33d6a25bba249319207f68/boot

The latest files all show the following after the 47E933363248 string:

start.elf: 0918 start_x.elf: has two locations, 0090 and 1D18

Hopefully someone smarter than me will be able to make it work.

I'm trying to check this method with my rpi2 / rpi3 with Libreelec, still works.
However OSMC is not working.

[rapi3]

check my fork I updated patch for latest version 2022:
LibreELEC (community): nightly-20220212-d9a07e9 (RPi2.arm)
LE-rpi33:~ # vcgencmd codec_enabled MPG2
MPG2=enabled
LE-rpi33:~ # vcgencmd codec_enabled WVC1
WVC1=enabled

https://github.com/rapi3/raspi-keygen

[csgabe]

You can use bbe to patch binary files:
https://linux.die.net/man/1/bbe