Re: port-i386/56956: i386/pxeboot: cannot load netbsd kernel larger than 32 MiB with TFTP

[mlelstv%serpens.de@localhost (Michael van Elst)]

The following reply was made to PR port-i386/56956; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: port-i386/56956: i386/pxeboot: cannot load netbsd kernel larger than 32 MiB with TFTP
Date: Sun, 7 Aug 2022 06:17:44 -0000 (UTC)

 wataash%wataash.com@localhost writes:
 
 >    PXE BIOS Version 2.1
 >    Using PCI device at bus 0 device 3 function 0
 >    Ethernet address 52:54:00:ff:08:00
 >    28306576+1562064+535088read section headers: Unknown error: code 60
 >    boot: Input/output error
 >    Boot fai
 
 >This happens when x86 machine receives TFTP data block 65536. Instead of
 >replying the ack, the machine shows the error above.
 
 
 That's a limitation of the TFTP protocol.
 
 You could try to extend this a little bit with the TFTP blocksize
 option, but that's not necessarily supported by all TFTP servers.
 
 The standalone library (libsa) also doesn't support IP fragmentation
 (it doesn't even validate the ip_off field), on Ethernet (with 1500 byte frames)
  you could at most double the blocksize and thus the maximum file size.
 
 It might be more versatile to support other protocols to fetch a
 kernel.
 
 Another workaround might be to compress the kernel with gzip.