kern: Add syscall entry and SYS_exit syscall

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

3 files changed, 28 insertions, 0 deletions

diff --git a/src/sys/arch/amd64/cpu/cpu_conf.c b/src/sys/arch/amd64/cpu/cpu_conf.c
index e462ef3..531f53b 100644
--- a/src/sys/arch/amd64/cpu/cpu_conf.c
+++ b/src/sys/arch/amd64/cpu/cpu_conf.c
@@ -36,6 +36,8 @@
 #include <machine/gdt.h>
 #include <string.h>
 
+extern void syscall_isr(void);
+
 /*
  * Initialize interrupt vectors
  */
@@ -54,6 +56,7 @@ init_vectors(void)
     idt_set_desc(0xC, IDT_TRAP_GATE, ISR(ss_fault), 0);
     idt_set_desc(0xD, IDT_TRAP_GATE, ISR(general_prot), 0);
     idt_set_desc(0xE, IDT_TRAP_GATE, ISR(page_fault), 0);
+    idt_set_desc(0x80, IDT_USER_GATE, ISR(syscall_isr), 0);
 }
 
 void
diff --git a/src/sys/arch/amd64/cpu/trap.S b/src/sys/arch/amd64/cpu/trap.S
index ef5c14f..6e4d58c 100644
--- a/src/sys/arch/amd64/cpu/trap.S
+++ b/src/sys/arch/amd64/cpu/trap.S
@@ -107,3 +107,9 @@ INTR_ENTRY(lapic_tmr_isr)
     mov %rsp, %rdi
     call md_sched_switch
 INTR_EXIT(lapic_tmr_isr)
+
+    .global syscall_isr
+INTR_ENTRY(syscall_isr)
+    mov %rsp, %rdi
+    call trap_syscall
+INTR_EXIT(syscall_isr)
diff --git a/src/sys/arch/amd64/cpu/trap.c b/src/sys/arch/amd64/cpu/trap.c
index 046263b..6ddc079 100644
--- a/src/sys/arch/amd64/cpu/trap.c
+++ b/src/sys/arch/amd64/cpu/trap.c
@@ -36,6 +36,7 @@
 #include <sys/cdefs.h>
 #include <sys/panic.h>
 #include <sys/syslog.h>
+#include <sys/syscall.h>
 #include <machine/trap.h>
 
 /*
@@ -146,6 +147,24 @@ trapframe_dump(struct trapframe *tf)
 }
 
 void
+trap_syscall(struct trapframe *tf)
+{
+    struct syscall_args scargs = {
+        .arg[0] = tf->rdi,
+        .arg[1] = tf->rsi,
+        .arg[2] = tf->rdx,
+        .arg[3] = tf->r10,
+        .arg[4] = tf->r9,
+        .arg[5] = tf->r8,
+        .tf = tf
+    };
+
+    if (tf->rax < MAX_SYSCALLS && tf->rax > 0) {
+        tf->rax = g_sctab[tf->rax](&scargs);
+    }
+}
+
+void
 trap_handler(struct trapframe *tf)
 {
     trapframe_dump(tf);