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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 <stdint.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <pxe.h>
25 #include <realmode.h>
26 #include <bios.h>
27 #include <pnpbios.h>
28 #include <basemem.h>
29 #include <gpxe/pci.h>
30 #include <undi.h>
31 #include <undirom.h>
32 #include <undiload.h>
33 
34 /** @file
35  *
36  * UNDI load/unload
37  *
38  */
39 
40 /** Parameter block for calling UNDI loader */
41 static struct s_UNDI_LOADER __bss16 ( undi_loader );
42 #define undi_loader __use_data16 ( undi_loader )
43 
44 /** UNDI loader entry point */
45 static SEGOFF16_t __bss16 ( undi_loader_entry );
46 #define undi_loader_entry __use_data16 ( undi_loader_entry )
47 
48 /**
49  * Call UNDI loader to create a pixie
50  *
51  * @v undi		UNDI device
52  * @v undirom		UNDI ROM
53  * @ret rc		Return status code
54  */
undi_load(struct undi_device * undi,struct undi_rom * undirom)55 int undi_load ( struct undi_device *undi, struct undi_rom *undirom ) {
56 	struct s_PXE ppxe;
57 	unsigned int fbms_seg;
58 	uint16_t exit;
59 	int rc;
60 
61 	/* Set up START_UNDI parameters */
62 	memset ( &undi_loader, 0, sizeof ( undi_loader ) );
63 	undi_loader.AX = undi->pci_busdevfn;
64 	undi_loader.BX = undi->isapnp_csn;
65 	undi_loader.DX = undi->isapnp_read_port;
66 	undi_loader.ES = BIOS_SEG;
67 	undi_loader.DI = find_pnp_bios();
68 
69 	/* Allocate base memory for PXE stack */
70 	undi->restore_fbms = get_fbms();
71 	fbms_seg = ( undi->restore_fbms << 6 );
72 	fbms_seg -= ( ( undirom->code_size + 0x0f ) >> 4 );
73 	undi_loader.UNDI_CS = fbms_seg;
74 	fbms_seg -= ( ( undirom->data_size + 0x0f ) >> 4 );
75 	undi_loader.UNDI_DS = fbms_seg;
76 
77 	/* Debug info */
78 	DBGC ( undi, "UNDI %p loading UNDI ROM %p to CS %04x DS %04x for ",
79 	       undi, undirom, undi_loader.UNDI_CS, undi_loader.UNDI_DS );
80 	if ( undi->pci_busdevfn != UNDI_NO_PCI_BUSDEVFN ) {
81 		unsigned int bus = ( undi->pci_busdevfn >> 8 );
82 		unsigned int devfn = ( undi->pci_busdevfn & 0xff );
83 		DBGC ( undi, "PCI %02x:%02x.%x\n",
84 		       bus, PCI_SLOT ( devfn ), PCI_FUNC ( devfn ) );
85 	}
86 	if ( undi->isapnp_csn != UNDI_NO_ISAPNP_CSN ) {
87 		DBGC ( undi, "ISAPnP(%04x) CSN %04x\n",
88 		       undi->isapnp_read_port, undi->isapnp_csn );
89 	}
90 
91 	/* Call loader */
92 	undi_loader_entry = undirom->loader_entry;
93 	__asm__ __volatile__ ( REAL_CODE ( "pushw %%ds\n\t"
94 					   "pushw %%ax\n\t"
95 					   "lcall *undi_loader_entry\n\t"
96 					   "addw $4, %%sp\n\t" )
97 			       : "=a" ( exit )
98 			       : "a" ( __from_data16 ( &undi_loader ) )
99 			       : "ebx", "ecx", "edx", "esi", "edi", "ebp" );
100 
101 	/* UNDI API calls may rudely change the status of A20 and not
102 	 * bother to restore it afterwards.  Intel is known to be
103 	 * guilty of this.
104 	 *
105 	 * Note that we will return to this point even if A20 gets
106 	 * screwed up by the UNDI driver, because Etherboot always
107 	 * resides in an even megabyte of RAM.
108 	 */
109 	gateA20_set();
110 
111 	if ( exit != PXENV_EXIT_SUCCESS ) {
112 		rc = -undi_loader.Status;
113 		if ( rc == 0 ) /* Paranoia */
114 			rc = -EIO;
115 		DBGC ( undi, "UNDI %p loader failed: %s\n",
116 		       undi, strerror ( rc ) );
117 		return rc;
118 	}
119 
120 	/* Populate PXE device structure */
121 	undi->pxenv = undi_loader.PXENVptr;
122 	undi->ppxe = undi_loader.PXEptr;
123 	copy_from_real ( &ppxe, undi->ppxe.segment, undi->ppxe.offset,
124 			 sizeof ( ppxe ) );
125 	undi->entry = ppxe.EntryPointSP;
126 	DBGC ( undi, "UNDI %p loaded PXENV+ %04x:%04x !PXE %04x:%04x "
127 	       "entry %04x:%04x\n", undi, undi->pxenv.segment,
128 	       undi->pxenv.offset, undi->ppxe.segment, undi->ppxe.offset,
129 	       undi->entry.segment, undi->entry.offset );
130 
131 	/* Update free base memory counter */
132 	undi->fbms = ( fbms_seg >> 6 );
133 	set_fbms ( undi->fbms );
134 	DBGC ( undi, "UNDI %p using [%d,%d) kB of base memory\n",
135 	       undi, undi->fbms, undi->restore_fbms );
136 
137 	return 0;
138 }
139 
140 /**
141  * Unload a pixie
142  *
143  * @v undi		UNDI device
144  * @ret rc		Return status code
145  *
146  * Erases the PXENV+ and !PXE signatures, and frees the used base
147  * memory (if possible).
148  */
undi_unload(struct undi_device * undi)149 int undi_unload ( struct undi_device *undi ) {
150 	static uint32_t dead = 0xdeaddead;
151 
152 	DBGC ( undi, "UNDI %p unloading\n", undi );
153 
154 	/* Erase signatures */
155 	if ( undi->pxenv.segment )
156 		put_real ( dead, undi->pxenv.segment, undi->pxenv.offset );
157 	if ( undi->ppxe.segment )
158 		put_real ( dead, undi->ppxe.segment, undi->ppxe.offset );
159 
160 	/* Free base memory, if possible */
161 	if ( undi->fbms == get_fbms() ) {
162 		DBGC ( undi, "UNDI %p freeing [%d,%d) kB of base memory\n",
163 		       undi, undi->fbms, undi->restore_fbms );
164 		set_fbms ( undi->restore_fbms );
165 		return 0;
166 	} else {
167 		DBGC ( undi, "UNDI %p leaking [%d,%d) kB of base memory\n",
168 		       undi, undi->fbms, undi->restore_fbms );
169 		return -EBUSY;
170 	}
171 }
172