Re: [PATCH] Split of normal mode (version 2)

[Bean]

On Sat, Apr 4, 2009 at 2:40 AM, Yoshinori K. Okuji <address@hidden> wrote:
> On Tuesday 31 March 2009 02:41:14 Bean wrote:
>> Hi,
>>
>> This new patch make some changes based on the discussion of previous patch.
>>
>> 1, Move script engine to script/sh (sh.mod)
>> 2, Move generic menu code to menu (menu.mod)
>> 3, Move text menu viewer to menu/text (textmenu.mod)
>> 4, Move misc function to lib (misc.mod)
>> 5, Move setjmp to lib (setjmp.mod)
>
> I don't agree on the last two. Also, I don't like that you have just removed
> the rescue command.

Hi,

The reason for a separate misc.mod is that it contains pure function
and has no side effect, so other modules can use them freely. In the
other hand, normal.mod does a lot of tasks in the init function, it's
not a good place for common function. Besides, there are already
helper function in the lib directory, like crc and hexdump, it's not
piratical to put each one in a new module, we might just merge them
into one helper module.

The problem with setjmp is that it's platform dependent, so if we keep
it in normal.mod, we must define it in very platform rmk file. But now
setjmp is not used in normal.mod anymore, we could move it out, and
thus make normal.mod platform independent.

>> Now normal.mod only contains the reader code. To configure script
>> engine and viewer, you should add these lines at the beginning of
>> grub.cfg:
>>
>> insmod sh
>> handler parser sh
>> insmod textmenu
>
> I prefer a more sophisticated approach (note: I hate manual loading).
>
> For example, we can allow a config file to have a shebang, like "#!sh". If not
> specified, GRUB can assume that "sh" is used, and load it automatically. This
> kind of technique could even allow for using different languages in one
> setup.
>
> For textmenu, I think it makes sense to have a command "textmenu". Just
> like "boot", GRUB can execute "textmenu" implicitly if a config file defines
> any menu entry but does not execute any menu command. This way, textmenu is
> automatically loaded.

I'm thinking about using environment variable to set handler, for
example, we could set it like this:

set parser=sh
set menu=textmenu
set terminal_output=gfxterm

We could use variable hooks to load the modules on demand.

For textmenu, we could add some test in normal.mod. After the main
config file is parsed, if it still doesn't contain a menu viewer, we
load textmenu automatically.

-- 
Bean