attempted fix for asm in oskit cpuid.c

[spooq]

Hello list,

I tried to fix some errors in cpuid.c ... wouldnt rely on it, my asms
not very good and I havent tested it beyond seeing that it compiles.
Basically it just makes the asm respect gcc using the ebx as a pic
reg. Not sure about the \n\t stuff, it made it work tho.

--- virgin_code/oskit/libkern/x86/cpuid.c       2006-04-02
15:41:55.000000000 +0000
+++ cpuid.c     2006-04-10 17:14:57.000000000 +0000
@@ -39,12 +39,17 @@
                unsigned i;

                cicount++;
-               asm volatile("cpuid"
+               asm volatile(
+               "movl %%ebx, %%edi\n\t"
+               "cpuid\n\t"
+               "movl %1, %%ebx\n\t"
+               "movl %%edi, %%ebx\n\t"
                  : "=a" (ci[0]),
-                   "=b" (ci[1]),
+                   "=r" (ci[1]),
                    "=c" (ci[2]),
                    "=d" (ci[3])
-                 : "a" (2));
+                 : "a" (2)
+                 : "edi");

                for (i = 0; i < 4; i++)
                {
@@ -90,21 +95,29 @@
                         * CPUID is supported, so use it.
                         * First get the vendor ID string.
                         */
-                       asm volatile("cpuid"
+                       asm volatile(
+                       "movl %%ebx, %%edi\n\t"
+                       "cpuid\n\t"
+                       "movl %1, %%ebx\n\t"
+                       "movl %%edi, %%ebx\n\t"
                          : "=a" (highest_val),
-                           "=b" (*((int*)(out_id->vendor_id+0))),
+                           "=r" (*((int*)(out_id->vendor_id+0))),
                            "=d" (*((int*)(out_id->vendor_id+4))),
                            "=c" (*((int*)(out_id->vendor_id+8)))
-                         : "a" (0));
+                         : "a" (0)
+                         : "edi");

                        /* Now the feature information.  */
                        if (highest_val >= 1)
                        {
-                               asm volatile("cpuid"
-                                 : "=a" (*((int*)out_id)),
-                                   "=d" (out_id->feature_flags)
-                                 : "a" (1)
-                                 : "ebx", "ecx");
+                               asm volatile(
+                                       "movl %%ebx, %%edi\n\t"
+                                       "cpuid\n\t"
+                                       "movl %%edi, %%ebx\n\t"
+                                       : "=a" (*((int*)out_id)),
+                                         "=d" (out_id->feature_flags)
+                                       : "a" (1)
+                                       : "ecx","edi");
                        }

                        /* Cache and TLB information.  */

--
spooq