From 8877dd0eeaada2010410c16a6300c0e7f6ed75ba Mon Sep 17 00:00:00 2001 From: Liav A Date: Sun, 19 Dec 2021 21:41:39 +0200 Subject: Base: Update boot_parameters(7) to describe the enable_ioapic option The document describes the implications of enabling and disabling that option on the ability to enable SMP mode, and describes the requirements for enabling IOAPIC mode even without enabling SMP mode. --- Base/usr/share/man/man7/boot_parameters.md | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'Base') diff --git a/Base/usr/share/man/man7/boot_parameters.md b/Base/usr/share/man/man7/boot_parameters.md index d9c2e6d342..f38a06038d 100644 --- a/Base/usr/share/man/man7/boot_parameters.md +++ b/Base/usr/share/man/man7/boot_parameters.md @@ -35,6 +35,12 @@ List of options: * **`disable_virtio`** - If present on the command line, virtio devices will not be detected, and initialized on boot. +* **`enable_ioapic`** - This parameter expects **`on`** or **`off`** and is by default set to **`on`**. + When set to **`off`**, the kernel will initialize the two i8259 PICs. + When set to **`on`**, the kernel will try to initialize the IOAPIC (or IOAPICs if there's more than one), + but only if **`acpi`** is set to **`limited`** or **`on`**, and a `MADT` (APIC) table is available. + Otherwise, the kernel will fallback to use the i8259 PICs. + * **`fbdev`** - This parameter expects **`on`** or **`off`**. * **`force_pio`** - If present on the command line, the IDE controllers will be force into PIO mode when initialized IDE Channels on boot. @@ -53,11 +59,12 @@ List of options: * **`pci_ecam`** - This parameter expects **`on`** or **`off`**. * **`root`** - This parameter configures the device to use as the root file system. It defaults to **`/dev/hda`** if unspecified. - + * **`smp`** - This parameter expects a binary value of **`on`** or **`off`**. If enabled kernel will - use [APIC](https://en.wikipedia.org/wiki/Advanced_Programmable_Interrupt_Controller) mode - for handling interrupts instead of [PIC](https://en.wikipedia.org/wiki/Programmable_interrupt_controller) mode. - This parameter defaults to **`off`**. + enable available APs (application processors) and use them with the BSP (Bootstrap processor) to + schedule and run threads. + This parameter defaults to **`off`**. This parameter requires **`enable_ioapic`** to be enabled + and and a `MADT` (APIC) table to be available. * **`system_mode`** - This parameter is not interpreted by the Kernel, and is made available at `/proc/system_mode`. SystemServer uses it to select the set of services that should be started. Common values are: - **`graphical`** (default) - Boots the system in the normal graphical mode. -- cgit v1.2.3