expands beyond the limit we will extend the address space before trying
to zero the BSS. This should give us plenty of headroom for modest
expansion of the loader.
Previous revision of this file changed the "boot" commands to take
no arguments from the stack. This is only valid in the case where
a kernel has not been loaded. In that case, load_kernel_and_modules
will be called, which takes a list of arguments from the stack.
When a kernel is presently loaded, though, the list of arguments must
be passed to the boot command, which was the behaviour before the last
revision.
Fix things for both cases.
Noticed by: S-Max and others on that chat room
Taking over the sector following the MBR causes problems on some
machines, and the actual gains are fairly small in terms of how
the space is presently used.
Since we need a number of further features (eg. handling extended
partitions) that can't be readily accommodated in the basic boot0
design anyway, rather choose to implement the additional stuff
separately and concentrate on compatibility rather than features
here.
used by start to find the kernel. Fix this.
Also, boot would proceed immediately in the absence of a path as
argument. Check first if a kernel has already been loaded, and, if
not, fall back to load kernel&modules behavior.
Some further factorizing. I deem this code to be mostly readable by
now! :-)
Many thanks to: Makoto MATSUSHITA <matusita@jp.FreeBSD.org>
The boot-conf and boot code had various bugs, and some of it was big,
ugly, unwieldy, and, sometimes, plain incorrect. I'm just about
completely replaced these ugly parts with something much more manageable.
Minor changes were made to the well-factorized parts of it, to accomodate
the new code.
Of note:
* make sure boot-conf has the exact same behavior wrt boot order
as start.
* Correct both boot and boot-conf so they'll work correctly when
compiled in, as they both had some bugs, minor and major.
* Remove all the crud from loader.4th back into support.4th, for
the first time since boot-conf was first improved. Hurray!
I'm fairly satisfied with the code at this time. Time to see about those
man pages...
to make things more interchangeable between it and the FORTH case.
Perhaps requiring the space is a bit too much, but...
Nothing in the tree seems to produce loader.rc files with comment
line, at this time.
as the kernel name. The one very unfortunate consequence is that kernel
as an absolute path loses the priority. It will only be tried after
/boot/${kernel}/${bootfile}. I'll see what can be done about it later.
Load the first of the following kernels to be found:
${kernel} if ${kernel} is an absolute path
/boot/${kernel}/${kernel}
/boot/${kernel}/${bootfile}
${kernel}/${kernel}
${kernel}/${bootfile}
${kernel}
${bootfile}
The last instance of ${kernel} and ${bootfile} will be treated as a
list of semicolon separated file names, and each will be tried in turn,
from left to right.
Also, for each filename loader(8) will try filename, filename.ko,
filename.gz, filename.ko.gz, in that order, but that's not related
to this code.
This resulted in a major reorganization of the code, and much of what
was accumulating on loader.4th was rightly transfered to support.4th.
The semantics of boot-conf and boot also changed. Both will try to load
a kernel the same as above.
After a kernel was loaded, the variable module_path may get changed. Such
change will happen if the kernel was found with a directory prefix. In
that case, the module path will be set to ${directory};${module_path}.
Next, the modules are loaded as usual.
This is intended so kernel="xyzzy" in /boot/loader.conf will load
/boot/xyzzy/kernel.ko, load system modules from /boot/xyzzy/, and
load third party modules from /boot/modules or /modules. If that doesn't
work, it's a bug.
Also, fix a breakage of "boot" which was recently introduced. Boot without
any arguments would fail. No longer. Also, boot will only unload/reload
if the first argument is a path. If no argument exists or the first
argument is a flag, boot will use whatever is already loaded. I hope this
is POLA. That behavior is markedly different from that of boot-conf, which
will always unload/reload.
The semantics introduced here are experimental. Even if the code works,
we might decide this is not the prefered behavior. If you feel so, send
your feedback. (Yeah, this belongs in a HEADS UP or something, but I've
been working for the past 16 hours on this stuff, so gimme a break.)
Now boot-conf can also receive parameters to be passed to the kernel
being booted. The syntax is the same as in the boot command, so one
boots /kernel.OLD in single-user mode by typing:
boot-conf /kernel.OLD -s instead of
boot-conf -s /kernel.OLD
The syntax still supports use of directory instead of file name, so
boot-conf kernel.OLD -s
may be used to boot /boot/kernel.OLD/kernel.ko in single-user mode.
Notice that if one passes a flag to boot-conf, it will override the
flags set in .conf files, but only for that invocation. If the user
aborts the countdown and tries again without passing any flags, the
flags set in .conf files will be used.
Some factorization was done in the process of enhancing boot-conf,
as it has been growing steadly as features are getting added, becoming
too big for a Forth word. It still could do with more factorization,
as a matter of fact.
Override the builtin "boot" with something based on boot-conf. It will
behave exactly like boot-conf, but booting directly instead of going
through autoboot.
Since we are now pairing kernel and module set in the same directory,
this change to boot makes sense.
load the modules needed according to a file relating module names
(actually, _file_ names, not really modules -- the dependency
stuff is not exported to loader's UI) to PnP IDs.
But it still lacks a number of desired features, and it's too crude
for my tastes. But since I don't have time to work on it, it might
be preferable to make it available to those who might. It's not
installed by default, much less loaded. In fact, it wouldn't even
had a copyright message (who? me? assume responsibility for _this_?),
if the cvs commit hadn't aborted for lack of $FreeBSD$, and I decided
to just cut&paste the stuff from elsewhere.
Also, export the file_findfile() function. Again, this is taken from
work in progress but frozen for the time being. Since it works, I'd
rather commit and remove any uglyness later than hide it on my tree.
code into a more modular interface, with hidden vocabularies and
such. Remove the need to a lot of ugly initialization.
Also, add a few structure definitions, from stuff used on the C
part of loader. Some of this will disappear, and the crude structure
support will most likely be replaced by full-blown OOP support
already present on FICL, but not installed by default. But it was
getting increasingly inconvenient to keep this separate on my tree,
and I already lost lots of work once because of the hurdles, so
commit this.
Anyway, it makes support.4th more structured, and I'm not proceeding
with the work on it any time soon, unfortunately.
gets the name from the environment variable kernelname, which is set
when a kernel is loaded. For this reason, autoboot will _first_ try
to load a kernel, and only proceed with the wait prompt after that
succeeds. If it fails, it will abort immediately.
While I understand some may think this behavior undesirable, I think
it is, overall, the best thing to do, even if we do not consider the
aesthetic issue. Notice that anyone using the default loader.rc
already has the kernel loaded before autoboot.
On unload, unset kernelname.
Separate the code that tries to load a kernel from the list of options
to the function loadakernel(). It is used by both boot() and
autoboot().
