This should be functional and roughly equivalent to the Forth version.
Stop doing a loadelf() on menu exit now that we can DTRT with boot
invocations. autoboot interception will follow not long after.
core.boot and core.autoboot may both take arguments; add a helper to cleanly
append an argstring to the given loader command.
Also provide a popFrontTable() that we'll use pop the command name off of an
argv table. We don't have the table library included, and including it is
non-trivial, so we'll implement this one function that we need in lua for
the time being.
If the user's selected a kernel, we really should be trying to load that one
instead of falling back to some default kernel.
This should generally be a no-op and most desirable, unless you really
enjoyed surprises.
Carousel storage doesn't need to happen in the menu module, and indeed
storing it there introduces a circular reference between drawer and menu
that only works because of global pollution in loader.lua.
Carousel choices generally map to config entries anyways, making it as good
of place as any to store these. Move {get,set}CarouselIndex functionality
out into config so that drawer and menu may both use it. If we had more
carousel functionality, it might make sense to create a carousel module, but
this is not the case.
If we failed to execute the input line as pure lua, run the command through
parse for consistent argument parsing. Pass the parsed arguments through to
a global "cli_execute" written in Lua, which is expected to either handle it
or pass it back through to interp_builtin_cmd (via loader.command).
lua-handled cli commands will then exist as globals in whatever module they
most belong in, and invocations at the loader prompt will magically dispatch
to them if they exist.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D14450
We follow pretty closely the following structure of a module:
1. Copyright notice
2. Module requires
3. Module local declarations
4. Module local definitions
5. Module exports
6. return
Re-organize the one-offs (config/drawer) and denote the start of module
exports with a comment.
Declare these adjacent to the local definitions at the top of the module,
and make sure they're actually declared local to pollute global namespace a
little bit less.
This refactor makes it straightforward to add new logos for drawing and
organizes logo definitions in a logical manner.
The graphic to be drawn for each logo may again be modified outside of
drawer, but it must be done on a case-by-case basis as a modification to the
loader_logo.
As part of an effort to slowly reduce our exports overall to a set of stable
properties/functions, go ahead and reduce what drawer exposes to others.
The graphics should generally not be modified on their own, but their
position could be modified if additional grahics also need to be drawn.
Export position/shift information, but leave the actual graphic local to
the module.
The next step will be to create a 'menudef' that gets exported instead, with
each entry in the menudef table describing the graphic to be drawn along
with specific positioning information.
Pull out specialized naming behavior into drawer.menu_name_handlers. This is
currently only needed for the carousel entry, where naming is based on the
current choice and the menu item purposefully does not store this state.
The setup was designed so that every type can have a special name handler,
and the default action is to simply use the result of entry.name().
This is a bit cleaner than our former method of an if ... else chain of
handlers. Store handlers in the menu.handlers table so that they may be
added to or removed dynamically.
All handlers take the current menu and selected entry as parameters, and
their return value indicates whether the menu processor should continue or
not. An omitted return value or 'true' will indicate that we should
continue, while returning 'false' will indicate that we should exit the
current menu.
The omitted return value behavior is due to continuing the loop being the
more common situation.
Building the swapped welcome menu (first two items swapped) is kind of a
sluggish, because it requires a full (recrusive) shallow copy of the welcome
menu. Cache the result of that and re-use it later, instead of building it
everytime.
While here, don't create temporary locals just for swapping. The following
is just as good:
x, y = y, x;
Reported by: Alexander Nasonov <alnsn@yandex.ru> (swapping)
[Enter] should be moved to the single user menu item when we swap them.
Define a non-standard menu entry function "alternate_name" to use for this
purpose for ultimate flexibility if we change our minds later. When we're
booting single user, make a shallow copy of the menu that we'd normally
display and swap the items and their name functions to use alternate_name
instead. Toggling single user in the options menu and going back to the main
menu will now correctly reflect the current boot setting with the first two
menu options and "[Enter]" will always be on the right one.
This shallow copy technique has the chance of being quite slow since it's
done on every redraw, but in my testing it does not seem to make any obvious
difference.
shallowCopyTable could likely belong better in a general-purpose utility
module, but this (and the key constnats) are the only candidates we have at
the moment so we'll drop it into our core stuff for the moment and consider
re-organization at a later date.
lualoader does a pretty good job of reverting any environment changes now.
It will even wipe out boot_verbose if it's set explicitly in loader.conf(5)
and overwritten in the boot options menu.
Future work will likely change this, as explicit choices made in the menu
should probably override the new loader.conf(5). I don't suspect this will
cause much grief, though, so it is not a high priority until boot
environment support actually lands.
This will be used when boot environment support lands to make a good-faith
effort to apply any new loader.conf(5) environment settings atop the default
configuration that we started with.
If we've fetched menu.entries and it turns out it's a function, call it to
get the actual menu entries.
This will be used to swap multi-/single- user boot options if we're booting
single user by default (boot_single="YES" in loader.conf(5)). It can also be
used fairly easily for other non-standard situations.
Instead of directly listing them in menu.welcome and menu.boot_options,
store them at menu.welcome.entries and welcome.boot_options.entries.
This will come into play later when we need to re-order the welcome menu if
boot_single is specified.
Menus are actually defined as entries in the 'menu' table. These local
declarations have not been used in the history of our in-tree lua scripts,
so give them the boot.
Loading the kernel and modules can be really slow. Loading before the menu
draws and every time one changes kernel/boot environment is even more
painful.
Defer loading until we either boot, auto-boot, or escape to loader prompt.
We still need to deal with configuration changes as the boot environment
changes, but this is generally much quicker.
This commit strips all ELF loading out of config.load/config.reload so that
these are purely for configuration. config.loadelf has been created to deal
with kernel/module loads. Unloading logic has been ripped out, as we won't
need to deal with it in the menu anymore.
Discussed in part with: allanjude
r329550 introduced config.kernel_loaded. config.load() doesn't provide a
means of overriding the kernel to load, but that likely isn't necessary as
it will not be a common case. When loading the kernel, just attempt to load
the kernel previously loaded and specified in config.kernel_loaded.
If we haven't loaded a kernel yet, config.kernel_loaded will be unset/nil
and the "default"/first kernel found will be loaded. If we've loaded a
kernel, we'll try to load that same kernel again and fallback to the default
kernel if we need to.
This in also in support of upcoming boot environment support.
'nil' means the 'first kernel found in module_path', which is the same
interpretation as passing 'nil' to loadkernel.
Otherwise, it denotes the name of a kernel that we've successfully loaded.
When reloaded later, we will still need to do the full search again to
locate the actual kernel in case things have changed, so just the name is
good enough.
This is in support of upcoming boot environment support. vfs.root.mountfrom
and currdev will be changed, then we will reload configuration and attempt
to reload the currently chosen kernel unless we shouldn't.
In the worst case scenario, we have no passwords to prompt for and we end up
just clearing the screen twice before we draw the menu or proceed with boot.
In the best case scenario, we don't try drawing password prompts amidst a
bunch of kernel/module loading.
Some other points I think we need to be consistent on:
- Spacing around string concatenation (always)
- Test against 'nil' explicitly rather than relying on 'not' for things that
reasonably won't be returning a boolean. e.g. loader.getenv
Eventually this will all get formalized somewhere.
Once we've successfully loaded a kernel, we add its directory to
module_path. If we switch kernels with the kernel selector, we again prepend
the kernel directory to the current module_path and end up with multiple
kernel paths, potentially with mismatched kernel/modules, added to
module_path.
Fix it by caching module_path at load() time and using the cached version
whenever we load a new kernel.
