exception changes

3 files changed, 132 insertions, 2 deletions

diff --git a/kc/core/cpu/cpu.c b/kc/core/cpu/cpu.c
index 6e8e8b6..28b69ff 100644
--- a/kc/core/cpu/cpu.c
+++ b/kc/core/cpu/cpu.c
@@ -257,8 +257,12 @@ void cpu_init(void)
 
 void exceptions_init(void)
 {
-    isr_install(GENERAL_PROTECTION_VECTOR, &general_protection_isr, 0, 0);
-    isr_install(PAGE_FAULT_VECTOR, &page_fault_isr, 0, 0);
+    isr_install(
+            GENERAL_PROTECTION_EXCEPTION,
+            &general_protection_isr,
+            0,
+            0);
+    isr_install(PAGE_FAULT_EXCEPTION, &page_fault_isr, 0, 0);
 }
 
 void isr_install(int vec, void (*isr)(void), int trap, unsigned ist)
diff --git a/kc/core/cpu/exceptions.S b/kc/core/cpu/exceptions.S
new file mode 100644
index 0000000..8a19c8c
--- /dev/null
+++ b/kc/core/cpu/exceptions.S
@@ -0,0 +1,85 @@
+#include "exceptions.h"
+
+.macro EXCEPTION_BEGIN vec:req, code=0
+    // just in case something tried to be clever before
+    cld
+    // push param registers
+    push %rdi
+    // store certain parameters
+    movb $\vec,%dil
+    push %rsi
+    .if \code
+    movq 16(%rsp), %rsi
+    .else
+    xor %rsi, %rsi
+    .endif
+    push %rdx
+    push %rcx
+    push %r8
+    push %r9
+    // caller-saved registers
+    push %rax
+    push %r10
+    push %r11
+    // callee-saved registers
+    push %rbx
+    push %rbp
+    push %r12
+    push %r13
+    push %r14
+    push %r15
+.endm
+
+.macro EXCEPTION_END vec:req, code=0
+    // restore all the registers
+    pop %r15
+    pop %r14
+    pop %r13
+    pop %r12
+    pop %rbp
+    pop %rbx
+    pop %r11
+    pop %r10
+    pop %rax
+    pop %r9
+    pop %r8
+    pop %rcx
+    pop %rdx
+    pop %rsi
+    pop %rdi
+    .if \code
+    add $8, %rsp
+    .endif
+    iretq
+.endm
+
+.macro EXCEPTION_CALL func
+    // align the stack for the call to the handler function
+    mov %rsp, %rbp
+    and $-16, %rsp
+    call \func
+    // restore stack pointer, possibly unaligned
+    mov %rbp, %rsp
+.endm
+
+.macro EXCEPTION_DEFINE name:req, vec:req
+\name\()_isr:
+    .if \vec > 9 && \vec < 15 || \vec == 17 || \vec == 21 || \vec > 28 && \vec < 31
+    EXCEPTION_BEGIN \vec, 1
+    .else
+    EXCEPTION_BEGIN \vec
+    .endif
+    EXCEPTION_CALL \name\()_handler
+    .if \vec > 9 && \vec < 15 || \vec == 17 || \vec == 21 || \vec > 28 && \vec < 31
+    EXCEPTION_END \vec, 1
+    .else
+    EXCEPTION_END \vec
+    .endif
+.size \name\()_isr, . - \name\()_isr
+.endm
+
+EXCEPTION_DECLARE page_fault PAGE_FAULT_EXCEPTION
+EXCEPTION_DECLARE general_protection GENERAL_PROTECTION_EXCEPTION
+EXCEPTION_DEFINE page_fault, PAGE_FAULT_EXCEPTION
+EXCEPTION_DEFINE general_protection, GENERAL_PROTECTION_EXCEPTION
+
diff --git a/kc/core/cpu/exceptions.h b/kc/core/cpu/exceptions.h
new file mode 100644
index 0000000..c35c8ca
--- /dev/null
+++ b/kc/core/cpu/exceptions.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#define DIVIDE_ZER0_EXCEPTION 0x0
+#define DEBUG_EXCEPTION 0x1
+#define NONMASKABLE_EXCEPTION 0x2
+#define BREAKPOINT_EXCEPTION 0x3
+#define OVERFLOW_EXCEPTION 0x4
+#define BOUND_RANGE_EXCEPTION 0x5
+#define INVALID_OPCODE_EXCEPTION 0x6
+#define DEVICE_NOT_AVAILABLE_EXCEPTION 0x7
+#define DOUBLE_FAULT_EXCEPTION 0x8
+#define INVALID_TSS_EXCEPTION 0x10
+#define SEGMENT_NOT_PRESENT_EXCEPTION 0x11
+#define STACK_EXCEPTION 0xc
+#define GENERAL_PROTECTION_EXCEPTION 0xd
+#define PAGE_FAULT_EXCEPTION 0xe
+#define X87_FLOAT_EXCEPTION 0x10
+#define ALIGNMENT_CHECK_EXCEPTION 0x11
+#define MACHINE_CHECK_EXCEPTION 0x12
+#define SIMD_FLOAT_EXCEPTION 0x13
+
+#ifndef __ASSEMBLER__
+
+void general_protection_isr();
+void general_protection_handler();
+void page_fault_isr();
+void page_fault_handler();
+
+void exceptions_init(void);
+
+#else
+
+.macro EXCEPTION_DECLARE name:req, vec:req
+.hidden \name\()_isr
+.global \name\()_isr
+.extern \name\()_handler
+.type \name\()_isr, @function
+.endm
+
+#endif
+