asmc: add Wake-on-LAN control via sysctl

[seuros]

Summary

Apple Mac systems support Wake-on-LAN from powered-off state (S5/G2) via the AUPO SMC key.

This change adds a convenience sysctl:

dev.asmc.0.wol (0=disabled, 1=enabled)

The AUPO key is volatile and resets to 0x00 on every boot, so WoL must be manually enabled before each shutdown to work from powered-off state.
Users need to run:
sysctl dev.asmc.0.wol=1
before shutting down the system.

Test Plan

Tested on Mac Mini 5,1 (FreeBSD 16.0-CURRENT):

1. Boot system, check default WoL state:

• sysctl dev.asmc.0.wol
• Expected: 0 (disabled - AUPO resets on boot)

2. Enable WoL before shutdown:

• sudo sysctl dev.asmc.0.wol=1
• Expected: Returns 1, no errors

3. Verify AUPO was set:

• sudo sysctl dev.asmc.0.wol
• Expected: 1

4. Shutdown system:

• sudo shutdown -p now

5. From another machine, send magic packet:

• wakeonlan -i 192.168.3.255 <MAC_ADDRESS> <-- use your local ip range
• Expected: System powers on and boots

6. After boot, verify WoL state reset:

• sysctl dev.asmc.0.wol
• Expected: 0 (AUPO volatile, resets on boot)

7. Test disable: (it disabled by default)

• sudo sysctl dev.asmc.0.wol=1
• sudo sysctl dev.asmc.0.wol=0
• sudo shutdown -p now
• Send magic packet

Note: My Thunderbolt ethernet cable is broken, so i could not test it in the laptops.

The user need to build rc.d integration or shutdown hook to keep the value set to 1

[seuros]

i got the patch from the wrong branch, the first time.

[markj]

sys/dev/asmc/asmc.c

1681

Missing a newline between this and the previous function.

1698

Is there any reason not to make this sysctl handle a plain int? I don't see one, and it's more natural to do that for plain on/off switches.

[markj]

What email address would you like to use in the commit author field? I see your phabricator account name was changed, and the email isn't available anymore.

[seuros]

[e-mail] (like the previous commits)

[markj]

This version of the patch doesn't apply. Something stripped all of the tabs in the file.

How did you upload the diff?

[seuros]

Updated the diff .

I pasted the diff in the webview.

[markj]

In D54439#1249171, @guest-seuros wrote:

Updated the diff .

I pasted the diff in the webview.

This strips tabs, so I still can't apply the patch to the tree. Please use arc or git arc to upload patches: https://wiki.freebsd.org/Phabricator

[seuros]

Only add dev.asmc.*.wol when AUPO exists; add key constant

[ngie]

sys/dev/asmc/asmc.c

1730

style(9) nit.

1740

1740

I meant to also say, style(9) nit.

[seuros]

Address style(9) nits: remove space in cast, use explicit != 0 comparison