3 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * Partly based on msbios.c from rolo 1.6:
26 *----------------------------------------------------------------------
28 * Sysgo Real-Time Solutions GmbH
29 * Klein-Winternheim, Germany
30 *----------------------------------------------------------------------
35 #include <asm/realmode.h>
38 DECLARE_GLOBAL_DATA_PTR;
42 #define BIOS_DATA ((char*)0x400)
43 #define BIOS_DATA_SIZE 256
44 #define BIOS_BASE ((char*)0xf0000)
45 #define BIOS_CS 0xf000
47 extern ulong __bios_start;
48 extern ulong __bios_size;
50 /* these are defined in a 16bit segment and needs
51 * to be accessed with the RELOC_16_xxxx() macros below
53 extern u16 ram_in_64kb_chunks;
54 extern u16 bios_equipment;
55 extern u8 pci_last_bus;
57 extern void *rm_int00;
58 extern void *rm_int01;
59 extern void *rm_int02;
60 extern void *rm_int03;
61 extern void *rm_int04;
62 extern void *rm_int05;
63 extern void *rm_int06;
64 extern void *rm_int07;
65 extern void *rm_int08;
66 extern void *rm_int09;
67 extern void *rm_int0a;
68 extern void *rm_int0b;
69 extern void *rm_int0c;
70 extern void *rm_int0d;
71 extern void *rm_int0e;
72 extern void *rm_int0f;
73 extern void *rm_int10;
74 extern void *rm_int11;
75 extern void *rm_int12;
76 extern void *rm_int13;
77 extern void *rm_int14;
78 extern void *rm_int15;
79 extern void *rm_int16;
80 extern void *rm_int17;
81 extern void *rm_int18;
82 extern void *rm_int19;
83 extern void *rm_int1a;
84 extern void *rm_int1b;
85 extern void *rm_int1c;
86 extern void *rm_int1d;
87 extern void *rm_int1e;
88 extern void *rm_int1f;
89 extern void *rm_def_int;
91 extern void *realmode_reset;
92 extern void *realmode_pci_bios_call_entry;
94 static int set_jmp_vector(int entry_point, void *target)
96 if (entry_point & ~0xffff) {
100 if (((u32)target-0xf0000) & ~0xffff) {
103 printf("set_jmp_vector: 0xf000:%04x -> %p\n",
104 entry_point, target);
107 writeb(0xea, 0xf0000 + entry_point);
110 writew(((u32)target-0xf0000), 0xf0000 + entry_point + 1);
113 writew(0xf000, 0xf0000 + entry_point + 3);
120 ************************************************************
121 * Install an interrupt vector
122 ************************************************************
125 static void setvector(int vector, u16 segment, void *handler)
127 u16 *ptr = (u16*)(vector*4);
128 ptr[0] = ((u32)handler - (segment << 4))&0xffff;
132 printf("setvector: int%02x -> %04x:%04x\n",
133 vector, ptr[1], ptr[0]);
137 #define RELOC_16_LONG(seg, off) *(u32*)(seg << 4 | (u32)&off)
138 #define RELOC_16_WORD(seg, off) *(u16*)(seg << 4 | (u32)&off)
139 #define RELOC_16_BYTE(seg, off) *(u8*)(seg << 4 | (u32)&off)
143 ulong bios_start = (ulong)&__bios_start + gd->reloc_off;
144 ulong bios_size = (ulong)&__bios_size;
149 struct pci_controller *pri_hose;
156 if (bios_size > 65536) {
157 printf("BIOS too large (%ld bytes, max is 65536)\n",
162 memcpy(BIOS_BASE, (void*)bios_start, bios_size);
165 memset(BIOS_DATA, 0, BIOS_DATA_SIZE);
167 /* enter some values to the bda */
168 writew(0x3f8, BIOS_DATA); /* com1 addr */
169 writew(0x2f8, BIOS_DATA+2); /* com2 addr */
170 writew(0x3e8, BIOS_DATA+4); /* com3 addr */
171 writew(0x2e8, BIOS_DATA+6); /* com4 addr */
172 writew(0x278, BIOS_DATA+8); /* lpt1 addr */
174 * The kernel wants to read the base memory size
175 * from 40:13. Put a zero there to avoid an error message
177 writew(0, BIOS_DATA+0x13); /* base memory size */
180 /* setup realmode interrupt vectors */
181 for (vector = 0; vector < NUMVECTS; vector++) {
182 setvector(vector, BIOS_CS, &rm_def_int);
185 setvector(0x00, BIOS_CS, &rm_int00);
186 setvector(0x01, BIOS_CS, &rm_int01);
187 setvector(0x02, BIOS_CS, &rm_int02);
188 setvector(0x03, BIOS_CS, &rm_int03);
189 setvector(0x04, BIOS_CS, &rm_int04);
190 setvector(0x05, BIOS_CS, &rm_int05);
191 setvector(0x06, BIOS_CS, &rm_int06);
192 setvector(0x07, BIOS_CS, &rm_int07);
193 setvector(0x08, BIOS_CS, &rm_int08);
194 setvector(0x09, BIOS_CS, &rm_int09);
195 setvector(0x0a, BIOS_CS, &rm_int0a);
196 setvector(0x0b, BIOS_CS, &rm_int0b);
197 setvector(0x0c, BIOS_CS, &rm_int0c);
198 setvector(0x0d, BIOS_CS, &rm_int0d);
199 setvector(0x0e, BIOS_CS, &rm_int0e);
200 setvector(0x0f, BIOS_CS, &rm_int0f);
201 setvector(0x10, BIOS_CS, &rm_int10);
202 setvector(0x11, BIOS_CS, &rm_int11);
203 setvector(0x12, BIOS_CS, &rm_int12);
204 setvector(0x13, BIOS_CS, &rm_int13);
205 setvector(0x14, BIOS_CS, &rm_int14);
206 setvector(0x15, BIOS_CS, &rm_int15);
207 setvector(0x16, BIOS_CS, &rm_int16);
208 setvector(0x17, BIOS_CS, &rm_int17);
209 setvector(0x18, BIOS_CS, &rm_int18);
210 setvector(0x19, BIOS_CS, &rm_int19);
211 setvector(0x1a, BIOS_CS, &rm_int1a);
212 setvector(0x1b, BIOS_CS, &rm_int1b);
213 setvector(0x1c, BIOS_CS, &rm_int1c);
214 setvector(0x1d, BIOS_CS, &rm_int1d);
215 setvector(0x1e, BIOS_CS, &rm_int1e);
216 setvector(0x1f, BIOS_CS, &rm_int1f);
218 set_jmp_vector(0xfff0, &realmode_reset);
219 set_jmp_vector(0xfe6e, &realmode_pci_bios_call_entry);
221 /* fill in data area */
222 RELOC_16_WORD(0xf000, ram_in_64kb_chunks) = gd->ram_size >> 16;
223 RELOC_16_WORD(0xf000, bios_equipment) = 0; /* FixMe */
225 /* If we assume only one PCI hose, this PCI hose
226 * will own PCI bus #0, and the last PCI bus of
227 * that PCI hose will be the last PCI bus in the
229 * (This, ofcause break on multi hose systems,
230 * but our PCI BIOS only support one hose anyway)
233 pri_hose = pci_bus_to_hose(0);
234 if (NULL != pri_hose) {
235 /* fill in last pci bus number for use by the realmode
237 RELOC_16_BYTE(0xf000, pci_last_bus) = pri_hose->last_busno;