xref: /freebsd/stand/i386/libi386/biospnp.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * PnP BIOS enumerator.
32  */
33 
34 #include <stand.h>
35 #include <machine/stdarg.h>
36 #include <bootstrap.h>
37 #include <isapnp.h>
38 #include <btxv86.h>
39 
40 
41 static int	biospnp_init(void);
42 static void	biospnp_enumerate(void);
43 
44 struct pnphandler biospnphandler =
45 {
46     "PnP BIOS",
47     biospnp_enumerate
48 };
49 
50 struct pnp_ICstructure
51 {
52     uint8_t	pnp_signature[4];
53     uint8_t	pnp_version;
54     uint8_t	pnp_length;
55     uint16_t	pnp_BIOScontrol;
56     uint8_t	pnp_checksum;
57     uint32_t	pnp_eventflag;
58     uint16_t	pnp_rmip;
59     uint16_t	pnp_rmcs;
60     uint16_t	pnp_pmip;
61     uint32_t	pnp_pmcs;
62     uint8_t	pnp_OEMdev[4];
63     uint16_t	pnp_rmds;
64     uint32_t	pnp_pmds;
65 } __packed;
66 
67 struct pnp_devNode
68 {
69     uint16_t	dn_size;
70     uint8_t	dn_handle;
71     uint8_t	dn_id[4];
72     uint8_t	dn_type[3];
73     uint16_t	dn_attrib;
74     uint8_t	dn_data[1];
75 } __packed;
76 
77 struct pnp_isaConfiguration
78 {
79     uint8_t	ic_revision;
80     uint8_t	ic_nCSN;
81     uint16_t	ic_rdport;
82     uint16_t	ic_reserved;
83 } __packed;
84 
85 static struct pnp_ICstructure	*pnp_Icheck = NULL;
86 static uint16_t			pnp_NumNodes;
87 static uint16_t			pnp_NodeSize;
88 
89 static void	biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn);
90 static int	biospnp_call(int func, const char *fmt, ...);
91 
92 #define vsegofs(vptr)	(((uint32_t)VTOPSEG(vptr) << 16) + VTOPOFF(vptr))
93 
94 typedef void    v86bios_t(uint32_t, uint32_t, uint32_t, uint32_t);
95 v86bios_t	*v86bios = (v86bios_t *)v86int;
96 
97 #define	biospnp_f00(NumNodes, NodeSize)			biospnp_call(0x00, "ll", NumNodes, NodeSize)
98 #define biospnp_f01(Node, devNodeBuffer, Control)	biospnp_call(0x01, "llw", Node, devNodeBuffer, Control)
99 #define biospnp_f40(Configuration)			biospnp_call(0x40, "l", Configuration)
100 
101 /* PnP BIOS return codes */
102 #define PNP_SUCCESS			0x00
103 #define PNP_FUNCTION_NOT_SUPPORTED	0x80
104 
105 /*
106  * Initialisation: locate the PnP BIOS, test that we can call it.
107  * Returns nonzero if the PnP BIOS is not usable on this system.
108  */
109 static int
110 biospnp_init(void)
111 {
112     struct pnp_isaConfiguration	icfg;
113     char			*sigptr;
114     int				result;
115 
116     /* Search for the $PnP signature */
117     pnp_Icheck = NULL;
118     for (sigptr = PTOV(0xf0000); sigptr < PTOV(0xfffff); sigptr += 16)
119 	if (!bcmp(sigptr, "$PnP", 4)) {
120 	    pnp_Icheck = (struct pnp_ICstructure *)sigptr;
121 	    break;
122 	}
123 
124     /* No signature, no BIOS */
125     if (pnp_Icheck == NULL)
126 	return(1);
127 
128     /*
129      * Fetch the system table parameters as a test of the BIOS
130      */
131     result = biospnp_f00(vsegofs(&pnp_NumNodes), vsegofs(&pnp_NodeSize));
132     if (result != PNP_SUCCESS) {
133 	return(1);
134     }
135 
136     /*
137      * Look for the PnP ISA configuration table
138      */
139     result = biospnp_f40(vsegofs(&icfg));
140     switch (result) {
141     case PNP_SUCCESS:
142 	/* If the BIOS found some PnP devices, take its hint for the read port */
143 	if ((icfg.ic_revision == 1) && (icfg.ic_nCSN > 0))
144 	    isapnp_readport = icfg.ic_rdport;
145 	break;
146     case PNP_FUNCTION_NOT_SUPPORTED:
147 	/* The BIOS says there is no ISA bus (should we trust that this works?) */
148 	printf("PnP BIOS claims no ISA bus\n");
149 	isapnp_readport = -1;
150 	break;
151     }
152     return(0);
153 }
154 
155 static void
156 biospnp_enumerate(void)
157 {
158     uint8_t		Node;
159     struct pnp_devNode	*devNodeBuffer;
160     int			result;
161     struct pnpinfo	*pi;
162     int			count;
163 
164     /* Init/check state */
165     if (biospnp_init())
166 	return;
167 
168     devNodeBuffer = (struct pnp_devNode *)alloca(pnp_NodeSize);
169     Node = 0;
170     count = 1000;
171     while((Node != 0xff) && (count-- > 0)) {
172 	result = biospnp_f01(vsegofs(&Node), vsegofs(devNodeBuffer), 0x1);
173 	if (result != PNP_SUCCESS) {
174 	    printf("PnP BIOS node %d: error 0x%x\n", Node, result);
175 	} else {
176 	    pi = pnp_allocinfo();
177 	    pnp_addident(pi, pnp_eisaformat(devNodeBuffer->dn_id));
178 	    biospnp_scanresdata(pi, devNodeBuffer);
179 	    pnp_addinfo(pi);
180 	}
181     }
182 }
183 
184 /*
185  * Scan the resource data in the node's data area for compatible device IDs
186  * and descriptions.
