| Message ID | alpine.DEB.2.10.1905011628310.23881@sstabellini-ThinkPad-X260 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/arm: improve dom0less documentation | expand |
Hi Stefano, On 5/2/19 12:30 AM, Stefano Stabellini wrote: > Improve Dom0-less documentation: include a complete configuration > example. > > Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> > > diff --git a/docs/features/dom0less.pandoc b/docs/features/dom0less.pandoc > index 4e342b7..e076e37 100644 > --- a/docs/features/dom0less.pandoc > +++ b/docs/features/dom0less.pandoc The content is probably ok features, although I am worry of duplication with docs/misc/arm/device-tree/booting.txt. However, when looking how other features deal with similar description, I noticed that we don't follow the template (see templates.pandoc). I am aware this is a suggestion, but it would be good to follow it as a user would be able to find his way through it more easily and would help to know this is Arm only (this is not clearly spell out). Could you have a look at it? This could be a follow-up so: Acked-by: Julien Grall <julien.grall@arm.com> Cheers,
On 12/06/2019 19:59, Julien Grall wrote: > Hi Stefano, > > On 5/2/19 12:30 AM, Stefano Stabellini wrote: >> Improve Dom0-less documentation: include a complete configuration >> example. >> >> Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> >> >> diff --git a/docs/features/dom0less.pandoc b/docs/features/dom0less.pandoc >> index 4e342b7..e076e37 100644 >> --- a/docs/features/dom0less.pandoc >> +++ b/docs/features/dom0less.pandoc > > The content is probably ok features, although I am worry of duplication with > docs/misc/arm/device-tree/booting.txt. > > However, when looking how other features deal with similar description, > I noticed that we don't follow the template (see templates.pandoc). > > I am aware this is a suggestion, but it would be good to follow it as a user > would be able to find his way through it more easily and would help to know this > is Arm only (this is not clearly spell out). > > Could you have a look at it? > > This could be a follow-up so: > > Acked-by: Julien Grall <julien.grall@arm.com> Now committed. Thank you! Cheers,
On Fri, 14 Jun 2019, Julien Grall wrote: > On 12/06/2019 19:59, Julien Grall wrote: > > Hi Stefano, > > > > On 5/2/19 12:30 AM, Stefano Stabellini wrote: > > > Improve Dom0-less documentation: include a complete configuration > > > example. > > > > > > Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> > > > > > > diff --git a/docs/features/dom0less.pandoc b/docs/features/dom0less.pandoc > > > index 4e342b7..e076e37 100644 > > > --- a/docs/features/dom0less.pandoc > > > +++ b/docs/features/dom0less.pandoc > > > > The content is probably ok features, although I am worry of duplication with > > docs/misc/arm/device-tree/booting.txt. > > > > However, when looking how other features deal with similar description, > > I noticed that we don't follow the template (see templates.pandoc). > > > > I am aware this is a suggestion, but it would be good to follow it as a user > > would be able to find his way through it more easily and would help to know > > this is Arm only (this is not clearly spell out). > > > > Could you have a look at it? > > > > This could be a follow-up so: > > > > Acked-by: Julien Grall <julien.grall@arm.com> > > Now committed. > > Thank you! Thanks!
diff --git a/docs/features/dom0less.pandoc b/docs/features/dom0less.pandoc index 4e342b7..e076e37 100644 --- a/docs/features/dom0less.pandoc +++ b/docs/features/dom0less.pandoc @@ -23,6 +23,70 @@ booted and the Xen tools to become available, domains created by Xen this way are started right away in parallel. Hence, their boot time is typically much shorter. + +Configuration +------------- + +### Loading binaries into memory ### + +U-Boot needs to load not just Xen, the device tree binary, the dom0 kernel and +ramdisk. It also needs to load the kernel and ramdisk of any additional domains +to boot. For example if this is the bootcmd for Xen and Dom0: + + tftpb 0x1280000 xen.dtb + tftpb 0x0x80000 xen-Image + tftpb 0x1400000 xen.ub + tftpb 0x9000000 xen-rootfs.cpio.gz.u-boot + + bootm 0x1400000 0x9000000 0x1280000 + +If we want to add one DomU with Image-DomU as the DomU kernel +and ramdisk-DomU as DomU ramdisk: + + tftpb 0x1280000 xen.dtb + tftpb 0x80000 xen-Image + tftpb 0x1400000 xen.ub + tftpb 0x9000000 xen-rootfs.cpio.gz.u-boot + + tftpb 0x2000000 Image-DomU + tftpb 0x3000000 ramdisk-DomU + + bootm 0x1400000 0x9000000 0x1280000 + + +### Device Tree configuration ### + +In addition to loading the necessary binaries, we also need to advertise +the presence of the additional VM and its configuration. It is done via +device tree adding a node under /chosen as follows: + + domU1 { + compatible = "xen,domain"; + memory = <0x20000>; + cpus = 1; + vpl011; + + module@2000000 { + compatible = "multiboot,kernel", "multiboot,module"; + reg = <0x2000000 0xffffff>; + bootargs = "console=ttyAMA0"; + }; + + module@30000000 { + compatible = "multiboot,ramdisk", "multiboot,module"; + reg = <0x3000000 0xffffff>; + }; + }; + +Where memory is the memory of the VM in KBs, cpus is the number of +cpus. module@2000000 and module@3000000 advertise where the kernel and +ramdisk are in memory. + +See docs/misc/arm/device-tree/booting.txt for more information. + +Limitations +----------- + Domains started by Xen at boot time currently have the following limitations:
Improve Dom0-less documentation: include a complete configuration example. Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>