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 
29 /*
30  * PnP BIOS enumerator.
31  */
32 
33 #include <stand.h>
34 #include <machine/stdarg.h>
35 #include <bootstrap.h>
36 #include <isapnp.h>
37 #include <btxv86.h>
38 
39 
40 static int	biospnp_init(void);
41 static void	biospnp_enumerate(void);
42 
43 struct pnphandler biospnphandler =
44 {
45     "PnP BIOS",
46     biospnp_enumerate
47 };
48 
49 struct pnp_ICstructure
50 {
51     u_int8_t	pnp_signature[4];
52     u_int8_t	pnp_version;
53     u_int8_t	pnp_length;
54     u_int16_t	pnp_BIOScontrol;
55     u_int8_t	pnp_checksum;
56     u_int32_t	pnp_eventflag;
57     u_int16_t	pnp_rmip;
58     u_int16_t	pnp_rmcs;
59     u_int16_t	pnp_pmip;
60     u_int32_t	pnp_pmcs;
61     u_int8_t	pnp_OEMdev[4];
62     u_int16_t	pnp_rmds;
63     u_int32_t	pnp_pmds;
64 } __packed;
65 
66 struct pnp_devNode
67 {
68     u_int16_t	dn_size;
69     u_int8_t	dn_handle;
70     u_int8_t	dn_id[4];
71     u_int8_t	dn_type[3];
72     u_int16_t	dn_attrib;
73     u_int8_t	dn_data[1];
74 } __packed;
75 
76 struct pnp_isaConfiguration
77 {
78     u_int8_t	ic_revision;
79     u_int8_t	ic_nCSN;
80     u_int16_t	ic_rdport;
81     u_int16_t	ic_reserved;
82 } __packed;
83 
84 static struct pnp_ICstructure	*pnp_Icheck = NULL;
85 static u_int16_t		pnp_NumNodes;
86 static u_int16_t		pnp_NodeSize;
87 
88 static void	biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn);
89 static int	biospnp_call(int func, const char *fmt, ...);
90 
91 #define vsegofs(vptr)	(((u_int32_t)VTOPSEG(vptr) << 16) + VTOPOFF(vptr))
92 
93 typedef void    v86bios_t(u_int32_t, u_int32_t, u_int32_t, u_int32_t);
94 v86bios_t	*v86bios = (v86bios_t *)v86int;
95 
96 #define	biospnp_f00(NumNodes, NodeSize)			biospnp_call(0x00, "ll", NumNodes, NodeSize)
97 #define biospnp_f01(Node, devNodeBuffer, Control)	biospnp_call(0x01, "llw", Node, devNodeBuffer, Control)
98 #define biospnp_f40(Configuration)			biospnp_call(0x40, "l", Configuration)
99 
100 /* PnP BIOS return codes */
101 #define PNP_SUCCESS			0x00
102 #define PNP_FUNCTION_NOT_SUPPORTED	0x80
103 
104 /*
105  * Initialisation: locate the PnP BIOS, test that we can call it.
106  * Returns nonzero if the PnP BIOS is not usable on this system.
107  */
108 static int
biospnp_init(void)109 biospnp_init(void)
110 {
111     struct pnp_isaConfiguration	icfg;
112     char			*sigptr;
113     int				result;
114 
115     /* Search for the $PnP signature */
116     pnp_Icheck = NULL;
117     for (sigptr = PTOV(0xf0000); sigptr < PTOV(0xfffff); sigptr += 16)
118 	if (!bcmp(sigptr, "$PnP", 4)) {
119 	    pnp_Icheck = (struct pnp_ICstructure *)sigptr;
120 	    break;
121 	}
122 
123     /* No signature, no BIOS */
124     if (pnp_Icheck == NULL)
125 	return(1);
126 
127     /*
128      * Fetch the system table parameters as a test of the BIOS
129      */
130     result = biospnp_f00(vsegofs(&pnp_NumNodes), vsegofs(&pnp_NodeSize));
131     if (result != PNP_SUCCESS) {
132 	return(1);
133     }
134 
135     /*
136      * Look for the PnP ISA configuration table
137      */
138     result = biospnp_f40(vsegofs(&icfg));
139     switch (result) {
140     case PNP_SUCCESS:
141 	/* If the BIOS found some PnP devices, take its hint for the read port */
142 	if ((icfg.ic_revision == 1) && (icfg.ic_nCSN > 0))
143 	    isapnp_readport = icfg.ic_rdport;
144 	break;
145     case PNP_FUNCTION_NOT_SUPPORTED:
146 	/* The BIOS says there is no ISA bus (should we trust that this works?) */
147 	printf("PnP BIOS claims no ISA bus\n");
148 	isapnp_readport = -1;
149 	break;
150     }
151     return(0);
152 }
153 
154 static void
biospnp_enumerate(void)155 biospnp_enumerate(void)
156 {
157     u_int8_t		Node;
158     struct pnp_devNode	*devNodeBuffer;
159     int			result;
160     struct pnpinfo	*pi;
161     int			count;
162 
163     /* Init/check state */
164     if (biospnp_init())
165 	return;
166 
167     devNodeBuffer = (struct pnp_devNode *)alloca(pnp_NodeSize);
168     Node = 0;
169     count = 1000;
170     while((Node != 0xff) && (count-- > 0)) {
171 	result = biospnp_f01(vsegofs(&Node), vsegofs(devNodeBuffer), 0x1);
172 	if (result != PNP_SUCCESS) {
173 	    printf("PnP BIOS node %d: error 0x%x\n", Node, result);
174 	} else {
175 	    pi = pnp_allocinfo();
176 	    pnp_addident(pi, pnp_eisaformat(devNodeBuffer->dn_id));
177 	    biospnp_scanresdata(pi, devNodeBuffer);
178 	    pnp_addinfo(pi);
179 	}
180     }
181 }
182 
183 /*
184  * Scan the resource data in the node's data area for compatible device IDs
185  * and descriptions.
