1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  (C) 2003  Bruno Ducrot
4 *  (C) 2004  Dominik Brodowski <linux@dominikbrodowski.de>
5 *
6 * Based on code found in
7 * linux/include/asm-i386/ist.h and linux/arch/i386/kernel/setup.c
8 * and originally developed by Andy Grover <andrew.grover@intel.com>
9 */
10
11#include <stdio.h>
12#include <string.h>
13#include <lrmi.h>
14
15int main (void)
16{
17	struct LRMI_regs	r;
18	int			retval;
19
20	if (!LRMI_init())
21		return 0;
22
23	memset(&r, 0, sizeof(r));
24
25	r.eax = 0x0000E980;
26	r.edx = 0x47534943;
27
28	retval = LRMI_int(0x15, &r);
29
30	if (!retval) {
31		printf("Failed!\n");
32		return 0;
33	}
34	if (r.eax == 0x47534943) {
35		printf("BIOS supports GSIC call:\n");
36		printf("\tsignature: %c%c%c%c\n",
37		       (r.eax >> 24) & 0xff,
38		       (r.eax >> 16) & 0xff,
39		       (r.eax >> 8) & 0xff,
40		       (r.eax) & 0xff);
41		printf("\tcommand port = 0x%.4x\n",
42		       r.ebx & 0xffff);
43		printf("\tcommand =      0x%.4x\n",
44		       (r.ebx >> 16) & 0xffff);
45		printf("\tevent port =   0x%.8x\n", r.ecx);
46		printf("\tflags =        0x%.8x\n", r.edx);
47		if (((r.ebx >> 16) & 0xffff) != 0x82) {
48			printf("non-default command value. If speedstep-smi "
49			       "doesn't work out of the box,\nyou may want to "
50			       "try out the default value by passing "
51			       "smi_cmd=0x82 to the module\n ON YOUR OWN "
52			       "RISK.\n");
53		}
54		if ((r.ebx & 0xffff) != 0xb2) {
55			printf("non-default command port. If speedstep-smi "
56			       "doesn't work out of the box,\nyou may want to "
57			       "try out the default value by passing "
58			       "smi_port=0x82 to the module\n ON YOUR OWN "
59			       "RISK.\n");
60		}
61	} else {
62		printf("BIOS DOES NOT support GSIC call.  Dumping registers anyway:\n");
63		printf("eax = 0x%.8x\n", r.eax);
64		printf("ebx = 0x%.8x\n", r.ebx);
65		printf("ecx = 0x%.8x\n", r.ecx);
66		printf("edx = 0x%.8x\n", r.edx);
67		printf("Note also that some BIOS do not support the initial "
68		       "GSIC call, but the newer\nspeedstep-smi driver may "
69		       "work.\nFor this, you need to pass some arguments to "
70		       "the speedstep-smi driver:\n");
71		printf("\tsmi_cmd=0x?? smi_port=0x?? smi_sig=1\n");
72		printf("\nUnfortunately, you have to know what exactly are "
73		       "smi_cmd and smi_port, and this\nis system "
74		       "dependent.\n");
75	}
76	return 1;
77}
78