From 06d83d2eb307ad927dc4b2f9f7269be7f6d5c754 Mon Sep 17 00:00:00 2001 From: Henry Wang Date: Mon, 15 Mar 2021 11:10:58 +0800 Subject: [PATCH] docs: device_model: Updated the serial device doc As we switched the AArch64 serial device to PL011, we also need to update the documentation. Signed-off-by: Henry Wang --- docs/device_model.md | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/docs/device_model.md b/docs/device_model.md index 33d6ea462..825365de6 100644 --- a/docs/device_model.md +++ b/docs/device_model.md @@ -28,9 +28,13 @@ This document describes the device model supported by `cloud-hypervisor`. ### Serial port Simple emulation of a serial port by reading and writing to specific port I/O -addresses. Used as the default console for Linux when booting with the option -`console=ttyS0`, the serial port can be very useful to gather early logs from -the operating system booted inside the VM. +addresses. The serial port can be very useful to gather early logs from the +operating system booted inside the VM. + +For x86_64, The default serial port is from an emulated 16550A device. It can +be used as the default console for Linux when booting with the option +`console=ttyS0`. For AArch64, the default serial port is from an emulated +PL011 UART device. The related command line for AArch64 is `console=ttyAMA0`. This device is always built-in, and it is disabled by default. It can be enabled with the `--serial` option, as long as its parameter is not `off`.