Syscall vector operational (for kernel mode)

include/asm.h

@@ -38,11 +38,6 @@
 //
 #define interrupt(n) asm volatile ("int %0" : : "N" (n) : "cc", "memory")
 
-//
-// Trigger a system call
-//
-#define syscall(n) asm volatile ("movq %0, %rdi\nint $0x80" : : "N" (n) : "cc", "memory")
-
 //
 // Returns whether IRQs are enabled
 //
@@ -75,6 +70,11 @@ extern void KeSendEOItoPIC(uchar isr);
 extern void KeEnableNMI(void);
 extern void KeDisableNMI(void);
 
+//
+// System Call
+//
+extern error_t KeSyscall(ulong code);
+
 //
 // Restore IRQ flag to its state before KePauseIRQs
 //

include/kernel/ke/syscall.h

@@ -33,7 +33,7 @@
 
 extern void KeJumpToUserspace(ulong args, void *entryPoint, void *stackAddr);
 
-void KeEnableSystemCalls();
+error_t _KeSyscallHandler(ulong code);
 
 //----------------------------------------------------------------------------//
 

kaleid/kernel/init/init.c

@@ -82,7 +82,6 @@ noreturn void BtStartKern(multiboot_info_t *mbInfo, uint mbMagic, void *codeSeg)
     MmActivatePageHandler();
     KeGetCpuInfos();
     IoEnableKeyb();
-    KeEnableSystemCalls();
 
     // ACPI
     IoInitAcpi();

kaleid/kernel/ke/cpuf.asm

@@ -26,6 +26,7 @@
 
 global divideByZero
 global KeActivateSSE
+global KeSyscall
 
 %include "kaleid/kernel/ke/cpuf.inc"
 
@@ -49,3 +50,10 @@ KeActivateSSE:
     mov cr4, rax
     pop rax
     ret
+
+;; 
+;;
+;;
+KeSyscall:
+    int 0x80
+    ret

kaleid/kernel/ke/cpuf.inc

@@ -69,6 +69,15 @@ isr%1:
     jmp isrPreHandler
 %endmacro
 
+%macro SyscallHandler 1
+global isr%1
+isr%1:
+    cli
+    push 0
+    push %1
+    jmp syscallPreHandler
+%endmacro
+
 %macro IsrWithErrCode 1
 global isr%1
 isr%1:

kaleid/kernel/ke/idt.c

@@ -74,7 +74,6 @@ static char *ExceptionsChar[32] = {
 static void EnablePIC(void);
 static void EarlyExceptionHandler(ISRFrame_t *regs);
 static void DoubleFaultHandler(ISRFrame_t *regs);
-static void EarlySyscallHandler(ISRFrame_t *regs);
 
 //
 // Registers an isr with his IRQ to handle driver interrupts
@@ -177,7 +176,7 @@ void KeSetupIDT(void)
     KeSetIDTGate(0x2F, (ulong)isr47, codeSeg, 0x8E, 3);
     
     // SYSCALL
-    KeSetIDTGate(0x80, (ulong)isr128, codeSeg, 0x8E, 3);
+    KeSetIDTGate(0x80, (ulong)isr128, codeSeg, 0x8E, 3); // Directly handled by _KeSyscallHandler, without registration
 
     KeIdtIsInitialized++;
 
@@ -188,7 +187,6 @@ void KeSetupIDT(void)
 
     KeRegisterISR(KeBrkDumpRegisters, 0x3);
     KeRegisterISR(DoubleFaultHandler, 0x8);
-    KeRegisterISR(EarlySyscallHandler, 0x80);
 
     // Load IDT
     KeLoadIDT();
@@ -391,11 +389,6 @@ static void DoubleFaultHandler(ISRFrame_t *regs)
     KeHaltCPU();
 }
 
-static void EarlySyscallHandler(ISRFrame_t *regs)
-{
-    DebugLog("Got an early system call !\n");
-}
-
 void KeBrkDumpRegisters(ISRFrame_t *regs)
 {
     IoDoBeepNoIdt();

kaleid/kernel/ke/isr.asm

@@ -30,6 +30,7 @@ global KeLoadIDT
 
 extern _KeIdtPtr
 extern _KeHandleISR
+extern _KeSyscallHandler
 
 ;;
 ;; Loads the IDT
@@ -99,6 +100,66 @@ Die:
     hlt
     jmp Die
 
+;;
+;; System call pre-handler
+;;
+syscallPreHandler:
+    pushAll
+    mov rax, cr8
+    push rax
+    mov rax, cr4
+    push rax
+    mov rax, cr3
+    push rax
+    mov rax, cr2
+    push rax
+    mov rax, cr0
+    push rax
+    mov rcx, 0xC0000080
+    rdmsr
+    push rax
+
+.SEnter:
+    ; Increment mask count as we configure all interrupts to mask IF
+    ;   automatically in the IDT
+    inc qword [gs:8]
+    ; Call the C routine for dispatching an interrupt
+    cld             ; DF must be cleared by the caller
+    mov rbp, 0      ; Terminate stack traces here
+
+    call _KeSyscallHandler
+
+    ; decrement mask count
+    dec qword [gs:8]
+    
+.SExit:
+    ; pop the control registers
+    add rsp, 48
+    pop rbx ; do not overwrite rax, so double pop on rbx
+    pop rbx
+    pop rcx
+    pop rdx
+    pop rsi
+    pop rdi
+    pop rbp
+    pop r8
+    pop r9
+    pop r10
+    pop r11
+    pop r12
+    pop r13
+    pop r14
+    pop r15
+
+    ; pop the error code and interrupt id
+    add rsp, 16
+
+    iretq
+
+Die2:
+    hlt
+    jmp Die
+
 ;; Divide Error Fault
 IsrWithoutErrCode 0
 
@@ -182,4 +243,4 @@ IsrWithoutErrCode 31
 %endrep
 
 ;; Syscall Vector
-IsrWithoutErrCode 128
+SyscallHandler 128

kaleid/kernel/ke/syscall.c

@@ -27,17 +27,9 @@
 #include <ke/idt.h>
 #include <io/vga.h>
 
-static uchar SyscallHandler(ISRFrame_t *regs)
+error_t _KeSyscallHandler(ulong code)
 {
-    DebugLog("Got a system call code %d !\n", regs->rdi);
+    DebugLog("Got a system call code %ld !\n", code);
     
     return EOK;
 }
-
-void KeEnableSystemCalls()
-{
-    ulong flags = KePauseIRQs();
-    KeRegisterISR(SyscallHandler, 0x80);
-    KeRestoreIRQs(flags);
-    KeEnableNMI();
-}

kaleid/kernel/sh/testcmds.c

@@ -314,9 +314,18 @@ error_t CmdTimerTest(int argc, char **argv, char *cmdline)
 
 error_t CmdSyscallTest(int argc, char **argv, char *cmdline)
 {
-    interrupt(0x80);
+    if (argc != 2) {
+        KernLog("Invalid arguments !\n");
+        return EINVAL;
+    }
 
-    return EOK;
+    ulong code = (ulong)atol(argv[1]);
+    
+    error_t err = KeSyscall(code);
+
+    KernLog("Exit : %s\n", strerror(err));
+    
+    return err;
 }
 
 error_t CmdRing3Test(int argc, char **argv, char *cmdline)