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#include "i386.h"
#include "Task.h"
#include "Syscall.h"
#include "Console.h"
extern "C" void syscall_entry();
extern "C" void syscall_ISR();
extern volatile RegisterDump* syscallRegDump;
asm(
".globl syscall_ISR \n"
".globl syscallRegDump \n"
"syscallRegDump: \n"
".long 0\n"
"syscall_ISR:\n"
" pusha\n"
" pushw %ds\n"
" pushw %es\n"
" pushw %fs\n"
" pushw %gs\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" pushw %ss\n"
" popw %ds\n"
" popw %es\n"
" popw %fs\n"
" popw %gs\n"
" mov %esp, syscallRegDump\n"
" call syscall_entry\n"
" popw %gs\n"
" popw %gs\n"
" popw %fs\n"
" popw %es\n"
" popw %ds\n"
" popa\n"
" iret\n"
);
static inline dword CAS(dword* mem, dword newval, dword oldval)
{
dword ret;
asm volatile(
"cmpxchgl %2, %1"
:"=a"(ret), "=m"(*mem)
:"r"(newval), "m"(*mem), "0"(oldval));
return ret;
}
class SpinLock {
public:
SpinLock()
{
}
~SpinLock()
{
unlock();
}
void lock()
{
volatile dword count = 0;
for (;;) {
if (CAS(&m_lock, 1, 0) == 1)
return;
++count;
}
if (count)
kprintf("waited %u in %s\n",count, current->name().characters());
}
void unlock()
{
// barrier();
m_lock = 0;
}
private:
dword m_lock { 0 };
};
class Locker {
public:
explicit Locker(SpinLock& l)
: m_lock(l)
{
m_lock.lock();
}
~Locker()
{
unlock();
}
void unlock()
{
m_lock.unlock();
}
private:
SpinLock& m_lock;
};
namespace Syscall {
static SpinLock* s_lock;
void initialize()
{
s_lock = new SpinLock;
registerUserCallableInterruptHandler(0x80, syscall_ISR);
kprintf("syscall: int 0x80 handler installed\n");
}
DWORD handle(DWORD function, DWORD arg1, DWORD arg2, DWORD arg3)
{
Locker locker(*s_lock);
switch (function) {
case Syscall::Yield:
yield();
break;
case Syscall::PutCharacter:
Console::the().putChar(arg1 & 0xff);
break;
case Syscall::Sleep:
//kprintf("syscall: sleep(%d)\n", arg1);
current->sys$sleep(arg1);
break;
case Syscall::Spawn:
return current->sys$spawn((const char*)arg1);
case Syscall::PosixOpen:
//kprintf("syscall: open('%s', %u)\n", arg1, arg2);
return current->sys$open((const char*)arg1, (size_t)arg2);
case Syscall::PosixClose:
//kprintf("syscall: close(%d)\n", arg1);
return current->sys$close((int)arg1);
case Syscall::PosixRead:
//kprintf("syscall: read(%d, %p, %u)\n", arg1, arg2, arg3);
return current->sys$read((int)arg1, (void*)arg2, (size_t)arg3);
case Syscall::PosixSeek:
// FIXME: This has the wrong signature, should be like lseek()
kprintf("syscall: seek(%d, %d)\n", arg1, arg2);
return current->sys$seek((int)arg1, (int)arg2);
case Syscall::PosixKill:
kprintf("syscall: kill(%d, %d)\n", arg1, arg2);
return current->sys$kill((pid_t)arg1, (int)arg2);
case Syscall::PosixGetuid:
return current->sys$getuid();
case Syscall::PosixGetgid:
return current->sys$getgid();
case Syscall::PosixGetpid:
return current->sys$getpid();
case Syscall::PosixExit:
cli();
locker.unlock();
current->sys$exit((int)arg1);
ASSERT_NOT_REACHED();
return 0;
default:
kprintf("int0x80: Unknown function %x requested {%x, %x, %x}\n", function, arg1, arg2, arg3);
break;
}
return 0;
}
}
void syscall_entry()
{
auto& regs = *syscallRegDump;
DWORD function = regs.eax;
DWORD arg1 = regs.edx;
DWORD arg2 = regs.ecx;
DWORD arg3 = regs.ebx;
regs.eax = Syscall::handle(function, arg1, arg2, arg3);
}
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