fwts snap: missing hint that --devmode is needed to access ACPI tables

[Heinrich Schuchardt]

I am running the fwts V23.11.00 2023-11-29 (909) on a RISC-V Ubuntu Mantic as root in directory /root.

acpidump shows several tables:

# acpidump | grep '^\S'
MCFG @ 0x0000000000000000
APIC @ 0x0000000000000000
DSDT @ 0x0000000000000000
FACP @ 0x0000000000000000
RHCT @ 0x0000000000000000

/snap/bin/fwts -a results in

acpidump: Dump ACPI tables.
--------------------------------------------------------------------------------
Test 1 of 1: Dump ACPI tables.
Cannot find any ACPI tables.

When I use the deb package with /usr/bin/fwts -a

acpidump: Dump ACPI tables.
--------------------------------------------------------------------------------
Test 1 of 1: Dump ACPI tables.
APIC @ bff00000 (672 bytes) (loaded from file)
----
[000h 0000 004h] Signature : "APIC" [Multiple APIC Description Table (MADT)]
[004h 0004 004h] Table Length : 000002A0
[008h 0008 001h] Revision : 06
[009h 0009 001h] Checksum : DC

Shouldn't the snap be able to access the same tables?

[Colin Ian King (colin-king)]

I believe to access the tables the snap version of fwts needs to be install using the --devmode snap install option.

[Heinrich Schuchardt (xypron)]

Hello Colin,

thanks for the hint. Installing snap fwts with --devmode resolves the issue.

We should add this information to the text displayed by snap info fwts and write a similar hint into results.log if reading ACPI tables fails. Environment variable $SNAP could be used to detect that fwts is running as snap.

Best regards

Heinrich

[Ivan Hu (ivan.hu)]

Hi Heinrich,

Please refer to fwts wiki, https://wiki.ubuntu.com/FirmwareTestSuite

I had added the install in devmode for fwts snap on this Tuesday.

[Heinrich Schuchardt (xypron)]

Hello Ivan,

thanks for adding that bit to the wiki.

A user looking at https://snapcraft.io/fwts or running snap info fwts cannot be expected to know that the wiki exists and that --devmode is essential.

Wouldn't it be a more user friendly approach to set confinement=classic in snapcraft.yaml instead of relying on users knowing about the devmode switch? Cf. https://snapcraft.io/docs/snap-confinement.

Best regards

Heinrich

[Colin Ian King (colin-king)]

Historical context:

The original snap issue was that there were a limited set of snap interfaces allowing access to various ACPI tables and system related data, so --devmode was the only solution. The interfaces may have improved since the original snapcraft yaml file was created, so classic mode may be (eventually) doable. I implemented the original snapcraft file, but I left Canonical 2+ years ago, so I've not kept up to date with the support of snap interfaces.

[Colin Ian King (colin-king)]

Fix pull requested: https://github.com/ColinIanKing/fwts/pull/15

[Heinrich Schuchardt (xypron)]

"confinement: devmode" can be specified in snapcraft.yaml.

[Colin Ian King (colin-king)]

I'll leave that to the fwts maintainer to fix and update :-)

[Ivan Hu (ivan.hu)]

Patch has been sent to fwts-devel,

https://lists.ubuntu.com/archives/fwts-devel/2023-December/013780.html

[Ivan Hu (ivan.hu)]

Released in fwts 24.01.00