diff options
Diffstat (limited to 'mubios/drivers')
| -rw-r--r-- | mubios/drivers/ioapic.c | 87 | ||||
| -rw-r--r-- | mubios/drivers/pic.c | 18 | ||||
| -rw-r--r-- | mubios/drivers/pit.c | 11 |
3 files changed, 101 insertions, 15 deletions
diff --git a/mubios/drivers/ioapic.c b/mubios/drivers/ioapic.c new file mode 100644 index 0000000..98f2210 --- /dev/null +++ b/mubios/drivers/ioapic.c @@ -0,0 +1,87 @@ +/* + 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 + <http://www.gnu.org/licenses/>. + */ + +#include "bios.h" +#include "io.h" + +#define IOAPIC_INDEX 0xFEC00000u +#define IOAPIC_DATA 0xFEC00010u + +#define IOAPIC_IRQ0_LOW 0x10u +#define IOAPIC_IRQ0_HIGH 0x11u + +#define IOAPIC_IRQ0_EXTINT 0x00000700u + +#define IA32_APIC_BASE_MSR 0x0000001Bu +#define APIC_BASE 0xFEE00000u +#define APIC_SVR_OFFSET 0x000000F0u +#define APIC_LVT0_OFFSET 0x00000350u + +static volatile u32 *const ioapic_index = (volatile u32 *)IOAPIC_INDEX; + +static volatile u32 *const ioapic_data = (volatile u32 *)IOAPIC_DATA; + +static inline void +rdmsr (u32 msr, u32 *low, u32 *high) +{ + __asm__ volatile ("rdmsr" : "=a"(*low), "=d"(*high) : "c"(msr)); +} + +static inline void +wrmsr (u32 msr, u32 low, u32 high) +{ + __asm__ volatile ("wrmsr" : : "a"(low), "d"(high), "c"(msr)); +} + +static void +ioapic_write (u8 index, u32 value) +{ + *ioapic_index = index; + *ioapic_data = value; +} + +void +ioapic_init (void) +{ + u32 apic_base_low; + u32 apic_base_high; + + rdmsr (IA32_APIC_BASE_MSR, &apic_base_low, &apic_base_high); + + apic_base_low |= 0x00000800u; + wrmsr (IA32_APIC_BASE_MSR, apic_base_low, apic_base_high); + + /* + * Enable the local APIC. + */ + *(volatile u32 *)(APIC_BASE + APIC_SVR_OFFSET) = 0x000001FFu; + + /* + * Route legacy PIC interrupts through LVT0. + */ + *(volatile u32 *)(APIC_BASE + APIC_LVT0_OFFSET) = 0x00000700u; + + /* + * Route IOAPIC pin 0 to the legacy PIC ExtINT path. + */ + ioapic_write (IOAPIC_IRQ0_LOW, IOAPIC_IRQ0_EXTINT); + ioapic_write (IOAPIC_IRQ0_HIGH, 0x00000000u); +} diff --git a/mubios/drivers/pic.c b/mubios/drivers/pic.c index 099cee8..2144b6b 100644 --- a/mubios/drivers/pic.c +++ b/mubios/drivers/pic.c @@ -23,9 +23,9 @@ #include "io.h" #define PIC1_COMMAND 0x0020u -#define PIC1_DATA 0x0021u +#define PIC1_DATA 0x0021u #define PIC2_COMMAND 0x00A0u -#define PIC2_DATA 0x00A1u +#define PIC2_DATA 0x00A1u #define PIC_ICW1_INIT 0x11u #define PIC_ICW4_8086 0x01u @@ -36,30 +36,28 @@ #define PIC1_CASCADE_ID 0x04u #define PIC2_CASCADE_ID 0x02u -#define PIC1_MASK_DEFAULT 0xFBu +#define PIC1_MASK_DEFAULT 0xFAu #define PIC2_MASK_DEFAULT 0xFFu void pic_init (void) { io_out8 (PIC1_COMMAND, PIC_ICW1_INIT); - io_out8(PIC2_COMMAND, PIC_ICW1_INIT); + io_out8 (PIC2_COMMAND, PIC_ICW1_INIT); - io_out8(PIC1_DATA, PIC1_VECTOR_BASE); + io_out8 (PIC1_DATA, PIC1_VECTOR_BASE); io_out8 (PIC2_DATA, PIC2_VECTOR_BASE); - io_out8(PIC1_DATA, PIC1_CASCADE_ID); + io_out8 (PIC1_DATA, PIC1_CASCADE_ID); io_out8 (PIC2_DATA, PIC2_CASCADE_ID); - io_out8(PIC1_DATA, PIC_ICW4_8086); + io_out8 (PIC1_DATA, PIC_ICW4_8086); io_out8 (PIC2_DATA, PIC_ICW4_8086); /* * Keep the cascade line enabled. * All actual hardware IRQ lines remain masked. */ - io_out8(PIC1_DATA, PIC1_MASK_DEFAULT); + io_out8 (PIC1_DATA, PIC1_MASK_DEFAULT); io_out8 (PIC2_DATA, PIC2_MASK_DEFAULT); - } - diff --git a/mubios/drivers/pit.c b/mubios/drivers/pit.c index 4213940..69b3390 100644 --- a/mubios/drivers/pit.c +++ b/mubios/drivers/pit.c @@ -23,17 +23,18 @@ #include "io.h" #define PIT_COUNTER0 0x0040u -#define PIT_COMMAND 0x0043u +#define PIT_COMMAND 0x0043u #define PIT_SELECT_CHANNEL0 0x00u -#define PIT_ACCESS_WORD 0x30u -#define PIT_MODE_2 0x04u +#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) +void +pit_init (void) { io_out8 (PIT_COMMAND, PIT_COMMAND_CHANNEL0_MODE2); @@ -41,5 +42,5 @@ void pit_init(void) * A divisor of zero represents 65536. */ io_out8 (PIT_COUNTER0, 0x00u); - io_out8 (PIT_COUNTER0, 0x00u); + io_out8 (PIT_COUNTER0, 0x00u); } |