mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 08:14:15 +08:00
97873a3daf
Based on 1 normalized pattern(s): this file is part of the linux kernel and is made available under the terms of the gnu general public license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 28 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.534229504@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
157 lines
3.1 KiB
C
157 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Simple command-line parser for early boot.
|
|
*/
|
|
|
|
#include "boot.h"
|
|
|
|
static inline int myisspace(u8 c)
|
|
{
|
|
return c <= ' '; /* Close enough approximation */
|
|
}
|
|
|
|
/*
|
|
* Find a non-boolean option, that is, "option=argument". In accordance
|
|
* with standard Linux practice, if this option is repeated, this returns
|
|
* the last instance on the command line.
|
|
*
|
|
* Returns the length of the argument (regardless of if it was
|
|
* truncated to fit in the buffer), or -1 on not found.
|
|
*/
|
|
int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize)
|
|
{
|
|
addr_t cptr;
|
|
char c;
|
|
int len = -1;
|
|
const char *opptr = NULL;
|
|
char *bufptr = buffer;
|
|
enum {
|
|
st_wordstart, /* Start of word/after whitespace */
|
|
st_wordcmp, /* Comparing this word */
|
|
st_wordskip, /* Miscompare, skip */
|
|
st_bufcpy /* Copying this to buffer */
|
|
} state = st_wordstart;
|
|
|
|
if (!cmdline_ptr)
|
|
return -1; /* No command line */
|
|
|
|
cptr = cmdline_ptr & 0xf;
|
|
set_fs(cmdline_ptr >> 4);
|
|
|
|
while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
|
|
switch (state) {
|
|
case st_wordstart:
|
|
if (myisspace(c))
|
|
break;
|
|
|
|
/* else */
|
|
state = st_wordcmp;
|
|
opptr = option;
|
|
/* fall through */
|
|
|
|
case st_wordcmp:
|
|
if (c == '=' && !*opptr) {
|
|
len = 0;
|
|
bufptr = buffer;
|
|
state = st_bufcpy;
|
|
} else if (myisspace(c)) {
|
|
state = st_wordstart;
|
|
} else if (c != *opptr++) {
|
|
state = st_wordskip;
|
|
}
|
|
break;
|
|
|
|
case st_wordskip:
|
|
if (myisspace(c))
|
|
state = st_wordstart;
|
|
break;
|
|
|
|
case st_bufcpy:
|
|
if (myisspace(c)) {
|
|
state = st_wordstart;
|
|
} else {
|
|
if (len < bufsize-1)
|
|
*bufptr++ = c;
|
|
len++;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (bufsize)
|
|
*bufptr = '\0';
|
|
|
|
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(unsigned long cmdline_ptr, const char *option)
|
|
{
|
|
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)
|
|
return -1; /* No command line */
|
|
|
|
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 */
|
|
}
|