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raspberrypi / firmware

This repository contains pre-compiled binaries of the current Raspberry Pi kernel and modules, userspace libraries, and bootloader/GPU firmware.
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Raspberry5 mailformed TFTP ACK packets #1898

Open zentarim opened 3 weeks ago

zentarim commented 3 weeks ago

At netboot, a Raspberry5 board sends malformed UDP packets padded with zeros while pulling resources from the TFTP server. As it may be seen in the raspberry5_ack_pad.pcapng.gz, a Raspberry 5 may acknowledge a TFTP data packet with ACK being padded with zeros. While it does not affect the boot process because the UDP length field is set to correct length, it is still an incorrect bootloader behavior.

raspberry5_ack.pcapng.gz

Filter: tftp.opcode == 4

That behavior has never happened with Raspberry 4 boards.

zentarim commented 3 weeks ago

I forgot to mention that both Raspberry4 and Raspberry5 share the same boot environment (DHCP, TFTP, etc)