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Commit 32d0b989 authored by devzero@web.de's avatar devzero@web.de Committed by Ingo Molnar
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x86 setup: early cmdline parser handle boolean options 



This patch extends the early commandline parser to support boolean options.
The current version in mainline only supports parsing "option=arg" value pairs.

With this it should be easy making other messages like "Uncompressing kernel"
honour the "quiet" parameter, too.

Signed-off-by: default avatarRoland Kletzing <devzero@web.de>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 811a0fff

arch/x86/boot/cmdline.c

+65 −0
Original line number Diff line number Diff line
@@ -95,3 +95,68 @@ int cmdline_find_option(const char *option, char *buffer, int bufsize) 


	return len;

}



/*

 * Find a boolean option (like quiet,noapic,nosmp....)

 *

 * Returns the position of that option (starts counting with 1)

 * or 0 on not found

 */

int cmdline_find_option_bool(const char *option)

{

	u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;

	addr_t cptr;

	char c;

	int pos =0 , wstart = 0;

	const char *opptr = NULL;

	enum {

		st_wordstart,	/* Start of word/after whitespace */

		st_wordcmp,	/* Comparing this word */

		st_wordskip,	/* Miscompare, skip */

	} state = st_wordstart;



	if (!cmdline_ptr || cmdline_ptr >= 0x100000)

		return -1;	/* No command line, or inaccessible */



	cptr = cmdline_ptr & 0xf;

	set_fs(cmdline_ptr >> 4);



	while (cptr < 0x10000) {

		c = rdfs8(cptr++);

		pos++;



		switch (state) {

		case st_wordstart:

			if (!c)

				return 0;

			else if (myisspace(c))

				break;



			state = st_wordcmp;

			opptr = option;

			wstart = pos;

			/* fall through */



		case st_wordcmp:

			if (!*opptr)

				if (!c || myisspace(c))

					return wstart;

				else

					state = st_wordskip;

			else if (!c)

				return 0;

			else if (c != *opptr++)

				state = st_wordskip;

			break;



		case st_wordskip:

			if (!c)

				return 0;

			else if (myisspace(c))

				state = st_wordstart;

			break;

		}

	}



	return 0;	/* Buffer overrun */

}