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author | devzero@web.de <devzero@web.de> | 2008-01-30 13:33:02 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:33:02 +0100 |
commit | 32d0b9898029b7b3c7f161d31f57c4831d9049eb (patch) | |
tree | 3423478d043a18042590d494876ae7d0223bcea5 /arch/x86/boot/cmdline.c | |
parent | 811a0fff5d6e80e18e06be88e0fb685f3924bf8f (diff) | |
download | kernel_samsung_smdk4412-32d0b9898029b7b3c7f161d31f57c4831d9049eb.zip kernel_samsung_smdk4412-32d0b9898029b7b3c7f161d31f57c4831d9049eb.tar.gz kernel_samsung_smdk4412-32d0b9898029b7b3c7f161d31f57c4831d9049eb.tar.bz2 |
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/boot/cmdline.c')
-rw-r--r-- | arch/x86/boot/cmdline.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c index 34bb778..cc65a33 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) 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 */ +} |