[PATCH 0/4] Add pmem node for preserving distro ISO's

[Heinrich Schuchardt]

On 10/25/24 13:14, Sughosh Ganu 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.

Are you planning to provide the missing ACPI code for U-Boot?
QEMU provides ACPI tables which U-Boot passes through.
The x86 boards also need ACPI support.

Best regards

Heinrich

>
> 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.
>
>
>
> 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 (1):
>    efi: add helper functions to insert pmem node for DT fixup
>
>   boot/fdt_support.c           | 41 +++++++++++++++++++++++++++--
>   boot/image-fdt.c             |  9 +++++++
>   include/efi_loader.h         | 28 +++++++++++++++++---
>   include/fdt_support.h        | 13 +++++++++
>   lib/efi_loader/efi_bootmgr.c | 43 ++++++++++++++++++++++++++----
>   lib/efi_loader/efi_helper.c  | 12 +++++++++
>   lib/efi_loader/efi_memory.c  | 51 +++++++++++++++++++++++++++---------
>   lib/lmb.c                    |  4 +--
>   8 files changed, 175 insertions(+), 26 deletions(-)
>