UEFI boot and sanhook

[parthy]

What I am trying to do is:

- Hook iSCSI disk in iPXE (the disk contains an EFI-installed Windows 10)
- Load a small multiboot-compliant kernel (in my case, Multiboot2, using this branch)
- In this kernel, I want to chainload the boot loader installed on the iSCSI disk without understanding iSCSI

On legacy systems, this was possible with this config:

Code:

# iscsi setup variables
sanhook --drive 0x80 ${root-path}
kernel tftp://${next-server}/my-boot-loader

The bootloader could then access the iSCSI disk via int13h, because iPXE emulates the BIOS calls.

Now I am trying to apply the same logic to UEFI. My understanding is that this should work because iPXE registers the iSCSI disk as a block device. As I wrote in my update, I got it working in the shell by using the snponly variant.

In the multiboot case, the first attempt to read anything from the disk just hangs. It looks like when the kernel is loaded, the network connection is cut.

It also works now with the multiboot kernel if I remove the shutdown_boot() call, in this line.

Somehow there must be a difference to legacy systems when it comes to this shutdown call.

I hope this makes it a bit clearer.