From 84e104d83ef7a9c2929cab98b2658eb9860883cf Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Tue, 2 Nov 2021 21:47:05 +0100
Subject: [PATCH] Implement some basic syscall

---
 arch/x86/cpu_context.c              | 31 +++++++++++++++++++++++++++++
 core/syscall.c => arch/x86/swintr.c |  7 +------
 core/syscall.h => arch/x86/swintr.h |  1 +
 arch/x86/syscall_wrappers.S         |  4 ++--
 core/cpu_context.h                  | 12 +++++++++++
 core/thread.c                       |  1 +
 6 files changed, 48 insertions(+), 8 deletions(-)
 rename core/syscall.c => arch/x86/swintr.c (63%)
 rename core/syscall.h => arch/x86/swintr.h (98%)

diff --git a/arch/x86/cpu_context.c b/arch/x86/cpu_context.c
index 48697f9..b7a6fd6 100644
--- a/arch/x86/cpu_context.c
+++ b/arch/x86/cpu_context.c
@@ -489,3 +489,34 @@ void cpu_context_update_kernel_tss(struct cpu_state *next_ctxt)
      mode */
     }
 }
+
+
+inline
+int syscallGet3args(const struct cpu_state *user_ctxt,
+			       /* out */unsigned int *arg1,
+			       /* out */unsigned int *arg2,
+			       /* out */unsigned int *arg3)
+{
+  *arg1 = user_ctxt->ebx;
+  *arg2 = user_ctxt->ecx;
+  *arg3 = user_ctxt->edx;
+  return 0;
+}
+
+
+int syscallGet1arg(const struct cpu_state *user_ctxt,
+			      /* out */unsigned int *arg1)
+{
+  unsigned int unused;
+  return syscallGet3args(user_ctxt, arg1, & unused, & unused);
+}
+
+
+int _syscallGet2args(const struct cpu_state *user_ctxt,
+			       /* out */unsigned int *arg1,
+			       /* out */unsigned int *arg2)
+{
+  unsigned int unused;
+  return syscallGet3args(user_ctxt, arg1, arg2, & unused);
+}
+
diff --git a/core/syscall.c b/arch/x86/swintr.c
similarity index 63%
rename from core/syscall.c
rename to arch/x86/swintr.c
index 87976a0..d16d3e8 100644
--- a/core/syscall.c
+++ b/arch/x86/swintr.c
@@ -1,4 +1,4 @@
-#include "syscall.h"
+#include "swintr.h"
 #include "irq.h"
 #include "idt.h"
 
@@ -14,8 +14,3 @@ int syscallSetup(){
     return ret;
 }
 
-int syscall_execute(int syscallId, const struct cpu_state *user_ctx){
-    (void)syscallId;
-    (void)user_ctx;
-    return 0;
-}
diff --git a/core/syscall.h b/arch/x86/swintr.h
similarity index 98%
rename from core/syscall.h
rename to arch/x86/swintr.h
index 2b4a2be..2da6c00 100644
--- a/core/syscall.h
+++ b/arch/x86/swintr.h
@@ -2,4 +2,5 @@
 
 #define SYSCALL_INTR_NB  0x42
 
+
 int syscallSetup();
diff --git a/arch/x86/syscall_wrappers.S b/arch/x86/syscall_wrappers.S
index 06d2a9f..53e58cb 100644
--- a/arch/x86/syscall_wrappers.S
+++ b/arch/x86/syscall_wrappers.S
@@ -6,7 +6,7 @@
 .text
 
 /* The address of the real "C" syscall function */
-.extern syscall_execute
+.extern syscallExecute
 
 /** Update the kernel TSS in case we are switching to a thread in user
 	mode in order to come back into the correct kernel stack */
@@ -51,7 +51,7 @@ syscallHandler:
   pushl %esp /* user_ctxt */
   pushl %eax /* syscall ID */
 
-  call  syscall_execute
+  call  syscallExecute
   /* Unallocate the stack used by the
      do_syscall arguments */
   addl  $8, %esp
diff --git a/core/cpu_context.h b/core/cpu_context.h
index e17c31b..840179f 100644
--- a/core/cpu_context.h
+++ b/core/cpu_context.h
@@ -200,3 +200,15 @@ void cpu_state_detect_kernel_stack_overflow(const struct cpu_state *ctxt,
                                                                                     */})
 #define cpu_state_detect_kernel_stack_overflow(ctxt, stkbottom, stksize) ({/* nop */})
 #endif
+
+int syscallGet3args(const struct cpu_state *user_ctxt,
+                    /* out */ unsigned int *arg1,
+                    /* out */ unsigned int *arg2,
+                    /* out */ unsigned int *arg3);
+
+int syscallGet1arg(const struct cpu_state *user_ctxt,
+                   /* out */ unsigned int *arg1);
+
+int syscallGet2args(const struct cpu_state *user_ctxt,
+                    /* out */ unsigned int *arg1,
+                    /* out */ unsigned int *arg2);
diff --git a/core/thread.c b/core/thread.c
index 9fe7b24..fa31335 100644
--- a/core/thread.c
+++ b/core/thread.c
@@ -28,6 +28,7 @@ void threadExit()
     currentThread->state = EXITING;
     currentThread        = next;
     currentThread->state = RUNNING;
+    threadPrepareContext(next);
     cpu_context_exit_to(next->cpuState, (cpu_kstate_function_arg1_t *)threadDelete,
                         (uint32_t)current);