Initial commit

interrupt/interrupt.h

@@ -0,0 +1,74 @@
+#pragma once
+
+#include "../main.h"
+#include "stdbool.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+#define GDT_SIZE_BYTES 4
+#define GDT_EXEC       0x00AF9A000000FFFFull // Base=0, Limit=max, Access=Present|Ring0|TypeUser|Exec|Readable, Flag=GranularityPage|Long
+#define GDT_DATA       0x00EF92000000FFFFull // Base=0, Limit=max, Access=Present|Ring0|TypeUser|Writable, Flag=GranularityPage|Size
+#define GDT_EXEC_RING3 0x00AFFA000000FFFFull // Base=0, Limit=max, Access=Present|Ring3|TypeUser|Exec|Readable, Flag=GranularityPage|Long
+#define GDT_DATA_RING3 0x00EFF2000000FFFFull // Base=0, Limit=max, Access=Present|Ring3|TypeUser|Writable, Flag=GranularityPage|Size
+
+#define GDT_EXEC_SELECTOR       0x08 // SelectorIndex=1, TableIndicator=GDT(0), Privilege=Ring0
+#define GDT_DATA_SELECTOR       0x10 // SelectorIndex=2, TableIndicator=GDT(0), Privilege=Ring0
+#define GDT_EXEC_RING3_SELECTOR 0x1B // SelectorIndex=3, TableIndicator=GDT(0), Privilege=Ring3
+#define GDT_DATA_RING3_SELECTOR 0x23 // SelectorIndex=4, TableIndicator=GDT(0), Privilege=Ring3
+
+#define IDT_PRESENT (1ull << 47)
+#define IDT_RING0   0
+#define IDT_RING1   (1ull << 45)
+#define IDT_RING2   (2ull << 45)
+#define IDT_RING3   (3ull << 45)
+
+#define IDT_TYPE_32_CALL_GATE      (0x0Cull << 40)
+#define IDT_TYPE_32_INTERRUPT_GATE (0x0Eull << 40)
+#define IDT_TYPE_32_TRAP_GATE      (0x0Full << 40)
+
+typedef struct {
+	uint16_t length;
+	void *   base;
+} PACKED interrupt_DescriptorTableReference;
+// address of IDTR and GDTR, allocated by kMalloc() and is never freed
+extern interrupt_DescriptorTableReference *interrupt_IDTR, *interrupt_GDTR;
+
+// true if Init() has been called and interrupt handling is on
+extern bool interrupt_Enabled;
+
+// initializes interrupt handling like IDT and a dummy GDT
+void interrupt_Init();
+
+SYSV_ABI void interrupt_MapHandler(void *handler, int interrupt);
+
+
+// errorcode is 0 if nonexistent
+//
+// for IRQs, params are documented in assembly
+SYSV_ABI void interrupt_Handler(int vec, int errcode, uint64_t rip, int c, int d, int e);
+
+// defined in assembly
+SYSV_ABI void interrupt_LoadGDT(void *gdtr);
+SYSV_ABI void interrupt_LoadIDT(void *idtr);
+SYSV_ABI void interrupt_ReloadSegments();
+
+
+#define INTERRUPT_DISABLE                  \
+	uintptr_t __interrupt_flags;           \
+	asm volatile("pushf\n\tcli\n\tpop %0"  \
+				 : "=r"(__interrupt_flags) \
+				 :                         \
+				 : "memory")
+#define INTERRUPT_RESTORE                  \
+	asm volatile("push %0\n\tpopf"         \
+				 :                         \
+				 : "rm"(__interrupt_flags) \
+				 : "memory", "cc")
+
+
+#ifdef __cplusplus
+}
+#endif