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Feature #13986
closed
usmn(7D) could support writing
Start date:
Due date:
% Done:
100%
Estimated time:
Difficulty:
Medium
Tags:
Gerrit CR:
External Bug:
Description
In #13983 we added the support to read form the AMD SMN. For various prorotyping purposes it can be valuable to be valuable to be able to write to it without spinning up custom kernel modules. This adds the stubbed out USMN_WRITE ioctl. The use of this style requires full hardware manipulation privilege and it is not installed on systems by default.
Here's an example of using it to basically drive the HSMP interface's test function which adds 1 to a register:
rm@iliad /ws/rm/usmn/usr/src/cmd/amdzen $ pfexec ./usmn -d /devices/pseudo/amdzen@0/usmn@2:usmn.0 -w 0 3B10980 rm@iliad /ws/rm/usmn/usr/src/cmd/amdzen $ pfexec ./usmn -d /devices/pseudo/amdzen@0/usmn@2:usmn.0 -w 23 3B109E0 rm@iliad /ws/rm/usmn/usr/src/cmd/amdzen $ pfexec ./usmn -d /devices/pseudo/amdzen@0/usmn@2:usmn.0 -w 1 3B10534 rm@iliad /ws/rm/usmn/usr/src/cmd/amdzen $ pfexec ./usmn -d /devices/pseudo/amdzen@0/usmn@2:usmn.0 3B10534 3B10980 3B109E0 0x3b10534: 0x1 0x3b10980: 0x1 0x3b109e0: 0x24
This was tested by basic usage of it as illustrated above.
Related issues
Updated by Gergő Mihály Doma almost 2 years ago
- Related to Feature #13146: Want a driver for AMD SMN user access added
Updated by Electric Monk almost 2 years ago
- Status changed from New to Closed
- % Done changed from 90 to 100
git commit f198607dfbf80950ec14f7c1fecf634f2da7ebb0
commit f198607dfbf80950ec14f7c1fecf634f2da7ebb0
Author: Robert Mustacchi <rm@fingolfin.org>
Date: 2021-08-02T23:19:07.000Z
13986 usmn(7D) could support writing
Reviewed by: Gergő Mihály Doma <domag02@gmail.com>
Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Andy Fiddaman <andy@omnios.org>
Approved by: Richard Lowe <richlowe@richlowe.net>
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