1 /*
2 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <gpxe/dhcp.h>
22 #include <pxeparent.h>
23 #include <pxe_api.h>
24 #include <pxe_types.h>
25 #include <pxe.h>
26
27 /** @file
28 *
29 * Call interface to parent PXE stack
30 *
31 */
32
33 /**
34 * Name PXE API call
35 *
36 * @v function API call number
37 * @ret name API call name
38 */
39 static inline __attribute__ (( always_inline )) const char *
pxeparent_function_name(unsigned int function)40 pxeparent_function_name ( unsigned int function ) {
41 switch ( function ) {
42 case PXENV_START_UNDI:
43 return "PXENV_START_UNDI";
44 case PXENV_STOP_UNDI:
45 return "PXENV_STOP_UNDI";
46 case PXENV_UNDI_STARTUP:
47 return "PXENV_UNDI_STARTUP";
48 case PXENV_UNDI_CLEANUP:
49 return "PXENV_UNDI_CLEANUP";
50 case PXENV_UNDI_INITIALIZE:
51 return "PXENV_UNDI_INITIALIZE";
52 case PXENV_UNDI_RESET_ADAPTER:
53 return "PXENV_UNDI_RESET_ADAPTER";
54 case PXENV_UNDI_SHUTDOWN:
55 return "PXENV_UNDI_SHUTDOWN";
56 case PXENV_UNDI_OPEN:
57 return "PXENV_UNDI_OPEN";
58 case PXENV_UNDI_CLOSE:
59 return "PXENV_UNDI_CLOSE";
60 case PXENV_UNDI_TRANSMIT:
61 return "PXENV_UNDI_TRANSMIT";
62 case PXENV_UNDI_SET_MCAST_ADDRESS:
63 return "PXENV_UNDI_SET_MCAST_ADDRESS";
64 case PXENV_UNDI_SET_STATION_ADDRESS:
65 return "PXENV_UNDI_SET_STATION_ADDRESS";
66 case PXENV_UNDI_SET_PACKET_FILTER:
67 return "PXENV_UNDI_SET_PACKET_FILTER";
68 case PXENV_UNDI_GET_INFORMATION:
69 return "PXENV_UNDI_GET_INFORMATION";
70 case PXENV_UNDI_GET_STATISTICS:
71 return "PXENV_UNDI_GET_STATISTICS";
72 case PXENV_UNDI_CLEAR_STATISTICS:
73 return "PXENV_UNDI_CLEAR_STATISTICS";
74 case PXENV_UNDI_INITIATE_DIAGS:
75 return "PXENV_UNDI_INITIATE_DIAGS";
76 case PXENV_UNDI_FORCE_INTERRUPT:
77 return "PXENV_UNDI_FORCE_INTERRUPT";
78 case PXENV_UNDI_GET_MCAST_ADDRESS:
79 return "PXENV_UNDI_GET_MCAST_ADDRESS";
80 case PXENV_UNDI_GET_NIC_TYPE:
81 return "PXENV_UNDI_GET_NIC_TYPE";
82 case PXENV_UNDI_GET_IFACE_INFO:
83 return "PXENV_UNDI_GET_IFACE_INFO";
84 /*
85 * Duplicate case value; this is a bug in the PXE specification.
86 *
87 * case PXENV_UNDI_GET_STATE:
88 * return "PXENV_UNDI_GET_STATE";
89 */
90 case PXENV_UNDI_ISR:
91 return "PXENV_UNDI_ISR";
92 case PXENV_GET_CACHED_INFO:
93 return "PXENV_GET_CACHED_INFO";
94 default:
95 return "UNKNOWN API CALL";
96 }
97 }
98
99 /**
100 * PXE parent parameter block
101 *
102 * Used as the paramter block for all parent PXE API calls. Resides in base
103 * memory.
104 */
105 static union u_PXENV_ANY __bss16 ( pxeparent_params );
106 #define pxeparent_params __use_data16 ( pxeparent_params )
107
108 /** PXE parent entry point
109 *
110 * Used as the indirection vector for all parent PXE API calls. Resides in
111 * base memory.
112 */
113 SEGOFF16_t __bss16 ( pxeparent_entry_point );
114 #define pxeparent_entry_point __use_data16 ( pxeparent_entry_point )
115
116 /**
117 * Issue parent PXE API call
118 *
119 * @v entry Parent PXE stack entry point
120 * @v function API call number
121 * @v params PXE parameter block
122 * @v params_len Length of PXE parameter block
123 * @ret rc Return status code
124 */
pxeparent_call(SEGOFF16_t entry,unsigned int function,void * params,size_t params_len)125 int pxeparent_call ( SEGOFF16_t entry, unsigned int function,
126 void *params, size_t params_len ) {
127 PXENV_EXIT_t exit;
128 int discard_b, discard_D;
129 int rc;
130
131 /* Copy parameter block and entry point */
132 assert ( params_len <= sizeof ( pxeparent_params ) );
133 memcpy ( &pxeparent_params, params, params_len );
134 memcpy ( &pxeparent_entry_point, &entry, sizeof ( entry ) );
135
136 /* Call real-mode entry point. This calling convention will
137 * work with both the !PXE and the PXENV+ entry points.
138 */
139 __asm__ __volatile__ ( REAL_CODE ( "pushw %%es\n\t"
140 "pushw %%di\n\t"
141 "pushw %%bx\n\t"
142 "lcall *pxeparent_entry_point\n\t"
143 "addw $6, %%sp\n\t" )
144 : "=a" ( exit ), "=b" ( discard_b ),
145 "=D" ( discard_D )
146 : "b" ( function ),
147 "D" ( __from_data16 ( &pxeparent_params ) )
148 : "ecx", "edx", "esi", "ebp" );
149
150 /* PXE API calls may rudely change the status of A20 and not
151 * bother to restore it afterwards. Intel is known to be
152 * guilty of this.
153 *
154 * Note that we will return to this point even if A20 gets
155 * screwed up by the parent PXE stack, because Etherboot always
156 * resides in an even megabyte of RAM.
157 */
158 gateA20_set();
159
160 /* Determine return status code based on PXENV_EXIT and
161 * PXENV_STATUS
162 */
163 if ( exit == PXENV_EXIT_SUCCESS ) {
164 rc = 0;
165 } else {
166 rc = -pxeparent_params.Status;
167 /* Paranoia; don't return success for the combination
168 * of PXENV_EXIT_FAILURE but PXENV_STATUS_SUCCESS
169 */
170 if ( rc == 0 )
171 rc = -EIO;
172 }
173
174 /* If anything goes wrong, print as much debug information as
175 * it's possible to give.
176 */
177 if ( rc != 0 ) {
178 SEGOFF16_t rm_params = {
179 .segment = rm_ds,
180 .offset = __from_data16 ( &pxeparent_params ),
181 };
182
183 DBG ( "PXEPARENT %s failed: %s\n",
184 pxeparent_function_name ( function ), strerror ( rc ) );
185 DBG ( "PXEPARENT parameters at %04x:%04x length "
186 "%#02zx, entry point at %04x:%04x\n",
187 rm_params.segment, rm_params.offset, params_len,
188 pxeparent_entry_point.segment,
189 pxeparent_entry_point.offset );
190 DBG ( "PXEPARENT parameters provided:\n" );
191 DBG_HDA ( rm_params, params, params_len );
192 DBG ( "PXEPARENT parameters returned:\n" );
193 DBG_HDA ( rm_params, &pxeparent_params, params_len );
194 }
195
196 /* Copy parameter block back */
197 memcpy ( params, &pxeparent_params, params_len );
198
199 return rc;
200 }
201
202