Date: Tue, 16 Aug 2022 11:44:53 +0200 From: Guido van Rooij <guido@gvr.org> To: Warner Losh <imp@bsdimp.com> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: How to use serial console to enter GELI password to boot kernel on a GELI encrypted ZFS pool Message-ID: <YvtnFeFc/vmXnPcx@gvr.gvr.org> In-Reply-To: <CANCZdfoR9TcF71O0O7K2KT-_hsDG_6kxKK9KHpHdoowCoS709g@mail.gmail.com> References: <YvpW59mY6eK5KOQ0@gvr.gvr.org> <CANCZdfoR9TcF71O0O7K2KT-_hsDG_6kxKK9KHpHdoowCoS709g@mail.gmail.com>
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On Mon, Aug 15, 2022 at 02:20:32PM -0600, Warner Losh wrote:
> On Mon, Aug 15, 2022 at 8:23 AM Guido van Rooij <[1]guido@gvr.org>
> wrote:
>
> Currently I have a system with ZFS on GELI. I use the ability in
> the EFI loader to enter the GELI password.
> Is it possible somehow to use a serial console to enter the
> password?
> My system does have a COM1 port but it isn't recognised at the early
> bot stage. There I only see:
> Â Â Consoles: EFI console
> Â Â GELI Passphrase for disk0p4:
> (Note: this is early in the boot process so there is no access to
> boot.config (or any other file in the ZFS pool) as it still on
> encrypted storage at that time).
>
> The boot loader.efi will read ESP:/efi/freebsd/loader.env for
> environment
> variables. You can use that to set the COM1 port since it appears your
> EFI system doesn't do console redirection.
> If you want it to only prompt COM1 for the password, but everything
> else is
> on the efi console, that's a lot harder.
Hi Warner,
Thanks, but somehow I still cannot get it to work properly.
Content of /efi/freebsd/loader.env:
boot_multicons="YES"
console="efi comconsole"
The boot prompt still only shows "Consoles: EFI console".
When I boot I get the GELI passphrase prompt at the EFI console only. But when the kernel starts
to run I do get output to the serial console, staring with:
---<<BOOT>>---
Copyright (c) 1992-2021 The FreeBSD Project.
So it seems the loader.env file is read correctly (it didn't output anything to the serial
console before I created efi/freebsd/loader.env). But looking at the source I see in
efi/loader/main.c:read_loader_env():
if (fn) {
printf(" Reading loader env vars from %s\n", fn);
parse_loader_efi_config(boot_img->DeviceHandle, fn);
}
I never saw the printf appearing. I do not understand this.
Hope you can help me further!
Regards,
-Guido
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