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authordevzero@web.de <devzero@web.de>2008-01-30 07:33:02 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:33:02 -0500
commit32d0b9898029b7b3c7f161d31f57c4831d9049eb (patch)
tree3423478d043a18042590d494876ae7d0223bcea5 /arch/x86
parent811a0fff5d6e80e18e06be88e0fb685f3924bf8f (diff)
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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/boot/cmdline.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c
index 34bb778c4357..cc65a33bf65c 100644
--- a/arch/x86/boot/cmdline.c
+++ b/arch/x86/boot/cmdline.c
@@ -95,3 +95,68 @@ int cmdline_find_option(const char *option, char *buffer, int bufsize)
95 95
96 return len; 96 return len;
97} 97}
98
99/*
100 * Find a boolean option (like quiet,noapic,nosmp....)
101 *
102 * Returns the position of that option (starts counting with 1)
103 * or 0 on not found
104 */
105int cmdline_find_option_bool(const char *option)
106{
107 u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
108 addr_t cptr;
109 char c;
110 int pos =0 , wstart = 0;
111 const char *opptr = NULL;
112 enum {
113 st_wordstart, /* Start of word/after whitespace */
114 st_wordcmp, /* Comparing this word */
115 st_wordskip, /* Miscompare, skip */
116 } state = st_wordstart;
117
118 if (!cmdline_ptr || cmdline_ptr >= 0x100000)
119 return -1; /* No command line, or inaccessible */
120
121 cptr = cmdline_ptr & 0xf;
122 set_fs(cmdline_ptr >> 4);
123
124 while (cptr < 0x10000) {
125 c = rdfs8(cptr++);
126 pos++;
127
128 switch (state) {
129 case st_wordstart:
130 if (!c)
131 return 0;
132 else if (myisspace(c))
133 break;
134
135 state = st_wordcmp;
136 opptr = option;
137 wstart = pos;
138 /* fall through */
139
140 case st_wordcmp:
141 if (!*opptr)
142 if (!c || myisspace(c))
143 return wstart;
144 else
145 state = st_wordskip;
146 else if (!c)
147 return 0;
148 else if (c != *opptr++)
149 state = st_wordskip;
150 break;
151
152 case st_wordskip:
153 if (!c)
154 return 0;
155 else if (myisspace(c))
156 state = st_wordstart;
157 break;
158 }
159 }
160
161 return 0; /* Buffer overrun */
162}