From 15901164ee71dec0906dadaff08f3365a66feb05 Mon Sep 17 00:00:00 2001 From: Scott Rifenbark Date: Tue, 18 Jul 2017 10:44:37 -0700 Subject: dev-manual, ref-manual: Eliminated pre-built section Fixes [YOCTO #11630] I took the section that described how to use a pre-built kernel and run it through QEMU out. This is basically a QEMU usage section and is not in that area. There were some QEMU speed up items suitable for the QEMU concepts section in the ref-manual. I put those in that area. (From yocto-docs rev: b081013aa10b42e4eb88ed54940112c5ae106911) Signed-off-by: Scott Rifenbark Signed-off-by: Richard Purdie --- documentation/ref-manual/usingpoky.xml | 78 ++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) (limited to 'documentation/ref-manual') diff --git a/documentation/ref-manual/usingpoky.xml b/documentation/ref-manual/usingpoky.xml index 2f5316d54b..c323d38318 100644 --- a/documentation/ref-manual/usingpoky.xml +++ b/documentation/ref-manual/usingpoky.xml @@ -1111,6 +1111,84 @@ +
+ QEMU Performance + + + Using QEMU to emulate your hardware can result in speed issues + depending on the target and host architecture mix. + For example, using the qemux86 image in the + emulator on an Intel-based 32-bit (x86) host machine is fast + because the target and host architectures match. + On the other hand, using the qemuarm image + on the same Intel-based host can be slower. + But, you still achieve faithful emulation of ARM-specific issues. + + + + To speed things up, the QEMU images support using + distcc to call a cross-compiler outside the + emulated system. + If you used runqemu to start QEMU, and the + distccd application is present on the host + system, any BitBake cross-compiling toolchain available from the + build system is automatically used from within QEMU simply by + calling distcc. + You can accomplish this by defining the cross-compiler variable + (e.g. export CC="distcc"). + Alternatively, if you are using a suitable SDK image or the + appropriate stand-alone toolchain is present, the toolchain is + also automatically used. + + + + Several mechanisms exist that let you connect to the system + running on the QEMU emulator: + + + QEMU provides a framebuffer interface that makes standard + consoles available. + + + Generally, headless embedded devices have a serial port. + If so, you can configure the operating system of the + running image to use that port to run a console. + The connection uses standard IP networking. + + + SSH servers exist in some QEMU images. + The core-image-sato QEMU image has a + Dropbear secure shell (SSH) server that runs with the root + password disabled. + The core-image-full-cmdline and + core-image-lsb QEMU images + have OpenSSH instead of Dropbear. + Including these SSH servers allow you to use standard + ssh and scp + commands. + The core-image-minimal QEMU image, + however, contains no SSH server. + + + You can use a provided, user-space NFS server to boot + the QEMU session using a local copy of the root + filesystem on the host. + In order to make this connection, you must extract a + root filesystem tarball by using the + runqemu-extract-sdk command. + After running the command, you must then point the + runqemu + script to the extracted directory instead of a root + filesystem image file. + See the + "Running Under a Network File System (NFS) Server" + section in the Yocto Project Development Manual for more + information. + + + +
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QEMU Command-Line Syntax -- cgit v1.2.3-54-g00ecf