diff options
Diffstat (limited to 'sw/z80/kernel/memory.c')
| -rw-r--r-- | sw/z80/kernel/memory.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/sw/z80/kernel/memory.c b/sw/z80/kernel/memory.c index bcda3c3..cda62ca 100644 --- a/sw/z80/kernel/memory.c +++ b/sw/z80/kernel/memory.c @@ -1,13 +1,13 @@ #include "memory.h" -struct page pages_table[PAGES_MAX_COUNT]; +static 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) { + if (pages_table[i].pid != 0) { // write to mmu table } } @@ -15,18 +15,37 @@ int mmu_write_table(void) return 0; } +int page_new(void) +{ + int i, addr, used; + for (addr = ADDR_PAGE_FIRST; addr < ADDR_PAGE_LAST; addr += PAGE_SIZE) { + used = 0; + + for (i = 0; i < PAGES_MAX_COUNT; i++) { + if (page_map[i].addr == addr) { + used = 1; + break; + } + } + + if (!used) + return i; + } + + return -1; +} + int page_map(int page, int pid, uint16_t addr) { if (page >= PAGES_MAX_COUNT) return -1; - if (pages_table[page].used) + if (pages_table[page].pid != 0) return -2; pages_table[page].addr = addr; pages_table[page].pid = pid; - pages_table[page].used = 1; return 0; } @@ -35,10 +54,11 @@ int page_unmap(int page) if (page >= PAGES_MAX_COUNT) return -1; - if (pages_table[page].used == 0) + if (pages_table[page].pid == 0) return -2; - pages_table[page].used = 0; + pages_table[page].pid = 0; + pages_table[page].addr = 0; return 0; } |