From 974eba39dfe2fe46f2fa2ce244c6425714e96bad Mon Sep 17 00:00:00 2001 From: Richard Qin Date: Sun, 8 Nov 2026 04:12:44 +0800 Subject: [mubios] Implement the PIC and PIT. Signed-off-by: Richard Qin --- mubios/drivers/pit.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 mubios/drivers/pit.c (limited to 'mubios/drivers/pit.c') diff --git a/mubios/drivers/pit.c b/mubios/drivers/pit.c new file mode 100644 index 0000000..4213940 --- /dev/null +++ b/mubios/drivers/pit.c @@ -0,0 +1,45 @@ +/* + RCC-Project + + Copyright (C) 2026 Richard Qin + + This file is part of RCC-Project. + + RCC-Project is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your option) any + later version. + + RCC-Project is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + A PARTICULAR PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along with + RCC-Project; see the file COPYING. If not see + . + */ + +#include "bios.h" +#include "io.h" + +#define PIT_COUNTER0 0x0040u +#define PIT_COMMAND 0x0043u + +#define PIT_SELECT_CHANNEL0 0x00u +#define PIT_ACCESS_WORD 0x30u +#define PIT_MODE_2 0x04u +#define PIT_BINARY 0x00u + +#define PIT_COMMAND_CHANNEL0_MODE2 \ + (PIT_SELECT_CHANNEL0 | PIT_ACCESS_WORD | PIT_MODE_2 | PIT_BINARY) + +void pit_init(void) +{ + io_out8 (PIT_COMMAND, PIT_COMMAND_CHANNEL0_MODE2); + + /* + * A divisor of zero represents 65536. + */ + io_out8 (PIT_COUNTER0, 0x00u); + io_out8 (PIT_COUNTER0, 0x00u); +} -- cgit v1.2.3