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 V3: * Rephrased the 2MiB alignment error message as suggested by Heinrich * Rephrased the description of fdt_fixup_pmem_region() function as suggested by Heinrich * Add the map type to the blkmap slice instead of the entire blkmap device * Move the definition of the helper function to the efi_helper.c * Remove the region of the blkmap mem map device from the EFI memory map along with adding the pmem node 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 slice in corresponding structure blkmap: add pmem nodes for blkmap memory mapped slices boot/fdt_support.c | 41 ++++++++++++++++- boot/image-fdt.c | 9 ++++ drivers/block/blkmap.c | 82 +-------------------------------- include/blkmap.h | 87 ++++++++++++++++++++++++++++++++++++ include/efi.h | 13 ++++++ include/efi_loader.h | 11 +++-- include/fdt_support.h | 14 ++++++ lib/efi_loader/efi_bootmgr.c | 22 ++++++--- lib/efi_loader/efi_helper.c | 52 +++++++++++++++++++++ lib/efi_loader/efi_memory.c | 51 +++++++++++++++------ lib/lmb.c | 4 +- 11 files changed, 281 insertions(+), 105 deletions(-) -- 2.34.1
