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
|
/*=======================================================================================*/
/* This Sail RISC-V architecture model, comprising all files and */
/* directories except where otherwise noted is subject the BSD */
/* two-clause license in the LICENSE file. */
/* */
/* SPDX-License-Identifier: BSD-2-Clause */
/*=======================================================================================*/
/* Architectural state for the 'N' user-level interrupts standard extension. */
/* ustatus reveals a subset of mstatus */
bitfield Ustatus : xlenbits = {
UPIE : 4,
UIE : 0
}
/* This is a view, so there is no register defined. */
function lower_sstatus(s : Sstatus) -> Ustatus = {
let u = Mk_Ustatus(zero_extend(0b0));
let u = [u with UPIE = s[UPIE]];
let u = [u with UIE = s[UIE]];
u
}
function lift_ustatus(s : Sstatus, u : Ustatus) -> Sstatus = {
let s = [s with UPIE = u[UPIE]];
let s = [s with UIE = u[UIE]];
s
}
function legalize_ustatus(m : Mstatus, v : xlenbits) -> Mstatus = {
let u = Mk_Ustatus(v);
let s = lower_mstatus(m); // lower current mstatus to sstatus
let s = lift_ustatus(s, u); // get updated sstatus
let m = lift_sstatus(m, s); // lift it to an updated mstatus
m
}
bitfield Uinterrupts : xlenbits = {
UEI : 8, /* external interrupt */
UTI : 4, /* timer interrupt */
USI : 0 /* software interrupt */
}
/* Provides the uip read view of sip (s) as delegated by sideleg (d). */
function lower_sip(s : Sinterrupts, d : Sinterrupts) -> Uinterrupts = {
let u : Uinterrupts = Mk_Uinterrupts(zero_extend(0b0));
let u = [u with UEI = s[UEI] & d[UEI]];
let u = [u with UTI = s[UTI] & d[UTI]];
let u = [u with USI = s[USI] & d[USI]];
u
}
/* Provides the uie read view of sie as delegated by sideleg. */
function lower_sie(s : Sinterrupts, d : Sinterrupts) -> Uinterrupts = {
let u : Uinterrupts = Mk_Uinterrupts(zero_extend(0b0));
let u = [u with UEI = s[UEI] & d[UEI]];
let u = [u with UTI = s[UTI] & d[UTI]];
let u = [u with USI = s[USI] & d[USI]];
u
}
/* Returns the new value of sip from the previous sip (o) and the written uip (u) as delegated by sideleg (d). */
function lift_uip(o : Sinterrupts, d : Sinterrupts, u : Uinterrupts) -> Sinterrupts = {
let s : Sinterrupts = o;
let s = if d[USI] == 0b1 then [s with USI = u[USI]] else s;
s
}
function legalize_uip(s : Sinterrupts, d : Sinterrupts, v : xlenbits) -> Sinterrupts = {
lift_uip(s, d, Mk_Uinterrupts(v))
}
/* Returns the new value of sie from the previous sie (o) and the written uie (u) as delegated by sideleg (d). */
function lift_uie(o : Sinterrupts, d : Sinterrupts, u : Uinterrupts) -> Sinterrupts = {
let s : Sinterrupts = o;
let s = if d[UEI] == 0b1 then [s with UEI = u[UEI]] else s;
let s = if d[UTI] == 0b1 then [s with UTI = u[UTI]] else s;
let s = if d[USI] == 0b1 then [s with USI = u[USI]] else s;
s
}
function legalize_uie(s : Sinterrupts, d : Sinterrupts, v : xlenbits) -> Sinterrupts = {
lift_uie(s, d, Mk_Uinterrupts(v))
}
register utvec : Mtvec
register uscratch : xlenbits
register uepc : xlenbits
register ucause : Mcause
register utval : xlenbits
|
