x86, setup: reorganize the early console setup

[net-next-2.6.git] / arch / x86 / boot / cmdline.c

diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c
index 34bb778c4357b9492d020ff234e39eb4a09fa6a1..6b3b6f708c04262c02a788f815d1feac7d25786b 100644 (file)
--- a/arch/x86/boot/cmdline.c
+++ b/arch/x86/boot/cmdline.c
@@ -9,8 +9,6 @@
  * ----------------------------------------------------------------------- */
 
 /*
- * arch/i386/boot/cmdline.c
- *
  * Simple command-line parser for early boot.
  */
 
@@ -29,9 +27,8 @@ static inline int myisspace(u8 c)
  * 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(const char *option, char *buffer, int bufsize)
+int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize)
 {
-       u32 cmdline_ptr = boot_params.hdr.cmd_line_ptr;
        addr_t cptr;
        char c;
        int len = -1;
@@ -95,3 +92,67 @@ 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(u32 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 || 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 */
+}