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
|
// example of a simple memory allocation
// we use the mmap2 syscall for this
.text
// call mmap2
li a0, 0 // addr = 0, let OS choose address
li a1, 4096 // size
li a2, 3 // PROT_READ | PROT_WRITE
li a3, 5 // MAP_PRIVATE | MAP_ANONYMOUS
li a7, SCALL_MMAP2
ecall // invoke syscall
li t0, -1 // exit if unsuccessful
beq a0, t0, _exit
// print address
print.uhex a0
# we can look at the state of the mmu here:
ebreak
# > mmu.sections
# InstructionMemorySection[.text] at 0x00000100
# BinaryDataMemorySection[.stack] at 0x00000170
# BinaryDataMemorySection[.data.runtime-allocated] at 0x00080170
sw t0, 144(a0)
sw t0, 0(a0)
sw t0, 8(a0)
sw t0, 16(a0)
sw t0, 32(a0)
sw t0, 64(a0)
sw t0, 128(a0)
sw t0, 256(a0)
sw t0, 512(a0)
sw t0, 1024(a0)
sw t0, 2048(a0)
sw t0, 4000(a0)
lw t1, 128(a0)
print.uhex t0
ebreak
_exit:
li a7, 93
ecall
|
