> On Feb 19, 2018, at 4:32 PM, Warner Losh <i...@bsdimp.com> wrote: > > > >> On Mon, Feb 19, 2018 at 2:57 PM, Devin Teske <dte...@freebsd.org> wrote: >> >> >> > On Feb 19, 2018, at 2:21 PM, Kyle Evans <kev...@freebsd.org> wrote: >> > >> > It seems that the Forth loader might be doing something sneaky and >> > replacing the standard common "boot" with a Forth boot that handles >> > this a lot better. CC'ing dteske@ so they can confirm. >> >> I can indeed confirm this as fact. >> >> Not able to help much because I am driving cross-country (San Francisco to >> Orlando) right now with the spouse and dog. >> >> We get back March 3rd, but I will be checking-in from time to time for >> sporadic responses during downtime. > > The command in loader.4th is defined as: > > : boot > 0= if ( interpreted ) get_arguments then > > \ Unload only if a path was passed > dup if > >r over r> swap > c@ [char] - <> if > 0 1 unload drop > else > s" kernelname" getenv? if ( a kernel has been loaded ) > try-menu-unset > bootmsg 1 boot exit > then > load_kernel_and_modules > ?dup if exit then > try-menu-unset > bootmsg 0 1 boot exit > then > else > s" kernelname" getenv? if ( a kernel has been loaded ) > try-menu-unset > bootmsg 1 boot exit > then > load_kernel_and_modules > ?dup if exit then > try-menu-unset > bootmsg 0 1 boot exit > then > load_kernel_and_modules > ?dup 0= if bootmsg 0 1 boot then > ; > > The thing to know here is when you see 'boot' as part of above script, it's > calling the 'boot' cli command, not itself recursively. >
What is actually going on is that when the “boot” function is compiled, the reference to “boot” inside it is to the already-existing word defined previously. Forth allows you to have multiply-defined names. The “boot” command inside the “boot” function is replaced with the address of previous boot during function compilation because the function is m not defined and given an address in the dictionary until it is completed (last line compiled). — Devin _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
