sw/z80/kernel/memory.c


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

#include "memory.h"

struct page pages_table[PAGES_MAX_COUNT];

int mmu_write_table(void)
{
    int i;

    for (i = 0; i < PAGES_MAX_COUNT; i++) {
        if (pages_table[i].used) {
            // write to mmu table
        }
    }

    return 0;
}

int page_map(int page, int pid, uint16_t addr)
{
    if (page >= PAGES_MAX_COUNT)
        return -1;

    if (pages_table[page].used)
        return -2;

    pages_table[page].addr = addr;
    pages_table[page].pid = pid;

    pages_table[page].used = 1;
    return 0;
}

int page_unmap(int page)
{
    if (page >= PAGES_MAX_COUNT)
        return -1;

    if (pages_table[page].used == 0)
        return -2;

    pages_table[page].used = 0;
    return 0;
}