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Cbmem pci rb info#281

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miczyg1 wants to merge 11 commits intodasharofrom
cbmem_pci_rb_info
Open

Cbmem pci rb info#281
miczyg1 wants to merge 11 commits intodasharofrom
cbmem_pci_rb_info

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@miczyg1 miczyg1 commented Oct 22, 2025

Some fixes for Gigabyte MZ33-AR1 server to work.

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miczyg1 commented Oct 22, 2025

We can wait until upstream patches are merged, because we certainly don't want to have any conflicts with cbmem IDs

@miczyg1 miczyg1 force-pushed the cbmem_pci_rb_info branch 4 times, most recently from 238dc72 to 1309219 Compare November 5, 2025 15:55
@miczyg1 miczyg1 force-pushed the cbmem_pci_rb_info branch from 76b2b66 to 00374b8 Compare March 5, 2026 16:04
@miczyg1 miczyg1 force-pushed the cbmem_pci_rb_info branch 13 times, most recently from 60e4901 to d3e520c Compare March 25, 2026 13:20
@miczyg1 miczyg1 force-pushed the cbmem_pci_rb_info branch 9 times, most recently from 82cfd6d to 358f988 Compare April 16, 2026 11:49
miczyg1 added 10 commits April 16, 2026 13:50
On AMD server systems there are multiple PCI root bridges. The root
bridge scanning in UEFI Payload is not sufficient to detect the memory
and I/O apertures properly. For example, on Turin system, the I/O
aperture on the first root bridge containing the FCH may not have any
I/O resources detected on the PCI devices. This results in the I/O
decoding to be disabled on the root bridge, effectively breaking the
I/O-based serial ports, e.g. on Super I/Os and BMCs.

Populate the root bridge info from CB_TAG_RB_INFO which contains data
compatible with the Universal Payload PCI Root Bridges Info HOB. Make
the PciHostBridgeLib pick the HOB up, if available, and populate
proper root bridge apertures for AMD systems. Otherwise, fall back
to root bridge scanning.

Relevant coreboot patches:
https://review.coreboot.org/c/coreboot/+/89486
https://review.coreboot.org/c/coreboot/+/89487

TEST=Boot UEFI Payload and see the serial console no longer breaks
after PCI enumeration in UEFI Payload on Gigabyte MZ33-AR1.

Upstream-Status: Pending
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Mark the range 0x1000-0xa0000 as tested. It caused the payload to mark
this range as reserved. As a result, Linux kernel could not allocate
memory for real mode and panicked.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
There was a dirty hack for Intel platforms that read TOLUD register
to determine the boundary between MMIO and DRAM. It caused problems
on AMD platforms such as apu2, which does not have TOLUD register. As
a result, regions which held reserved memory were incorrectly
reported as RAM buffers or RAM itself and the OS allocated DMA there.
It could be observed with many IO_PAGE_FAULTs occurring in the OS.
See: Dasharo/dasharo-issues#1134

FWTS complains on ECAM MMCONF not being reserved in the memory map.
So carve it out of the memory map and report it as reserved.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
FWTS complains on MMCONF not being reseved in memory map. So reserve
it.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
…ve 4G RAM

Do not clear testd attribute from above 4G RAM memory. It caused the
payload to mark above 4G ranges as reserved. As a result, Linux kernel
had only as much memory, as there is available memory below 4G reported
by coreboot. It caused out of memory processes kills in Linux.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
…MMIO

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
coreboot always uses TSC for timestamps, force correct timer library
so measurements are accurate. A mismatch of timers will result in
incorrect tick and nanosecond calculations due to different timer
frequency.

Add a copy of BaseCpuTimerLib from UefiCpuPkg and replace TSC frequency
calculation with the value obtained from coreboot timestamp table.
On Intel systems where the UefiCpuPkg/CpuTimerLib is used, there is no
mismatch. However, AMD systems do not have the required CPUID, so the
default timer is HPET, not TSC.

TEST=Boot Gigabyte MZ33-AR1 and use systemd-analyze. The firmware boot
time is no longer 19 minutes, but indicates correct time spent in
firmware.

Upstream-Status: Pending
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
…ties

The timer/counter start and end value were hardcoded instead of being
read from the performance protocol.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
Print the 64bit SMMSTORE MMIO address if available. If the structure
length field indicates that 64bit MMIO address is present, it means
the 32bit MMIO address is deprecated and initialized to 0. To avoid
misinterpretation of debug logs, print the 64bit MMIO address to
indicate that SMMSTORE HOB has been created successfully and there
are no problems.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Upstream-Status: Pending
…read

Add an override from openSIL/amd-edk2-platforms repo for USB mass
storage. On Gigabyte MZ33-AR1 there are lots of errors from virtual
CD-ROM from BMC. These additional resets help a bit in USB enumeration
during boot.

Upstream-Status: Pending
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
@miczyg1 miczyg1 force-pushed the cbmem_pci_rb_info branch from 358f988 to af03924 Compare April 16, 2026 11:51
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miczyg1 commented Apr 16, 2026

@mkopec @SergiiDmytruk could you please review?

The PR is waiting for some time already and it will be needed for all AMD platforms to work properly. I would like to get it merged to start with Gigabyte MZ33-AR1 release.

AMD silicon has different definitions for SLP_Sx states written
to the ACPI PM register than Intel.

Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
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