186  */
187 static void
biospnp_scanresdata(struct pnpinfo * pi,struct pnp_devNode * dn)188 biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn)
189 {
190     u_int	tag, i, rlen, dlen;
191     u_int8_t	*p;
192     char	*str;
193 
194     p = dn->dn_data;			/* point to resource data */
195     dlen = dn->dn_size - (p - (u_int8_t *)dn);	/* length of resource data */
196 
197     for (i = 0; i < dlen; i+= rlen) {
198 	tag = p[i];
199 	i++;
200 	if (PNP_RES_TYPE(tag) == 0) {
201 	    rlen = PNP_SRES_LEN(tag);
202 	    /* small resource */
203 	    switch (PNP_SRES_NUM(tag)) {
204 
205 	    case COMP_DEVICE_ID:
206 		/* got a compatible device ID */
207 		pnp_addident(pi, pnp_eisaformat(p + i));
208 		break;
209 
210 	    case END_TAG:
211 		return;
212 	    }
213 	} else {
214 	    /* large resource */
215 	    rlen = *(u_int16_t *)(p + i);
216 	    i += sizeof(u_int16_t);
217 
218 	    switch(PNP_LRES_NUM(tag)) {
219 
220 	    case ID_STRING_ANSI:
221 		str = malloc(rlen + 1);
222 		bcopy(p + i, str, rlen);
223 		str[rlen] = 0;
224 		if (pi->pi_desc == NULL) {
225 		    pi->pi_desc = str;
226 		} else {
227 		    free(str);
228 		}
229 		break;
230 	    }
231 	}
232     }
233 }
234 
235 
236 /*
237  * Make a 16-bit realmode PnP BIOS call.
238  *
239  * The first argument passed is the function number, the last is the
240  * BIOS data segment selector.  Intermediate arguments may be 16 or
241  * 32 bytes in length, and are described by the format string.
242  *
243  * Arguments to the BIOS functions must be packed on the stack, hence
244  * this evil.
245  */
246 static int
biospnp_call(int func,const char * fmt,...)247 biospnp_call(int func, const char *fmt, ...)
248 {
249     va_list	ap;
250     const char	*p;
251     uint8_t	*argp;
252     uint16_t	int16;
253     uint32_t	args[4];
254     uint32_t	i;
255 
256     /* function number first */
257     argp = (uint8_t *)args;
258     int16 = func;
259     bcopy(&int16, argp, sizeof (int16));
260     argp += sizeof(uint16_t);
261 
262     /* take args according to format */
263     va_start(ap, fmt);
264     for (p = fmt; *p != 0; p++) {
265 	switch(*p) {
266 	case 'w':
267 	    i = va_arg(ap, uint32_t);
268 	    int16 = i;
269 	    bcopy(&int16, argp, sizeof (int16));
270 	    argp += sizeof (uint16_t);
271 	    break;
272 
273 	case 'l':
274 	    i = va_arg(ap, uint32_t);
275 	    bcopy(&i, argp, sizeof (i));
276 	    argp += sizeof (uint32_t);
277 	    break;
278 	}
279     }
280     va_end(ap);
281 
282     /* BIOS segment last */
283     int16 = pnp_Icheck->pnp_rmds;
284     bcopy(&int16, argp, sizeof (int16));
285     argp += sizeof(uint16_t);
286 
287     /* prepare for call */
288     v86.ctl = V86_ADDR | V86_CALLF;
289     v86.addr = ((uint32_t)pnp_Icheck->pnp_rmcs << 16) + pnp_Icheck->pnp_rmip;
290 
291     /* call with packed stack and return */
292     v86bios(args[0], args[1], args[2], args[3]);
293     return (v86.eax & 0xffff);
294 }
295