xref: /freebsd/stand/i386/libi386/biospnp.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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 /*
28  * PnP BIOS enumerator.
29  */
30 
31 #include <stand.h>
32 #include <machine/stdarg.h>
33 #include <bootstrap.h>
34 #include <isapnp.h>
35 #include <btxv86.h>
36 
37 
38 static int	biospnp_init(void);
39 static void	biospnp_enumerate(void);
40 
41 struct pnphandler biospnphandler =
42 {
43     "PnP BIOS",
44     biospnp_enumerate
45 };
46 
47 struct pnp_ICstructure
48 {
49     uint8_t	pnp_signature[4];
50     uint8_t	pnp_version;
51     uint8_t	pnp_length;
52     uint16_t	pnp_BIOScontrol;
53     uint8_t	pnp_checksum;
54     uint32_t	pnp_eventflag;
55     uint16_t	pnp_rmip;
56     uint16_t	pnp_rmcs;
57     uint16_t	pnp_pmip;
58     uint32_t	pnp_pmcs;
59     uint8_t	pnp_OEMdev[4];
60     uint16_t	pnp_rmds;
61     uint32_t	pnp_pmds;
62 } __packed;
63 
64 struct pnp_devNode
65 {
66     uint16_t	dn_size;
67     uint8_t	dn_handle;
68     uint8_t	dn_id[4];
69     uint8_t	dn_type[3];
70     uint16_t	dn_attrib;
71     uint8_t	dn_data[1];
72 } __packed;
73 
74 struct pnp_isaConfiguration
75 {
76     uint8_t	ic_revision;
77     uint8_t	ic_nCSN;
78     uint16_t	ic_rdport;
79     uint16_t	ic_reserved;
80 } __packed;
81 
82 static struct pnp_ICstructure	*pnp_Icheck = NULL;
83 static uint16_t			pnp_NumNodes;
84 static uint16_t			pnp_NodeSize;
85 
86 static void	biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn);
87 static int	biospnp_call(int func, const char *fmt, ...);
88 
89 #define vsegofs(vptr)	(((uint32_t)VTOPSEG(vptr) << 16) + VTOPOFF(vptr))
90 
91 typedef void    v86bios_t(uint32_t, uint32_t, uint32_t, uint32_t);
92 v86bios_t	*v86bios = (v86bios_t *)v86int;
93 
94 #define	biospnp_f00(NumNodes, NodeSize)			biospnp_call(0x00, "ll", NumNodes, NodeSize)
95 #define biospnp_f01(Node, devNodeBuffer, Control)	biospnp_call(0x01, "llw", Node, devNodeBuffer, Control)
96 #define biospnp_f40(Configuration)			biospnp_call(0x40, "l", Configuration)
97 
98 /* PnP BIOS return codes */
99 #define PNP_SUCCESS			0x00
100 #define PNP_FUNCTION_NOT_SUPPORTED	0x80
101 
102 /*
103  * Initialisation: locate the PnP BIOS, test that we can call it.
104  * Returns nonzero if the PnP BIOS is not usable on this system.
105  */
106 static int
107 biospnp_init(void)
108 {
109     struct pnp_isaConfiguration	icfg;
110     char			*sigptr;
111     int				result;
112 
113     /* Search for the $PnP signature */
114     pnp_Icheck = NULL;
115     for (sigptr = PTOV(0xf0000); sigptr < PTOV(0xfffff); sigptr += 16)
116 	if (!bcmp(sigptr, "$PnP", 4)) {
117 	    pnp_Icheck = (struct pnp_ICstructure *)sigptr;
118 	    break;
119 	}
120 
121     /* No signature, no BIOS */
122     if (pnp_Icheck == NULL)
123 	return(1);
124 
125     /*
126      * Fetch the system table parameters as a test of the BIOS
127      */
128     result = biospnp_f00(vsegofs(&pnp_NumNodes), vsegofs(&pnp_NodeSize));
129     if (result != PNP_SUCCESS) {
130 	return(1);
131     }
132 
133     /*
134      * Look for the PnP ISA configuration table
135      */
136     result = biospnp_f40(vsegofs(&icfg));
137     switch (result) {
138     case PNP_SUCCESS:
139 	/* If the BIOS found some PnP devices, take its hint for the read port */
140 	if ((icfg.ic_revision == 1) && (icfg.ic_nCSN > 0))
141 	    isapnp_readport = icfg.ic_rdport;
142 	break;
143     case PNP_FUNCTION_NOT_SUPPORTED:
144 	/* The BIOS says there is no ISA bus (should we trust that this works?) */
145 	printf("PnP BIOS claims no ISA bus\n");
146 	isapnp_readport = -1;
147 	break;
148     }
149     return(0);
150 }
151 
152 static void
153 biospnp_enumerate(void)
154 {
155     uint8_t		Node;
156     struct pnp_devNode	*devNodeBuffer;
157     uint8_t		buffer[max(pnp_NodeSize, sizeof(*devNodeBuffer))];
158     int			result;
159     struct pnpinfo	*pi;
160     int			count;
161 
162     /* Init/check state */
163     if (biospnp_init())
164 	return;
165 
166     devNodeBuffer = (struct pnp_devNode *)buffer;
167     Node = 0;
168     count = 1000;
169     while((Node != 0xff) && (count-- > 0)) {
170 	result = biospnp_f01(vsegofs(&Node), vsegofs(devNodeBuffer), 0x1);
171 	if (result != PNP_SUCCESS) {
172 	    printf("PnP BIOS node %d: error 0x%x\n", Node, result);
173 	} else {
174 	    pi = pnp_allocinfo();
175 	    pnp_addident(pi, pnp_eisaformat(devNodeBuffer->dn_id));
176 	    biospnp_scanresdata(pi, devNodeBuffer);
177 	    pnp_addinfo(pi);
178 	}
179     }
180 }
181 
182 /*
183  * Scan the resource data in the node's data area for compatible device IDs
184  * and descriptions.
