diff --git a/arch/i386/dispatch.h b/arch/i386/dispatch.h
index 2237d612d650c42ce91ce5652e90cb50b4301a74..be55edd8a159313d9773bbfdac00f59690ef04d2 100644
--- a/arch/i386/dispatch.h
+++ b/arch/i386/dispatch.h
@@ -84,7 +84,7 @@ public:
/** \brief Syscall to start idle loop (in ring 0) */
static forceinline void idle(void) {
- syscall(&idle_loop, 0, true);
+ syscall<true>(&idle_loop);
}
/** \brief The idle loop
diff --git a/arch/i386/machine.cc b/arch/i386/machine.cc
index d1a65a8f1913afe24f44a99f32a240d94c196dc1..af8b063d02c3e8865e233bda05557f1381304791 100644
--- a/arch/i386/machine.cc
+++ b/arch/i386/machine.cc
@@ -11,6 +11,6 @@ noinline void __OS_trigger_syscall(uint8_t irq) {
}
void Machine::trigger_interrupt_from_user(uint8_t irq) {
- arch::syscall(__OS_trigger_syscall, irq, true);
+ arch::syscall<true>(__OS_trigger_syscall, irq);
}
diff --git a/arch/i386/syscall.cc b/arch/i386/syscall.cc
index 7a928150b0f0e0f6ca82d1432e566f9871559b3d..5ce6072d93c2cccdaa9939468298560d118e3152 100644
--- a/arch/i386/syscall.cc
+++ b/arch/i386/syscall.cc
@@ -15,10 +15,10 @@ namespace arch {
IRQ_HANDLER(IRQ_SYSCALL) {
// get arguments from registers
// also, store pointer to context in %esi before we change %esp
- uint32_t fun, arg;
+ uint32_t fun, arg1, arg2, arg3;
bool direct;
cpu_context* ctx;
- asm volatile("leal -4(%%esp), %0" : "=r"(ctx), "=c"(arg), "=b"(fun), "=d"(direct));
+ asm volatile("leal -4(%%esp), %0" : "=r"(ctx), "=c"(arg1), "=a"(arg2), "=D"(arg3), "=b"(fun), "=d"(direct));
// TODO: remove/reuse pushed CPU context?
@@ -42,13 +42,15 @@ IRQ_HANDLER(IRQ_SYSCALL) {
save_sp = 0; // for detecting bugs, not stricly neccessary
}
- // put syscall argument on top kernel stack
+ // put syscall arguments on top kernel stack
uint32_t* sp = (uint32_t*) (&_estack_os - 2048);
- *sp = arg;
+ *sp = arg3;
+ *(sp-1) = arg2;
+ *(sp-2) = arg1;
// push the syscall stack address/segment
Machine::push(GDT::USER_DATA_SEGMENT | 0x3); // push stack segment, DPL3
- Machine::push((uint32_t)(sp) - 4); // push stack pointer above argument
+ Machine::push((uint32_t)(sp-3)); // push stack pointer above argument
// push flags, IO privilege level 3
Machine::push(ctx->eflags | 0x3000);
@@ -74,7 +76,7 @@ IRQ_HANDLER(IRQ_SYSCALL) {
// call syscall function with argument
// C code does not work as compiler overwrites our return address with arg
//void (* f)(uint32_t) = (void (*)(uint32_t))fun; f(arg);
- asm volatile("push %0; call *%1; pop %0" :: "r"(arg), "r"(fun));
+ asm volatile("push %3; push %2; push %1; call *%0; pop %1; pop %2; pop %3" :: "r"(fun), "r"(arg1), "r"(arg2), "r"(arg3));
// restore page directory
asm volatile("mov %0, %%cr3" :: "S"(pd));
diff --git a/arch/i386/syscall.h b/arch/i386/syscall.h
index a21b9e8364f66b87810ae5c7af1fb20d01c73078..970732faf46e966cecce75ef592b8dff52c1daf1 100644
--- a/arch/i386/syscall.h
+++ b/arch/i386/syscall.h
@@ -13,29 +13,52 @@
namespace arch {
+/**@{*/
/** \brief Run specified function as syscall
*
* Currently, any function can be called this way. Eventually, this will be replaced
* by an (encoded) index to a static jumptable of syscalls
*
* \param fun syscall function to be called
- * \param arg (optional) argument for syscall
- * \param direct execute syscall directly in IRQ handler instead of userspace (default: false)
+ * \param arg1 (optional) argument for syscall
+ * \param arg2 (optional) argument for syscall
+ * \param arg3 (optional) argument for syscall
+ * \tparam direct execute syscall directly in IRQ handler instead of userspace (default: false)
*/
-template<typename F, typename A=int>
-forceinline void syscall(F fun, A arg=0, bool direct=false) {
- // save all registers and call syscall interrupt
- //asm volatile("pusha; int %0; popa" :: "i"(IRQ_SYSCALL), "b"(fun), "c"(*((uint32_t*)&arg)));
-
+template<bool direct=false, typename F>
+forceinline void syscall(F fun) {
// use clobber instead of pusha to save and restore only required registers:
// gcc documentation says to list modified input in outputs and they must not be included
// in clobber list, but LLVM works only the other way ...
- asm volatile("int %0" :: "i"(IRQ_SYSCALL), "b"(fun), "c"(*((uint32_t*)&arg)), "d"(direct) :
+ asm volatile("int %0" :: "i"(IRQ_SYSCALL), "b"(fun), "d"(direct) :
+ "ebx", "ecx", "eax", "edx", "ebp", "esi", "edi", "cc", "memory");
+}
+
+template<bool direct=false, typename F, typename A>
+forceinline void syscall(F fun, A arg1) {
+ asm volatile("int %0" :: "i"(IRQ_SYSCALL), "b"(fun), "c"(*((uint32_t*)&arg1)), "d"(direct) :
"ebx", "ecx", "eax", "edx", "ebp", "esi", "edi", "cc", "memory");
}
+template<bool direct=false, typename F, typename A, typename B>
+forceinline void syscall(F fun, A arg1, B arg2) {
+ asm volatile("int %0" :: "i"(IRQ_SYSCALL), "b"(fun), "c"(*((uint32_t*)&arg1)), "d"(direct),
+ "a"(*((uint32_t*)&arg2)) :
+ "ebx", "ecx", "eax", "edx", "ebp", "esi", "edi", "cc", "memory");
+}
+
+template<bool direct=false, typename F, typename A, typename B, typename C>
+forceinline void syscall(F fun, A arg1, B arg2, C arg3) {
+ asm volatile("int %0" :: "i"(IRQ_SYSCALL), "b"(fun), "c"(*((uint32_t*)&arg1)), "d"(direct),
+ "a"(*((uint32_t*)&arg2)), "D"(*((uint32_t*)&arg3)) :
+ "ebx", "ecx", "eax", "edx", "ebp", "esi", "edi", "cc", "memory");
+}
+
+/**@}*/
+
/** \brief Return true if calling code is running as part of a syscall */
forceinline bool in_syscall() {
+ // TODO: determine using some (encoded) system variable instead of hardware register?
return (LAPIC::get_task_prio() == 128);
}