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| author | Freya Murphy <freya@freyacat.org> | 2025-04-20 19:56:27 -0400 |
|---|---|---|
| committer | Freya Murphy <freya@freyacat.org> | 2025-04-20 19:56:27 -0400 |
| commit | e03b2ed579e84967648796897bd8aaf4256319e9 (patch) | |
| tree | f3fa241a86b23e220945f502c7b0816bfb4a4826 /kernel/drivers/pit.c | |
| parent | fix term/gpu memory OOB error, add dynamic kernel identity map with N_IDENT_PTS (diff) | |
| download | comus-e03b2ed579e84967648796897bd8aaf4256319e9.tar.gz comus-e03b2ed579e84967648796897bd8aaf4256319e9.tar.bz2 comus-e03b2ed579e84967648796897bd8aaf4256319e9.zip | |
PIT (timer)
Diffstat (limited to 'kernel/drivers/pit.c')
| -rw-r--r-- | kernel/drivers/pit.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/drivers/pit.c b/kernel/drivers/pit.c new file mode 100644 index 0000000..cb3c091 --- /dev/null +++ b/kernel/drivers/pit.c @@ -0,0 +1,23 @@ +#include <comus/asm.h> +#include <comus/drivers/pit.h> + +#define CHAN_0 0x40 +#define CHAN_1 0x41 +#define CHAN_2 0x42 +#define CMD 0x43 + +uint64_t ticks = 0; + +uint16_t pit_read_divider(void) { + uint16_t count = 0; + cli(); + outb(CMD, 0); // clear bits + count = inb(CHAN_0); // low byte + count |= inb(CHAN_0)<<8; // highbyte + return count; +} + +void pit_set_divider(uint16_t count) { + outb(CHAN_0, count & 0xFF); // low byte + outb(CHAN_0, (count & 0xFF00) >> 8); // high byte +} |