Instead of letting the user to determine whether framebuffer devices
will be created (which is useless because they are gone by now), let's
simplify the flow by allowing the user to choose between full, limited
or disabled functionality. The determination happens only once, so, if
the user decided to disable graphics support, the initialize method
exits immediately. If limited functionality is chosen, then a generic
DisplayConnector is initialized with the preset framebuffer resolution,
if present, and then the initialize method exits. As a default, the code
proceeds to initialize all drivers as usual.
This change allow the user to request the kernel to not use any PCI
resources/devices at all.
Also, don't try to initialize devices that rely on PCI if disabled.
As we don't currently support MSI(X) interrupts, it could be an issue
to boot on some newer hardware. NVMe devices support polling mode
where the driver actively polls for completion instead of waiting for
an interrupt.
The URLs of the form `help://man/<section>/<page>` link to another help
page inside the help application. All previous relative page links are
replaced by this new form. This doesn't change any behavior but it looks
much nicer :^)
Note that man doesn't handle these new links, but the previous relative
links didn't work either.
This allows forcing the use of only the framebuffer set up by the
bootloader and skips instantiating devices for any other graphics
cards that may be present.
The document describes the implications of enabling and disabling that
option on the ability to enable SMP mode, and describes the requirements
for enabling IOAPIC mode even without enabling SMP mode.
'bootmode' now only controls which set of services are started by
SystemServer, so it is more appropriate to rename it to system_mode, and
no longer validate it in the Kernel.
Bootmode used to control framebuffers, panic behavior, and SystemServer.
This patch factors framebuffer control into a separate flag.
Note that the combination 'bootmode=self-test fbdev=on' leads to
unexpected behavior, which can only be fixed in a later commit.
These interfaces are broken for about 9 months, maybe longer than that.
At this point, this is just a dead code nobody tests or tries to use, so
let's remove it instead of keeping a stale code just for the sake of
keeping it and hoping someone will fix it.
To better justify this, I read that OpenBSD removed loadable kernel
modules in 5.7 release (2014), mainly for the same reason we do -
nobody used it so they had no good reason to maintain it.
Still, OpenBSD had LKMs being effectively working, which is not the
current state in our project for a long time.
An arguably better approach to minimize the Kernel image size is to
allow dropping drivers and features while compiling a new image.
This is implemented in Line::Editor meaning not only the Shell will
respect it, but also js, Debugger etc.
Possible values are "ignorespace", "ignoredups" and "ignoreboth", as
documented in Shell-vars(7), for now.
The default value for the anon user (set in .shellrc) is "ignoreboth".
