2 files changed, 30 insertions, 4 deletions
diff --git a/arch/x86_64/src/context_switching/syscall/main.cpp b/arch/x86_64/src/context_switching/syscall/main.cpp
index 93fc613..996d7fb 100644
--- a/arch/x86_64/src/context_switching/syscall/main.cpp
+++ b/arch/x86_64/src/context_switching/syscall/main.cpp
@@ -2,7 +2,7 @@
 
 namespace teachos::arch::context_switching::syscall
 {
-  auto syscall(type syscall_number, arguments args) -> error
+  auto syscall(type syscall_number, arguments args) -> response
   {
     asm volatile("mov %[input], %%rax"
                  : /* no output from call */
@@ -18,9 +18,18 @@ namespace teachos::arch::context_switching::syscall
 
     asm volatile("syscall");
 
-    error error{};
-    asm volatile("mov %%rax, %[output]" : [output] "=m"(error));
-    return error;
+    error error_code{};
+    asm volatile("mov %%rax, %[output]" : [output] "=m"(error_code));
+
+    arguments values{};
+    asm volatile("mov %%rdi, %[output]" : [output] "=m"(values.arg_0));
+    asm volatile("mov %%rsi, %[output]" : [output] "=m"(values.arg_1));
+    asm volatile("mov %%rdx, %[output]" : [output] "=m"(values.arg_2));
+    asm volatile("mov %%r10, %[output]" : [output] "=m"(values.arg_3));
+    asm volatile("mov %%r8, %[output]" : [output] "=m"(values.arg_4));
+    asm volatile("mov %%r9, %[output]" : [output] "=m"(values.arg_5));
+
+    return {error_code, values};
   }
 
 }  // namespace teachos::arch::context_switching::syscall
diff --git a/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp b/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp
index da9eb1b..b88f273 100644
--- a/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp
+++ b/arch/x86_64/src/context_switching/syscall/syscall_handler.cpp
@@ -16,6 +16,20 @@ namespace teachos::arch::context_switching::syscall
       video::vga::text::newline();
       return error::OK;
     }
+
+    auto expand_user_heap() -> error
+    {
+      arguments args{};
+      asm volatile("mov %[input], %%rdi"
+                   : /* no output from call */
+                   : [input] "m"(args.arg_0)
+                   : "memory");
+      asm volatile("mov %[input], %%rsi"
+                   : /* no output from call */
+                   : [input] "m"(args.arg_1)
+                   : "memory");
+      return error::OUT_OF_MEMORY;
+    }
   }  // namespace
 
   auto syscall_handler() -> void
@@ -46,6 +60,9 @@ namespace teachos::arch::context_switching::syscall
       case type::WRITE:
         result = write_to_vga_buffer(arg_0);
         break;
+      case type::EXPAND_HEAP:
+        result = expand_user_heap();
+        break;
       default:
         teachos::arch::exception_handling::panic("[Syscall Handler] Invalid syscall number");
         break;