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authorRonald G. Minnich <rminnich@gmail.com>2019-10-22 02:02:24 +0000
committerron minnich <rminnich@gmail.com>2020-02-08 18:57:36 +0000
commit466ca2c1adbf2fc97dd559a3b69fcf0c7fe5d472 (patch)
tree24c665b13fe23e8e6be540ef917d1c23ad175309 /src/Kconfig
parent91dc1e74a52ec33dc7f5c33dca73f02c5fe54cf0 (diff)
downloadcoreboot-466ca2c1adbf2fc97dd559a3b69fcf0c7fe5d472.tar.xz
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/Kconfig')
-rw-r--r--src/Kconfig15
1 files changed, 15 insertions, 0 deletions
diff --git a/src/Kconfig b/src/Kconfig
index f538a1cc18..3742c04675 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -354,6 +354,21 @@ config RAMPAYLOAD
Skip PCI enumeration logic and only allocate BAR for fixed devices
(bootable devices, TPM over GSPI).
+config CONFIGURABLE_RAMSTAGE
+ bool "Enable a configurable ramstage."
+ default y if ARCH_X86
+ help
+ A configurable ramstage allows you to select which parts of the ramstage
+ to run. Currently, we can only select a minimal PCI scanning step.
+ The minimal PCI scanning will only check those parts that are enabled
+ in the devicetree.cb. By convention none of those devices should be bridges.
+
+config MINIMAL_PCI_SCANNING
+ bool "Enable minimal PCI scanning"
+ depends on CONFIGURABLE_RAMSTAGE
+ help
+ If this option is enabled, coreboot will scan only devices
+ marked as mandatory in devicetree.cb
endmenu
menu "Mainboard"