mos/x86_64: cpu: Add initial trap handling stubs

Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 301 insertions, 0 deletions

diff --git a/mos/sys/arch/x86_64/cpu/trap.c b/mos/sys/arch/x86_64/cpu/trap.c
new file mode 100644
index 0000000..bacf9c2
--- /dev/null
+++ b/mos/sys/arch/x86_64/cpu/trap.c
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2025, Ian Moffett.
+ * Provided under the BSD-3 clause.
+ */
+
+#include <kern/panic.h>
+#include <md/frame.h>
+
+/* Forward declaration */
+void trap_dispatch(TRAPFRAME *tf);
+
+void
+trap_dispatch(TRAPFRAME *tf)
+{
+    panic("fatal vector %x\n", tf->vector);
+}
diff --git a/mos/sys/arch/x86_64/cpu/vector.S b/mos/sys/arch/x86_64/cpu/vector.S
new file mode 100644
index 0000000..6d29afb
--- /dev/null
+++ b/mos/sys/arch/x86_64/cpu/vector.S
@@ -0,0 +1,214 @@
+/*
+ * Copyright (c) 2025, Ian Moffett.
+ * Provided under the BSD-3 clause.
+ */
+
+#include <md/idt.h>
+#include <md/kfence.h>
+
+    .macro set_trap vector, isr, ist
+        mov $\vector, %rdi
+        lea \isr(%rip), %rsi
+        mov $IDT_TRAP_GATE, %rdx
+        mov $\ist, %rcx
+        call md_idt_set_entry
+    .endm
+
+    .macro push_trapframe vector
+        .if \vector == 10 || \vector == 11 || \vector == 12 || \vector == 13 \
+            || \vector == 14
+            subq $8, %rsp
+        .endif
+
+        push %rax
+        push %rbx
+        push %rcx
+        push %rdx
+        push %rsi
+        push %rdi
+        push %rbp
+        push %r8
+        push %r9
+        push %r10
+        push %r11
+        push %r12
+        push %r13
+        push %r14
+        push %r15
+        push $\vector
+    .endm
+
+    .text
+    .globl md_set_vectors
+md_set_vectors:
+    push %r12
+    push %r13
+    push %r14
+    push %r15
+    push %rbx
+    push %rbp
+
+    set_trap 0x00, diverr, 0
+    set_trap 0x01, debug_except, 0
+    set_trap 0x02, nmi, 0
+    set_trap 0x03, breakpoint, 0
+    set_trap 0x04, overflow, 0
+    set_trap 0x05, bound_range, 0
+    set_trap 0x06, invalid_tss, 0
+    set_trap 0x07, no_coproc, 0
+    set_trap 0x08, double_fault, 0
+    set_trap 0x0A, invalid_tss, 0
+    set_trap 0x0B, seg_np, 0
+    set_trap 0x0C, ss_fault, 0
+    set_trap 0x0D, gpf, 0
+    set_trap 0x0E, page_fault, 0
+
+    pop %rbp
+    pop %rbx
+    pop %r15
+    pop %r14
+    pop %r13
+    pop %r12
+    retq
+
+    .align 8
+diverr:
+    KFENCE
+    push_trapframe 0x00
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+debug_except:
+    KFENCE
+    push_trapframe 0x1
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+nmi:
+    KFENCE
+    push_trapframe 0x2
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+breakpoint:
+    KFENCE
+    push_trapframe 0x3
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+overflow:
+    KFENCE
+    push_trapframe 0x4
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+bound_range:
+    KFENCE
+    push_trapframe 0x5
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+invl_opc:
+    KFENCE
+    push_trapframe 0x6
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+no_coproc:
+    KFENCE
+    push_trapframe 0x7
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE
+1:  cli
+    hlt
+    jmp 1b
+
+double_fault:
+    KFENCE_EC
+    push_trapframe 0x8
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+
+invalid_tss:
+    KFENCE_EC
+    push_trapframe 0xA
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+
+seg_np:
+    KFENCE_EC
+    push_trapframe 0xB
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+
+ss_fault:
+    KFENCE_EC
+    push_trapframe 0xC
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+
+gpf:
+    KFENCE_EC
+    push_trapframe 0xD
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+
+page_fault:
+    KFENCE_EC
+    push_trapframe 0xE
+    mov %rsp, %rdi
+    call trap_dispatch
+    KFENCE_EC
+1:  cli
+    hlt
+    jmp 1b
+    hlt
diff --git a/mos/sys/inc/arch/x86_64/frame.h b/mos/sys/inc/arch/x86_64/frame.h
new file mode 100644
index 0000000..5908d93
--- /dev/null
+++ b/mos/sys/inc/arch/x86_64/frame.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2025, Ian Moffett.
+ * Provided under the BSD-3 clause.
+ */
+
+#ifndef _MACHINE_FRAME_H_
+#define _MACHINE_FRAME_H_ 1
+
+#include <sdk/types.h>
+#include <sdk/defs.h>
+
+/*
+ * Processor state
+ */
+typedef struct {
+    UQUAD vector;
+    UQUAD r15;
+    UQUAD r14;
+    UQUAD r13;
+    UQUAD r12;
+    UQUAD r11;
+    UQUAD r10;
+    UQUAD r9;
+    UQUAD r8;
+    UQUAD rbp;
+    UQUAD rdi;
+    UQUAD rsi;
+    UQUAD rbx;
+    UQUAD rdx;
+    UQUAD rcx;
+    UQUAD rax;
+    UQUAD error_code;
+    UQUAD rip;
+    UQUAD cs;
+    UQUAD rflags;
+    UQUAD rsp;
+    UQUAD ss;
+} PACKED TRAPFRAME;
+
+#endif  /* !_MACHINE_FRAME_H_ */
diff --git a/mos/sys/inc/arch/x86_64/kfence.h b/mos/sys/inc/arch/x86_64/kfence.h
new file mode 100644
index 0000000..f44336c
--- /dev/null
+++ b/mos/sys/inc/arch/x86_64/kfence.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2025, Ian Moffett.
+ * Provided under the BSD-3 clause.
+ */
+
+#ifndef _MACHINE_KFENCE_H_
+#define _MACHINE_KFENCE_H_ 1
+
+/*
+ * Kernel fence for interrupt entries that do
+ * not have an error code
+ */
+#define KFENCE              \
+    testq $0x3, 8(%rsp)   ; \
+    jz 1f                 ; \
+    lfence                ; \
+    swapgs                ; \
+1:  nop
+
+/*
+ * Kernel fence for interrupt entries that
+ * have an error code
+ */
+#define KFENCE_EC           \
+    testq $0x3, 16(%rsp)  ; \
+    jz 1f                 ; \
+    lfence                ; \
+    swapgs                ; \
+1:  nop
+
+#endif  /* !_MACHINE_KFENCE_H_ */