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author | Borislav Petkov <bp@suse.de> | 2014-05-19 20:59:16 +0200 |
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committer | H. Peter Anvin <hpa@zytor.com> | 2014-05-20 20:21:24 -0700 |
commit | 1b1ded57a4f2f4420b4de7c395d1b841d8b3c41a (patch) | |
tree | 1d532435cf6dbff969a3abc80457ae52d9c0a1e5 /arch | |
parent | d6d211db37e75de2ddc3a4f979038c40df7cc79c (diff) | |
download | op-kernel-dev-1b1ded57a4f2f4420b4de7c395d1b841d8b3c41a.zip op-kernel-dev-1b1ded57a4f2f4420b4de7c395d1b841d8b3c41a.tar.gz |
x86, boot: Carve out early cmdline parsing function
Carve out early cmdline parsing function into .../lib/cmdline.c so it
can be used by early code in the kernel proper as well.
Adapted from arch/x86/boot/cmdline.c.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1400525957-11525-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/cmdline.h | 6 | ||||
-rw-r--r-- | arch/x86/lib/Makefile | 2 | ||||
-rw-r--r-- | arch/x86/lib/cmdline.c | 84 |
3 files changed, 91 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cmdline.h b/arch/x86/include/asm/cmdline.h new file mode 100644 index 0000000..e01f7f7 --- /dev/null +++ b/arch/x86/include/asm/cmdline.h @@ -0,0 +1,6 @@ +#ifndef _ASM_X86_CMDLINE_H +#define _ASM_X86_CMDLINE_H + +int cmdline_find_option_bool(const char *cmdline_ptr, const char *option); + +#endif /* _ASM_X86_CMDLINE_H */ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index eabcb6e..4d4f96a 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -16,7 +16,7 @@ clean-files := inat-tables.c obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o -lib-y := delay.o misc.o +lib-y := delay.o misc.o cmdline.o lib-y += thunk_$(BITS).o lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o lib-y += memcpy_$(BITS).o diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c new file mode 100644 index 0000000..422db00 --- /dev/null +++ b/arch/x86/lib/cmdline.c @@ -0,0 +1,84 @@ +/* + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + * + * Misc librarized functions for cmdline poking. + */ +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <asm/setup.h> + +static inline int myisspace(u8 c) +{ + return c <= ' '; /* Close enough approximation */ +} + +/** + * Find a boolean option (like quiet,noapic,nosmp....) + * + * @cmdline: the cmdline string + * @option: option string to look for + * + * Returns the position of that @option (starts counting with 1) + * or 0 on not found. + */ +int cmdline_find_option_bool(const char *cmdline, const char *option) +{ + char c; + int len, pos = 0, wstart = 0; + const char *opptr = NULL; + enum { + st_wordstart = 0, /* Start of word/after whitespace */ + st_wordcmp, /* Comparing this word */ + st_wordskip, /* Miscompare, skip */ + } state = st_wordstart; + + if (!cmdline) + return -1; /* No command line */ + + len = min_t(int, strlen(cmdline), COMMAND_LINE_SIZE); + if (!len) + return 0; + + while (len--) { + c = *(char *)cmdline++; + 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; + else if (!len) /* last word and is matching */ + return wstart; + break; + + case st_wordskip: + if (!c) + return 0; + else if (myisspace(c)) + state = st_wordstart; + break; + } + } + + return 0; /* Buffer overrun */ +} |