With LinuxBoot Linux relied on the legacy method of fetching the RSDP
pointer to get ACPI. This uses a more modern approach available since
2018 on the Linux kernel, which involves filling in the zero page.
This method takes precedence over any other method of fetching the
RSDP in Linux (UEFI, Kexec, Legacy/BIOS). Some UEFI zealots are
threatening that legacy code will be removed from Linux so it's best
to already adapt to that possibility.
Tested on Qemu:
- With qemu the RSDP is always in the EBDA, so checking if Linux uses
the provided pointer is better done with a forced bad entry
- With a fake bad pointer Linux correctly does not find RDSP
Change-Id: I688b94608b03b0177c42d2834c7e3beb802ae686
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62574
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
The e820 type don't fully match the LB_TAG_MEMORY types, so change all
unknown types to e820 to '2', reserved memory.
TESTED with Linuxboot: e820 now shows the CBMEM region as reserved.
Change-Id: Ie0e41c66e002919e41590327afe0f543e0037369
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55074
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Reviewed-by: Rocky Phagura
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
We have the git history which is a more reliable librarian.
Change-Id: Idbcc5ceeb33804204e56d62491cb58146f7c9f37
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41175
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: ron minnich <rminnich@gmail.com>
The linux trampoline was modifying the existing GDT
to add the 0x10 and 0x18 descriptors for Linux.
This will not work when the existing GDT is in ROM.
Change the code to set up a new GDT in what we know to be
RAM.
Tested by booting a linux payload. The main reason this works
is that Linux almost immediately loads its own GDT and then
segment registers. This GDT is a very temporary bridge.
Note that none of this change used to be necessary; the coreboot
GDT was originally compatible with Linux (ca 2000);
then Linux changed.
Change-Id: I13990052fbfd6a500adab8a2db8f7aead1d24fa6
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/27529
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Add the code necessary to create the linux trampoline blob.
Don't enforce this for the in-coreboot build or use objcopy
to produce linux_trampoline.o as it is a bit trickier to get
all the details right than I had hoped:
- you have to know the elf architecture of the host machine
- you might have to have more tools (xxd, perl, etc) installed
Change-Id: I9b7877c58d90f9fb21d16e0061a31e19fffa2470
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/12505
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Arthur Heymans