1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
#include "types.h"
#include "mp.h"
#include "defs.h"
#include "memlayout.h"
static struct _MP_* _mp_; /* The MP floating point structure */
static int ncpu;
static struct _MP_*
mp_scan(uint8_t *addr, int len)
{
uint8_t *e, *p, sum;
int i;
cprintf("scanning: 0x%x\n", (uint32_t)addr);
e = addr+len;
for(p = addr; p < e; p += sizeof(struct _MP_)){
if(memcmp(p, "_MP_", 4))
continue;
sum = 0;
for(i = 0; i < sizeof(struct _MP_); i++)
sum += p[i];
if(sum == 0)
return (struct _MP_ *)p;
}
return 0;
}
static struct _MP_*
mp_search(void)
{
uint8_t *bda;
uint32_t p;
struct _MP_ *mp;
/*
* Search for the MP Floating Pointer Structure, which according to the
* spec is in one of the following three locations:
* 1) in the first KB of the EBDA;
* 2) in the last KB of system base memory;
* 3) in the BIOS ROM between 0xE0000 and 0xFFFFF.
*/
bda = KADDR(0x400);
if((p = (bda[0x0F]<<8)|bda[0x0E])){
if((mp = mp_scan(KADDR(p), 1024)))
return mp;
}
else{
p = ((bda[0x14]<<8)|bda[0x13])*1024;
if((mp = mp_scan(KADDR(p-1024), 1024)))
return mp;
}
return mp_scan(KADDR(0xF0000), 0x10000);
}
static int
mp_detect(void)
{
struct PCMP *pcmp;
uint8_t *p, sum;
uint32_t length;
/*
* Search for an MP configuration table. For now,
* don't accept the default configurations (physaddr == 0).
* Check for correct signature, calculate the checksum and,
* if correct, check the version.
* To do: check extended table checksum.
*/
if((_mp_ = mp_search()) == 0 || _mp_->physaddr == 0)
return 1;
pcmp = KADDR(_mp_->physaddr);
if(memcmp(pcmp, "PCMP", 4))
return 2;
length = pcmp->length;
sum = 0;
for(p = (uint8_t*)pcmp; length; length--)
sum += *p++;
if(sum || (pcmp->version != 1 && pcmp->version != 4))
return 3;
cprintf("MP spec rev #: %x\n", _mp_->specrev);
return 0;
}
void
mpinit()
{
int r;
uint8_t *p, *e;
struct PCMP *pcmp;
ncpu = 0;
if ((r = mp_detect()) != 0) return;
cprintf ("This computer is multiprocessor!\n");
/*
* Run through the table saving information needed for starting
* application processors and initialising any I/O APICs. The table
* is guaranteed to be in order such that only one pass is necessary.
*/
pcmp = KADDR(_mp_->physaddr);
p = ((uint8_t*)pcmp)+sizeof(struct PCMP);
e = ((uint8_t*)pcmp)+pcmp->length;
while(p < e) {
switch(*p){
case PcmpPROCESSOR:
cprintf("a processor\n");
ncpu++;
p += sizeof(struct PCMPprocessor);
continue;
case PcmpBUS:
cprintf("a bus\n");
p += sizeof(struct PCMPbus);
continue;
case PcmpIOAPIC:
cprintf("an IO APIC\n");
p += sizeof(struct PCMPioapic);
continue;
case PcmpIOINTR:
cprintf("an IO interrupt assignment\n");
p += sizeof(struct PCMPintr);
continue;
default:
cprintf("mpinit: unknown PCMP type 0x%x (e-p 0x%x)\n", *p, e-p);
while(p < e){
cprintf("%uX ", *p);
p++;
}
break;
}
}
cprintf("ncpu: %d\n", ncpu);
}
|
