Hi Gregor, On Fri, 2025-11-14 at 00:38 +0100, Gregor Riepl wrote: > > I think the problem was that the generated kernel image is compressed which > > is why it > > won't work with GRUB unless to decompress it first on the target machine. > > Huh, you're right! > > At first glance, I thought there was a build option for this. > And there is, in fact, but it gets autoremoved if you try to set it on > sparc64. > This thread[1] hints that setting HAVE_KERNEL_UNCOMPRESSED helps, so I added > "select HAVE_KERNEL_UNCOMPRESSED=y" to arch/sparc/Kconfig helped, but this > didn't work. > I still ended up with a gzip-compressed /boot/vmlinuz. :(
I think powerpc doesn't build a compressed kernel by default, so it should be possible do set this as default for sparc as well. I just didn't have the time to work on this yet. > But no worries, decompressing it manually isn't a big deal. Yeah, but the problem is that some people don't know this and wonder why GRUB fails to boot the kernel. > > > apt install gcc-sparc64-linux-gnu libdw-dev:native libssl-dev:sparc64 > > > > What's libssl-dev needed for? > I have no idea... the build process seems to use some Debian functionality, > and it complains if the package isn't installed. > Oh, and I forgot... you still need to force cross-compilation, but you can > use the Debian compiler instead: > > export CROSS_COMPILE=sparc64-linux-gnu- > export ARCH=sparc > > And I can confirm that the resulting kernel boots fine. Good. > However... I can't seem to get KGDB to work. :( > This kernel has it enabled: > grep KGDB .config > CONFIG_HAVE_ARCH_KGDB=y > CONFIG_KGDB=y > CONFIG_KGDB_HONOUR_BLOCKLIST=y > CONFIG_KGDB_SERIAL_CONSOLE=y > # CONFIG_KGDB_TESTS is not set > CONFIG_KGDB_KDB=y > > But when I try to configure it, I get: > echo ttyS0 > /sys/module/kgdboc/parameters/kgdboc > bash: echo: write error: No such device > > Configuring through the kernel command line doesn't work either. > > The only KGDB-related message I see in dmesg is: > platform kgdboc: deferred probe pending: (reason unknown) > > Any ideas? I don't have any experience with KGDB, sorry. Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
