From 07fc5e2881f8e4c368866ba438d1a09d82760cbf Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Sat, 14 May 2016 22:15:44 +0200
Subject: [PATCH] disable syscall interface, HermitCore is a libOS...

---
 hermit/arch/x86/kernel/entry.asm   | 3 +++
 hermit/arch/x86/kernel/processor.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/hermit/arch/x86/kernel/entry.asm b/hermit/arch/x86/kernel/entry.asm
index aa19e351c..57cb2f4c2 100644
--- a/hermit/arch/x86/kernel/entry.asm
+++ b/hermit/arch/x86/kernel/entry.asm
@@ -384,6 +384,8 @@ extern finish_task_switch
 extern syscall_handler
 extern kernel_stack
 
+; libos => no syscall interface required
+%if 0
 global isrsyscall
 align 16
 ; used to realize system calls
@@ -457,6 +459,7 @@ isrsyscall:
     ; EFLAGS (and IF flag) will be restored by sysret
     ; sti
     o64 sysret
+%endif
 
 global switch_context
 align 16
diff --git a/hermit/arch/x86/kernel/processor.c b/hermit/arch/x86/kernel/processor.c
index 34b14348b..d669a10b7 100644
--- a/hermit/arch/x86/kernel/processor.c
+++ b/hermit/arch/x86/kernel/processor.c
@@ -438,6 +438,8 @@ int cpu_detection(void) {
 		kprintf("Set XCR0 to 0x%llx\n", xgetbv(0));
 	}
 
+	// libos => currently no support of syscalls
+#if 0
 	if (cpu_info.feature3 & CPU_FEATURE_SYSCALL) {
 		wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_LMA | EFER_LME | EFER_SCE);
 		wrmsr(MSR_STAR, (0x1BULL << 48) | (0x08ULL << 32));
@@ -445,6 +447,7 @@ int cpu_detection(void) {
 		//  clear IF flag during an interrupt
 		wrmsr(MSR_SYSCALL_MASK, EFLAGS_TF|EFLAGS_DF|EFLAGS_IF|EFLAGS_AC|EFLAGS_NT);
 	} else kputs("Processor doesn't support syscalls\n");
+#endif
 
 	if (has_nx())
 		wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NXE);