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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: Roland Kletzing <devzero@web.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
devzero@web.de 2008-01-30 13:33:02 +01:00 committed by Ingo Molnar
parent 811a0fff5d
commit 32d0b98980
1 changed files with 65 additions and 0 deletions

View File

@ -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 */
}