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| author | Ronald G. Minnich <rminnich@gmail.com> | 2019-10-22 02:02:24 +0000 |
|---|---|---|
| committer | ron minnich <rminnich@gmail.com> | 2020-02-08 18:57:36 +0000 |
| commit | 466ca2c1adbf2fc97dd559a3b69fcf0c7fe5d472 (patch) | |
| tree | 24c665b13fe23e8e6be540ef917d1c23ad175309 /src/mainboard/emulation | |
| parent | 91dc1e74a52ec33dc7f5c33dca73f02c5fe54cf0 (diff) | |
Add configurable ramstage support for minimal PCI scanning
This CL has changes that allow us to enable a configurable
ramstage, and one change that allows us to minimize PCI
scanning. Minimal scanning is a frequently requested feature.
To enable it, we add two new variables to src/Kconfig
CONFIGURABLE_RAMSTAGE
is the overall variable controlling other options for minimizing the
ramstage.
MINIMAL_PCI_SCANNING is how we indicate we wish to enable minimal
PCI scanning.
Some devices must be scanned in all cases, such as 0:0.0.
To indicate which devices we must scan, we add a new mandatory
keyword to sconfig
It is used in place of on, off, or hidden, and indicates
a device is enabled and mandatory. Mandatory
devices are always scanned. When MINIMAL_PCI_SCANNING is enabled,
ONLY mandatory devices are scanned.
We further add support in src/device/pci_device.c to manage
both MINIMAL_PCI_SCANNING and mandatory devices.
Finally, to show how this works in practice, we add mandatory
keywords to 3 devices on the qemu-q35.
TEST=
1. This is tested and working on the qemu-q35 target.
2. On CML-Hatch
Before CL:
Total Boot time: ~685ms
After CL:
Total Boot time: ~615ms
Change-Id: I2073d9f8e9297c2b02530821ebb634ea2a5c758e
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36221
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jeremy Soller <jeremy@system76.com>
Diffstat (limited to 'src/mainboard/emulation')
| -rw-r--r-- | src/mainboard/emulation/qemu-q35/devicetree.cb | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/mainboard/emulation/qemu-q35/devicetree.cb b/src/mainboard/emulation/qemu-q35/devicetree.cb index 671a2d631d..c032606e67 100644 --- a/src/mainboard/emulation/qemu-q35/devicetree.cb +++ b/src/mainboard/emulation/qemu-q35/devicetree.cb @@ -5,10 +5,10 @@ chip mainboard/emulation/qemu-q35 end end device domain 0 on - device pci 0.0 on end # northbridge (q35) + device pci 0.0 mandatory end # northbridge (q35) chip southbridge/intel/i82801ix # present unconditionally - device pci 1f.0 on end # LPC + device pci 1f.0 mandatory end # LPC device pci 1f.2 on end # SATA device pci 1f.3 on end # SMBus |