185  */
186 static void
187 biospnp_scanresdata(struct pnpinfo *pi, struct pnp_devNode *dn)
188 {
189     u_int	tag, i, rlen, dlen;
190     uint8_t	*p;
191     char	*str;
192 
193     p = dn->dn_data;			/* point to resource data */
194     dlen = dn->dn_size - (p - (uint8_t *)dn);	/* length of resource data */
195 
196     for (i = 0; i < dlen; i+= rlen) {
197 	tag = p[i];
198 	i++;
199 	if (PNP_RES_TYPE(tag) == 0) {
200 	    rlen = PNP_SRES_LEN(tag);
201 	    /* small resource */
202 	    switch (PNP_SRES_NUM(tag)) {
203 
204 	    case COMP_DEVICE_ID:
205 		/* got a compatible device ID */
206 		pnp_addident(pi, pnp_eisaformat(p + i));
207 		break;
208 
209 	    case END_TAG:
210 		return;
211 	    }
212 	} else {
213 	    /* large resource */
214 	    rlen = *(uint16_t *)(p + i);
215 	    i += sizeof(uint16_t);
216 
217 	    switch(PNP_LRES_NUM(tag)) {
218 
219 	    case ID_STRING_ANSI:
220 		str = malloc(rlen + 1);
221 		bcopy(p + i, str, rlen);
222 		str[rlen] = 0;
223 		if (pi->pi_desc == NULL) {
224 		    pi->pi_desc = str;
225 		} else {
226 		    free(str);
227 		}
228 		break;
229 	    }
230 	}
231     }
232 }
233 
234 
235 /*
236  * Make a 16-bit realmode PnP BIOS call.
237  *
238  * The first argument passed is the function number, the last is the
239  * BIOS data segment selector.  Intermediate arguments may be 16 or
240  * 32 bytes in length, and are described by the format string.
241  *
242  * Arguments to the BIOS functions must be packed on the stack, hence
243  * this evil.
244  */
245 static int
246 biospnp_call(int func, const char *fmt, ...)
247 {
248     va_list	ap;
249     const char	*p;
250     uint8_t	*argp;
251     uint32_t	args[4];
252     uint32_t	i;
253 
254     /* function number first */
255     argp = (uint8_t *)args;
256     *(uint16_t *)argp = func;
257     argp += sizeof(uint16_t);
258 
259     /* take args according to format */
260     va_start(ap, fmt);
261     for (p = fmt; *p != 0; p++) {
262 	switch(*p) {
263 
264 	case 'w':
265 	    i = va_arg(ap, u_int);
266 	    *(uint16_t *)argp = i;
267 	    argp += sizeof(uint16_t);
268 	    break;
269 
270 	case 'l':
271 	    i = va_arg(ap, uint32_t);
272 	    *(uint32_t *)argp = i;
273 	    argp += sizeof(uint32_t);
274 	    break;
275 	}
276     }
277     va_end(ap);
278 
279     /* BIOS segment last */
280     *(uint16_t *)argp = pnp_Icheck->pnp_rmds;
281     argp += sizeof(uint16_t);
282 
283     /* prepare for call */
284     v86.ctl = V86_ADDR | V86_CALLF;
285     v86.addr = ((uint32_t)pnp_Icheck->pnp_rmcs << 16) + pnp_Icheck->pnp_rmip;
286 
287     /* call with packed stack and return */
288     v86bios(args[0], args[1], args[2], args[3]);
289     return(v86.eax & 0xffff);
290 }
291