The switch to lualoader creates a problem with userboot: the host is
inclined to build userboot with Lua, but the host userboot's interpreter
must match what's available on the guest. For almost all FreeBSD guests in
the wild, Lua is not yet available and a Lua-based userboot will fail.
This revision updates userboot protocol to version 5, which adds a
swap_interpreter callback to request a different interpreter, and tries to
determine the proper interpreter to be used based on how the guest
/boot/loader is compiled. This is still a bit of a guess, but it's likely
the best possible guess we can make in order to get it right. The
interpreter is now embedded in the resulting executable, so we can open
/boot/loader on the guest and hunt that down to derive the interpreter it
was built with.
Using -l with bhyveload will not allow an intepreter swap, even if the
loader specified happens to be a userboot with the wrong interpreter. We'll
simply complain about the mismatch and bail out.
For legacy guests without the interpreter marker, we assume they're 4th.
For new guests with the interpreter marker, we'll read it and swap over
to the proper interpreter if it doesn't match what the userboot we're using
was compiled with.
Both flavors of userboot are installed by default, userboot_4th.so and
userboot_lua.so. This fixes the build WITHOUT_FORTH as a coincidence, which
was broken by userboot being forced to 4th.
Reviewed by: imp, jhb, araujo (earlier version)
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D16945
reflect what scripting language was compiled into the loader. I
anticipate that being able to find this out quickly from the OK prompt
will be useful in troubleshooting in the future.
akin to what Pedro Souza and Wojciech Koszek did in the lua GSoC with
interp.h, interp_simple.c and changes to interp.c and interp_forth.c,
but completely redone from scratch.
This effectively restores the spirit of r326712 (my first attempt to
bring in Pedro's and Wojciech's work) updated for new requirements
that had silently broke their original work. This change also differs
by using fixed function names instead of function pointers to simply
things. Only one interpreter at a time may be compiled in.
Also of note: we take a mutable string, pass it in via a const char *
pointer into intrp_forth's interp_run(). We then cast away the const
to pass into ficlExec since ficl would require extensive changes to
properly const-poison. See Sections 6.5.2.5 and 6.7.3 of C11 standard
noting it's only UB if you modify a const object through a non-const
pointer, but not char [] -> const char * -> char * as here.
Create an interp class. Use it to separate out the different types of
interpreters: forth and simple with function pointers rather than
via #ifdefs.
Obtained from: lua boot loader project
(via https://bsdimp@github.com/bsdimp/freebsd.git lua-bootloader)
Sponsored by: Netflix
