On Mon, Aug 8, 2016 at 8:33 PM, james harvey <jamespharve...@gmail.com> wrote: > <<< How does booting through iPXE disrupt the BIOS E820 map? >>> > > Booting 4.6.4 from the Arch 2016.08.01 ISO on a DVD properly sees > 64GB. (See quote 1.) > > Booting the same ISO through iPXE only sees about 50*M*B usable, and > the detected memory map sections are reported as "BIOS-88" rather than > "BIOS-e820". (See quote 2.) I have seen discussions that say the > 0x88 BIOS memory function may limit reporting to 15MB, or sometimes up > to 64MB. > > This gives a kernel panic for "initrd too large to handle, disabling > initrd (27,426,236 needed, 26,398,720 available)" (commas added.) > > How would booting through iPXE disrupt kernel's ability to obtain the > BIOS-supplied E820 map? This is happening in > linux/arch/x86/kernel/e820.c::default_machine_specific_memory_setup(). > > What are my avenues forward? > > (... snip ...)
Resolved. Was hitting the card's CTRL+B hotkey during POST, since my BIOS wasn't recognizing it as a bootable device. Tracked down using iPXE debugging that the BIOS E820 function isn't available during the POST stage. Luckily for me, my motherboard released a BIOS update that partially fixes recognizing it as a bootable device in the past month or so, so I've been able to move past the issue.
