On Fri, 24 Jan 2025 at 17:10, Ilias Apalodimas <ilias.apalodi...@linaro.org> wrote: > > Heinrich, Tobias > > There's a slight problem that I forgot when commenting v2. > > Heinrich's idea of plugging this into blkmap is eventually the right > thing to do. > > However, when I started coding this I only added the pmem memory as > 'reserved' in the DT hoping that would work. > Unfortunately, this depends on a kernel config option. I've managed to > track down the problem here[0], but I haven't found time to test it > properly and send it upstream. > So for this feature to work reliably we *need* to remove the memory > map we hand over to the OS. > > Since using EFI memmap function into the blkmap code makes no sense, > can we perhaps merge v2 (or a variant of it), which only targets EFI, > with an explanation of *why* while I try to sort out the kernel issue?
If it has been decided to go with the approach taken in V2, I will send an updated series which incorporates the other nits that Heinrich had on the patches. Those were handled in this version. -sughosh > > > [0] https://git.linaro.org/people/ilias.apalodimas/net-next.git/commit/?h=main > > Thanks > /Ilias > > On Mon, 20 Jan 2025 at 12:51, Sughosh Ganu <sughosh.g...@linaro.org> wrote: > > > > > > When installing a distro via EFI HTTP boot some OS installers expect > > the .iso image to be preserved and treat it as a "CDROM" to install > > packages. > > > > This is problematic in EFI, since U-Boot mounts the image, starts the > > installer, and eventually calls ExitBootServices. At that point the > > image U-Boot mounted disappears. Some distros don't care and download > > the missing packages from a web archive, while others halt the > > installation complaining they can't find certain packages. > > > > If the firmware uses ACPI, this is supported by using NFIT which > > provides NVDIMM ramdisks to the OS and preserves the image. > > We don't have anything in place for Device Trees though. Since DT > > supports persistent memory nodes (pmem) use those and preserve the > > .iso for installers. > > > > The issue can be reproduced by attempting an EFI HTTP boot with Ubuntu > > live server ISO, or a Rocky Linux ISO. The installation would fail > > with the failure to locate certain packages. > > > > The earlier version had aligned the addition of pmem nodes with the > > EFI HTTP boot feature. This has been changed, based on a review > > comment from Heinrich to instead be done by looping through the memory > > based blkmamp devices. > > > > Changes since V2: > > * Fix a checkpatch error for putting a blank line after a function > > * Use blkmap device based scanning for adding the pmem nodes > > > > > > > > Ilias Apalodimas (2): > > efi_loader: add a function to remove memory from the EFI map > > efi_loader: preserve installer images in pmem > > > > Masahisa Kojima (1): > > fdt: add support for adding pmem nodes > > > > Sughosh Ganu (2): > > blkmap: store type of blkmap device in corresponding structure > > blkmap: add pmem nodes for blkmap mem mapping devices > > > > boot/fdt_support.c | 40 ++++++++++++- > > boot/image-fdt.c | 9 +++ > > cmd/blkmap.c | 16 ++++-- > > drivers/block/blkmap.c | 90 +++-------------------------- > > drivers/block/blkmap_helper.c | 47 +++++++++++++++- > > include/blkmap.h | 103 +++++++++++++++++++++++++++++++++- > > include/efi_loader.h | 11 ++-- > > include/fdt_support.h | 13 +++++ > > lib/efi_loader/efi_bootmgr.c | 22 ++++++-- > > lib/efi_loader/efi_memory.c | 51 ++++++++++++----- > > lib/lmb.c | 4 +- > > test/dm/blkmap.c | 16 +++--- > > 12 files changed, 302 insertions(+), 120 deletions(-) > > > > -- > > 2.34.1 > > > >
