man/systemd-boot: recommend holding space by default

https://github.com/systemd/systemd/pull/15509/files#r2234113960 complains that the
advice is still not clear enough. systemd-boot itself says
  "Menu hidden. Hold down key at bootup to show menu."
so let's do the same and tell users to hold down space as the first option.
This should work fine for 99% of people. Then invert the following advice to
try repeated pressing as the alternative option.

Also, fix the advice about --boot-loader-menu=. The whole para is about getting
the menu to show, so 0 is not a good value.

Follow-up for https://github.com/systemd/systemd/pull/15509.

(cherry picked from commit 509f701ab3b1294e6935561a2d212db48fccd7c5)

diff --git a/man/systemd-boot.xml b/man/systemd-boot.xml
index 83ef95008834921396cbd70b68808afeac69ec5a..82575d5923dea4202f4b2a1a52c7a215dc769f88 100644 (file)
--- a/man/systemd-boot.xml
+++ b/man/systemd-boot.xml
@@ -290,15 +290,15 @@
     </variablelist>
 
     <para>The boot menu is shown when a non-zero menu timeout has been configured. If the menu timeout has
-    been set to zero, it is sufficient to press any key — before the boot loader initializes — to bring up
-    the boot menu, except for the keys listed immediately above as they directly boot into the selected boot
-    menu item. Note that depending on the firmware implementation the time window where key presses are
-    accepted before the boot loader initializes might be short. If the window is missed, reboot and try
-    again, possibly pressing a suitable key (e.g. the space bar) continuously; on most systems it should be
-    possible to hit the time window after a few attempts. To avoid this problem, consider setting a non-zero
-    timeout, thus showing the boot menu unconditionally. Some desktop environments might offer an option to
-    directly boot into the boot menu, to avoid the problem altogether. Alternatively, use the command line
-    <command>systemctl reboot --boot-loader-menu=0</command> from the shell.</para>
+    been set to zero, hold down a key (<keycap>space</keycap> is recommended) before the boot loader
+    initializes to bring up the boot menu. Note that depending on the firmware implementation the time window
+    where key presses are accepted before the boot loader initializes might be short. If the window is
+    missed, reboot and try again, possibly repeatedly pressing a suitable key; on most systems it should be
+    possible to hit the time window after a few attempts. Keys other than the space bar may be used, except
+    for the keys listed above. If showing the menu on demand doesn't work well, consider setting a non-zero
+    timeout to show the boot menu unconditionally. Some desktop environments might offer an option to boot
+    directly into the boot menu, which also avoids the problem altogether. Alternatively, use the command
+    line <command>systemctl reboot --boot-loader-menu=</command> with a non-zero value from the shell.</para>
 
     <para>In the editor, most keys simply insert themselves, but the following keys
     may be used to perform additional actions:</para>