kernel/amd64: Add syscall support + SYS_exit

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

3 files changed, 57 insertions, 0 deletions

diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c
index 7099cd2..b047dd8 100644
--- a/sys/arch/amd64/amd64/machdep.c
+++ b/sys/arch/amd64/amd64/machdep.c
@@ -44,6 +44,7 @@
 #endif
 
 int ibrs_enable(void);
+void syscall_isr(void);
 
 struct cpu_info g_bsp_ci = {0};
 static struct gdtr bsp_gdtr = {
@@ -66,6 +67,7 @@ setup_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_INT_GATE, ISR(syscall_isr), 0);
 }
 
 static inline void
diff --git a/sys/arch/amd64/amd64/syscall.S b/sys/arch/amd64/amd64/syscall.S
new file mode 100644
index 0000000..42ee242
--- /dev/null
+++ b/sys/arch/amd64/amd64/syscall.S
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <machine/frameasm.h>
+
+    .text
+    .globl syscall_isr
+INTRENTRY(syscall_isr, trap_syscall)
diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 2d479ee..7b866d8 100644
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -32,11 +32,14 @@
 #include <sys/reboot.h>
 #include <sys/panic.h>
 #include <sys/syslog.h>
+#include <sys/syscall.h>
 #include <machine/trap.h>
 #include <machine/frame.h>
 
 #define pr_error(fmt, ...) kprintf("trap: " fmt, ##__VA_ARGS__)
 
+void trap_syscall(struct trapframe *tf);
+
 static const char *trap_type[] = {
     [TRAP_BREAKPOINT]   = "breakpoint",
     [TRAP_ARITH_ERR]    = "arithmetic error",
@@ -83,6 +86,24 @@ regdump(struct trapframe *tf)
 }
 
 void
+trap_syscall(struct trapframe *tf)
+{
+    struct syscall_args scargs = {
+        .arg0 = tf->rdi,
+        .arg1 = tf->rsi,
+        .arg2 = tf->rdx,
+        .arg3 = tf->r10,
+        .arg4 = tf->r9,
+        .arg5 = 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)
 {
     if (tf->trapno >= NELEM(trap_type)) {