| Message ID | 20201105175153.30489-7-alex.bennee@linaro.org |
|---|---|
| State | Accepted |
| Commit | 0146037807831ff6424e5b8be66532ce39f0eb13 |
| Headers | show |
| Series | Xen guest-loader and arm64 build fixes/enhancements | expand |
On Thu, Nov 5, 2020 at 9:58 AM Alex Bennée <alex.bennee@linaro.org> wrote: > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > docs/system/guest-loader.rst | 54 ++++++++++++++++++++++++++++++++++++ > docs/system/index.rst | 1 + > 2 files changed, 55 insertions(+) > create mode 100644 docs/system/guest-loader.rst > > diff --git a/docs/system/guest-loader.rst b/docs/system/guest-loader.rst > new file mode 100644 > index 0000000000..37d03cbd89 > --- /dev/null > +++ b/docs/system/guest-loader.rst > @@ -0,0 +1,54 @@ > +.. > + Copyright (c) 2020, Linaro > + > +Guest Loader > +------------ > + > +The guest loader is similar to the `generic-loader` although it is > +aimed at a particular use case of loading hypervisor guests. This is > +useful for debugging hypervisors without having to jump through the > +hoops of firmware and boot-loaders. > + > +The guest loader does two things: > + > + - load blobs (kernels and initial ram disks) into memory > + - sets platform FDT data so hypervisors can find and boot them > + > +This is what is typically done by a boot-loader like grub using it's > +multi-boot capability. A typical example would look like: > + > +.. parsed-literal:: > + > + |qemu_system| -kernel ~/xen.git/xen/xen \ > + -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \ > + -device guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro console=hvc0 earlyprintk=xen" \ > + -device guest-loader,addr=0x47000000,initrd=rootfs.cpio > + > +In the above example the Xen hypervisor is loaded by the -kernel > +parameter and passed it's boot arguments via -append. The Dom0 guest > +is loaded into the areas of memory. Each blob will get > +`/chosen/module@<addr>` entry in the FDT to indicate it's location and > +size. Additional information can be passed with by using additional > +arguments. > + > +Currently the only supported machines which use FDT data to boot are > +the ARM and RiscV `virt` machines. RISC-V. Otherwise: Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Alistair > + > +Arguments > +^^^^^^^^^ > + > +The full syntax of the guest-loader is:: > + > + -device guest-loader,addr=<addr>[,kernel=<file>,[bootargs=<args>]][,initrd=<file>] > + > +``addr=<addr>`` > + This is mandatory and indicates the start address of the blob. > + > +``kernel|initrd=<file>`` > + Indicates the filename of the kernel or initrd blob. Both blobs will > + have the "multiboot,module" compatibility string as well as > + "multiboot,kernel" or "multiboot,ramdisk" as appropriate. > + > +``bootargs=<args>`` > + This is an optional field for kernel blobs which will pass command > + like via the `/chosen/module@<addr>/bootargs` node. > diff --git a/docs/system/index.rst b/docs/system/index.rst > index 3cff0ca98f..b5cfe8ee93 100644 > --- a/docs/system/index.rst > +++ b/docs/system/index.rst > @@ -25,6 +25,7 @@ Contents: > ivshmem > linuxboot > generic-loader > + guest-loader > vnc-security > tls > gdb > -- > 2.20.1 > >
On Thu, 19 Nov 2020 at 20:30, Alistair Francis <alistair23@gmail.com> wrote: > > On Thu, Nov 5, 2020 at 9:58 AM Alex Bennée <alex.bennee@linaro.org> wrote: > > +Currently the only supported machines which use FDT data to boot are > > +the ARM and RiscV `virt` machines. > > RISC-V. If we're going to be picky, also "Arm" :-) -- PMM
diff --git a/docs/system/guest-loader.rst b/docs/system/guest-loader.rst new file mode 100644 index 0000000000..37d03cbd89 --- /dev/null +++ b/docs/system/guest-loader.rst @@ -0,0 +1,54 @@ +.. + Copyright (c) 2020, Linaro + +Guest Loader +------------ + +The guest loader is similar to the `generic-loader` although it is +aimed at a particular use case of loading hypervisor guests. This is +useful for debugging hypervisors without having to jump through the +hoops of firmware and boot-loaders. + +The guest loader does two things: + + - load blobs (kernels and initial ram disks) into memory + - sets platform FDT data so hypervisors can find and boot them + +This is what is typically done by a boot-loader like grub using it's +multi-boot capability. A typical example would look like: + +.. parsed-literal:: + + |qemu_system| -kernel ~/xen.git/xen/xen \ + -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \ + -device guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro console=hvc0 earlyprintk=xen" \ + -device guest-loader,addr=0x47000000,initrd=rootfs.cpio + +In the above example the Xen hypervisor is loaded by the -kernel +parameter and passed it's boot arguments via -append. The Dom0 guest +is loaded into the areas of memory. Each blob will get +`/chosen/module@<addr>` entry in the FDT to indicate it's location and +size. Additional information can be passed with by using additional +arguments. + +Currently the only supported machines which use FDT data to boot are +the ARM and RiscV `virt` machines. + +Arguments +^^^^^^^^^ + +The full syntax of the guest-loader is:: + + -device guest-loader,addr=<addr>[,kernel=<file>,[bootargs=<args>]][,initrd=<file>] + +``addr=<addr>`` + This is mandatory and indicates the start address of the blob. + +``kernel|initrd=<file>`` + Indicates the filename of the kernel or initrd blob. Both blobs will + have the "multiboot,module" compatibility string as well as + "multiboot,kernel" or "multiboot,ramdisk" as appropriate. + +``bootargs=<args>`` + This is an optional field for kernel blobs which will pass command + like via the `/chosen/module@<addr>/bootargs` node. diff --git a/docs/system/index.rst b/docs/system/index.rst index 3cff0ca98f..b5cfe8ee93 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -25,6 +25,7 @@ Contents: ivshmem linuxboot generic-loader + guest-loader vnc-security tls gdb
Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- docs/system/guest-loader.rst | 54 ++++++++++++++++++++++++++++++++++++ docs/system/index.rst | 1 + 2 files changed, 55 insertions(+) create mode 100644 docs/system/guest-loader.rst