187  */
188 static void
189 biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn)
190 {
191     u_int	tag, i, rlen, dlen;
192     uint8_t	*p;
193     char	*str;
194 
195     p = dn->dn_data;			/* point to resource data */
196     dlen = dn->dn_size - (p - (uint8_t *)dn);	/* length of resource data */
197 
198     for (i = 0; i < dlen; i+= rlen) {
199 	tag = p[i];
200 	i++;
201 	if (PNP_RES_TYPE(tag) == 0) {
202 	    rlen = PNP_SRES_LEN(tag);
203 	    /* small resource */
204 	    switch (PNP_SRES_NUM(tag)) {
205 
206 	    case COMP_DEVICE_ID:
207 		/* got a compatible device ID */
208 		pnp_addident(pi, pnp_eisaformat(p + i));
209 		break;
210 
211 	    case END_TAG:
212 		return;
213 	    }
214 	} else {
215 	    /* large resource */
216 	    rlen = *(uint16_t *)(p + i);
217 	    i += sizeof(uint16_t);
218 
219 	    switch(PNP_LRES_NUM(tag)) {
220 
221 	    case ID_STRING_ANSI:
222 		str = malloc(rlen + 1);
223 		bcopy(p + i, str, rlen);
224 		str[rlen] = 0;
225 		if (pi->pi_desc == NULL) {
226 		    pi->pi_desc = str;
227 		} else {
228 		    free(str);
229 		}
230 		break;
231 	    }
232 	}
233     }
234 }
235 
236 
237 /*
238  * Make a 16-bit realmode PnP BIOS call.
239  *
240  * The first argument passed is the function number, the last is the
241  * BIOS data segment selector.  Intermediate arguments may be 16 or
242  * 32 bytes in length, and are described by the format string.
243  *
244  * Arguments to the BIOS functions must be packed on the stack, hence
245  * this evil.
246  */
247 static int
248 biospnp_call(int func, const char *fmt, ...)
249 {
250     va_list	ap;
251     const char	*p;
252     uint8_t	*argp;
253     uint32_t	args[4];
254     uint32_t	i;
255 
256     /* function number first */
257     argp = (uint8_t *)args;
258     *(uint16_t *)argp = func;
259     argp += sizeof(uint16_t);
260 
261     /* take args according to format */
262     va_start(ap, fmt);
263     for (p = fmt; *p != 0; p++) {
264 	switch(*p) {
265 
266 	case 'w':
267 	    i = va_arg(ap, u_int);
268 	    *(uint16_t *)argp = i;
269 	    argp += sizeof(uint16_t);
270 	    break;
271 
272 	case 'l':
273 	    i = va_arg(ap, uint32_t);
274 	    *(uint32_t *)argp = i;
275 	    argp += sizeof(uint32_t);
276 	    break;
277 	}
278     }
279     va_end(ap);
280 
281     /* BIOS segment last */
282     *(uint16_t *)argp = pnp_Icheck->pnp_rmds;
283     argp += sizeof(uint16_t);
284 
285     /* prepare for call */
286     v86.ctl = V86_ADDR | V86_CALLF;
287     v86.addr = ((uint32_t)pnp_Icheck->pnp_rmcs << 16) + pnp_Icheck->pnp_rmip;
288 
289     /* call with packed stack and return */
290     v86bios(args[0], args[1], args[2], args[3]);
291     return(v86.eax & 0xffff);
292 }
293