Ping? I kinda realize it is not going to replace SLOF any time soon but still...
On 07/07/2020 10:34, Alexey Kardashevskiy wrote: > Ping? > > > On 24/06/2020 10:28, Alexey Kardashevskiy wrote: >> Ping? >> >> On 02/06/2020 21:40, Alexey Kardashevskiy wrote: >>> Ping? >>> >>> On 13/05/2020 13:58, Alexey Kardashevskiy wrote: >>>> The PAPR platform which describes an OS environment that's presented by >>>> a combination of a hypervisor and firmware. The features it specifies >>>> require collaboration between the firmware and the hypervisor. >>>> >>>> Since the beginning, the runtime component of the firmware (RTAS) has >>>> been implemented as a 20 byte shim which simply forwards it to >>>> a hypercall implemented in qemu. The boot time firmware component is >>>> SLOF - but a build that's specific to qemu, and has always needed to be >>>> updated in sync with it. Even though we've managed to limit the amount >>>> of runtime communication we need between qemu and SLOF, there's some, >>>> and it has become increasingly awkward to handle as we've implemented >>>> new features. >>>> >>>> This implements a boot time OF client interface (CI) which is >>>> enabled by a new "x-vof" pseries machine option (stands for "Virtual Open >>>> Firmware). When enabled, QEMU implements the custom H_OF_CLIENT hcall >>>> which implements Open Firmware Client Interface (OF CI). This allows >>>> using a smaller stateless firmware which does not have to manage >>>> the device tree. >>>> >>>> The new "vof.bin" firmware image is included with source code under >>>> pc-bios/. It also includes RTAS blob. >>>> >>>> This implements a handful of CI methods just to get -kernel/-initrd >>>> working. In particular, this implements the device tree fetching and >>>> simple memory allocator - "claim" (an OF CI memory allocator) and updates >>>> "/memory@0/available" to report the client about available memory. >>>> >>>> This implements changing some device tree properties which we know how >>>> to deal with, the rest is ignored. To allow changes, this skips >>>> fdt_pack() when x-vof=on as not packing the blob leaves some room for >>>> appending. >>>> >>>> In absence of SLOF, this assigns phandles to device tree nodes to make >>>> device tree traversing work. >>>> >>>> When x-vof=on, this adds "/chosen" every time QEMU (re)builds a tree. >>>> >>>> This adds basic instances support which are managed by a hash map >>>> ihandle -> [phandle]. >>>> >>>> Before the guest started, the used memory is: >>>> 0..4000 - the initial firmware >>>> 10000..180000 - stack >>>> >>>> This OF CI does not implement "interpret". >>>> >>>> With this basic support, this can only boot into kernel directly. >>>> However this is just enough for the petitboot kernel and initradmdisk to >>>> boot from any possible source. Note this requires reasonably recent guest >>>> kernel with: >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df5be5be8735 >>>> >>>> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> >>>> --- >>>> -- Alexey
