freebsd-skq/sys/boot/forth/loader.4th
Luigi Rizzo 065188a630 This patch introduces a number of simplifications to the Forth
functions used in the bootloader. The goal is to make the code more
readable and smaller (especially because we have size issues
in the loader's environment).

High level description of the changes:
+ define some string manipulation functions to improve readability;
+ create functions to manipulate module descriptors, removing some
  duplicated code;
+ rename the error codes to ESOMETHING;
+ consistently use set_environment_variable (which evaluates
  $variables) when interpreting variable=value assignments;

I have tested the code, but there might be code paths that I have
not traversed so please let me know of any issues.

Details of this change:

--- loader.4th ---
+ add some module operators, to remove duplicated code while parsing
  module-related commands:

        set-module-flag
        enable-module
        disable-module
        toggle-module
        show-module

--- pnp.4th ---
+ move here the definition related to the pnp devices list, e.g.
  STAILQ_* , pnpident, pnpinfo

--- support.4th ---
+ rename error codes to capital e.g. ENOMEM EFREE ... and do obvious
  changes related to the renaming;
+ remove unused structures (those relevant to pnp are moved to pnp.4th)
+ various string functions
  - strlen removed (it is an internal function)
  - strchr, defined as the C function
  - strtype -- type a string to output
  - strref -- assign a reference to the string on the stack
  - unquote -- remove quotes from a string

+ remove reset_line_buffer

+ move up the 'set_environment_variable' function (which now
  uses the interpreter, so $variables are evaluated).
  Use the function in various places

+ add a 'test_file function' for debugging purposes

MFC after:	4 weeks
2009-01-05 20:09:54 +00:00

216 lines
5.6 KiB
Forth

\ Copyright (c) 1999 Daniel C. Sobral <dcs@freebsd.org>
\ All rights reserved.
\
\ Redistribution and use in source and binary forms, with or without
\ modification, are permitted provided that the following conditions
\ are met:
\ 1. Redistributions of source code must retain the above copyright
\ notice, this list of conditions and the following disclaimer.
\ 2. Redistributions in binary form must reproduce the above copyright
\ notice, this list of conditions and the following disclaimer in the
\ documentation and/or other materials provided with the distribution.
\
\ THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
\ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
\ ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
\ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
\ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
\ OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
\ LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
\ OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\ SUCH DAMAGE.
\
\ $FreeBSD$
s" arch-i386" environment? [if] [if]
s" loader_version" environment? [if]
11 < [if]
.( Loader version 1.1+ required) cr
abort
[then]
[else]
.( Could not get loader version!) cr
abort
[then]
[then] [then]
256 dictthreshold ! \ 256 cells minimum free space
2048 dictincrease ! \ 2048 additional cells each time
include /boot/support.4th
\ ***** boot-conf
\
\ Prepares to boot as specified by loaded configuration files.
only forth also support-functions also builtins definitions
: 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 )
1 boot exit
then
load_kernel_and_modules
?dup if exit then
0 1 boot exit
then
else
s" kernelname" getenv? if ( a kernel has been loaded )
1 boot exit
then
load_kernel_and_modules
?dup if exit then
0 1 boot exit
then
load_kernel_and_modules
?dup 0= if 0 1 boot then
;
: boot-conf
0= if ( interpreted ) get_arguments then
0 1 unload drop
load_kernel_and_modules
?dup 0= if 0 1 autoboot then
;
also forth definitions also builtins
builtin: boot
builtin: boot-conf
only forth definitions also support-functions
\ ***** check-password
\
\ If a password was defined, execute autoboot and ask for
\ password if autoboot returns.
\ Do not exit unless the right password is given.
: check-password
password .addr @ if
0 autoboot
false >r
begin
bell emit bell emit
." Password: "
password .len @ read-password
dup password .len @ = if
2dup password .addr @ password .len @
compare 0= if r> drop true >r then
then
drop free drop
r@
until
r> drop
then
;
\ ***** start
\
\ Initializes support.4th global variables, sets loader_conf_files,
\ process conf files, and, if any one such file was succesfully
\ read to the end, load kernel and modules.
: start ( -- ) ( throws: abort & user-defined )
s" /boot/defaults/loader.conf" initialize
include_conf_files
include_nextboot_file
\ Will *NOT* try to load kernel and modules if no configuration file
\ was succesfully loaded!
any_conf_read? if
load_kernel
load_modules
then
;
\ ***** initialize
\
\ Overrides support.4th initialization word with one that does
\ everything start one does, short of loading the kernel and
\ modules. Returns a flag
: initialize ( -- flag )
s" /boot/defaults/loader.conf" initialize
include_conf_files
include_nextboot_file
any_conf_read?
;
\ ***** read-conf
\
\ Read a configuration file, whose name was specified on the command
\ line, if interpreted, or given on the stack, if compiled in.
: (read-conf) ( addr len -- )
conf_files string=
include_conf_files \ Will recurse on new loader_conf_files definitions
;
: read-conf ( <filename> | addr len -- ) ( throws: abort & user-defined )
state @ if
\ Compiling
postpone (read-conf)
else
\ Interpreting
bl parse (read-conf)
then
; immediate
\ show, enable, disable, toggle module loading. They all take module from
\ the next word
: set-module-flag ( module_addr val -- ) \ set and print flag
over module.flag !
dup module.name strtype
module.flag @ if ." will be loaded" else ." will not be loaded" then cr
;
: enable-module find-module ?dup if true set-module-flag then ;
: disable-module find-module ?dup if false set-module-flag then ;
: toggle-module find-module ?dup if dup module.flag @ 0= set-module-flag then ;
\ ***** show-module
\
\ Show loading information about a module.
: show-module ( <module> -- ) find-module ?dup if show-one-module then ;
\ Words to be used inside configuration files
: retry false ; \ For use in load error commands
: ignore true ; \ For use in load error commands
\ Return to strict forth vocabulary
: #type
over - >r
type
r> spaces
;
: .? 2 spaces 2swap 15 #type 2 spaces type cr ;
: ?
['] ? execute
s" boot-conf" s" load kernel and modules, then autoboot" .?
s" read-conf" s" read a configuration file" .?
s" enable-module" s" enable loading of a module" .?
s" disable-module" s" disable loading of a module" .?
s" toggle-module" s" toggle loading of a module" .?
s" show-module" s" show module load data" .?
;
only forth also