From 162a5284faf41b2441b8f686f9ac4771c7a8f669 Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Sun, 30 May 2021 12:24:45 -0400 Subject: [PATCH] x86/reboot: Document the "reboot=pci" option It is mentioned in the top level non-arch specific file but it was overlooked here for x86. Signed-off-by: Paul Gortmaker Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210530162447.996461-2-paul.gortmaker@windriver.com --- Documentation/x86/x86_64/boot-options.rst | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst index 5f62b3b86357..482f3b29f99a 100644 --- a/Documentation/x86/x86_64/boot-options.rst +++ b/Documentation/x86/x86_64/boot-options.rst @@ -126,7 +126,7 @@ Idle loop Rebooting ========= - reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] [, [w]arm | [c]old] + reboot=b[ios] | t[riple] | k[bd] | a[cpi] | e[fi] | p[ci] [, [w]arm | [c]old] bios Use the CPU reboot vector for warm reset warm @@ -145,6 +145,8 @@ Rebooting Use efi reset_system runtime service. If EFI is not configured or the EFI reset does not work, the reboot path attempts the reset using the keyboard controller. + pci + Use a write to the PCI config space register 0xcf9 to trigger reboot. Using warm reset will be much faster especially on big memory systems because the BIOS will not go through the memory check. -- 2.20.1