[meta-intel] [PATCH RFC] systemd-boot_%.bbappend: Add stub command line modifications patch

[Patrick Ohly]

On Wed, 2017-06-14 at 18:47 -0700, California Sullivan wrote:
> Allows you to modify the command line when called from EFI shell
> instead of the entire command line getting replaced.
> 
> Signed-off-by: California Sullivan <california.l.sullivan at intel.com>
> ---
> I liked this idea so I gave it a shot. Let me know what you think.
> Commit message is a WIP. Its getting late but I'd like some feedback.
> 
>  ...ub-allow-smarter-command-line-modificatio.patch | 132 +++++++++++++++++++++
>  .../systemd-boot/systemd-boot_%.bbappend           |   1 +
>  2 files changed, 133 insertions(+)
>  create mode 100644 common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
> 
> diff --git a/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch b/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
> new file mode 100644
> index 0000000..9cc92c9
> --- /dev/null
> +++ b/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
> @@ -0,0 +1,132 @@
> +From 47a4ce351911625f227b8b29d9c307d5c32fd32f Mon Sep 17 00:00:00 2001
> +From: California Sullivan <california.l.sullivan at intel.com>
> +Date: Wed, 14 Jun 2017 17:33:30 -0700
> +Subject: [PATCH] boot: efi: stub: allow smarter command line modifications
> +
> +Currently, the command line is replaced with anything that ends up in
> +LoadOptions. LoadOptions gets populated by the firmware, and EFI shell
> +command line information when running a binary. This includes the name
> +of the binary itself, so it will usually break booting from the EFI
> +shell.
> +
> +Instead, have LoadOptions modify the command line in the following way:
> +
> +bootx64 root=/dev/sda -> prepend the command line (default)
> +bootx64 ^console=/dev/tty0 -> prepend the command line (explicit)
> +bootx64 $console=/dev/tty0 -> append the command line
> +bootx64 !console=/dev/tty0 root=/dev/sda -> replace the command line
> +
> +The '^', '$' and '!' characters act as sentinel values, telling the EFI
> +stub how to handle LoadOptions values, as well as indicating where
> +command line modifications in LoadOptions should begin.
> +
> +Note that with the default case, bootx64 will end up in the kernel
> +command line, as we use the sentinel values to decide where to begin the
> +command line modifications.

As I was the one who proposed the syntax above, I should refrain from
commenting on it ;-} Someone else should say "yay" or "nay".

Regarding the code, I think this is something that should be submitted
upstream once we agree that we want this. The code review and perhaps
even merging can happen upstream.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.