Initial version

Committed on the Free edition of March Hare Software CVSNT Server. Upgrade to CVS Suite for more features and support: http://march-hare.com/cvsnt/ git-svn-id: http://moon:8086/svn/vhdl/trunk@706 cc03376c-175c-47c8-b038-4cd826a8556b
2010-01-31 15:12:12 +00:00
parent 24490316aa
commit c49d7464fd
4 changed files with 408 additions and 0 deletions
@@ -0,0 +1,71 @@
+#include "libsys.h"
+#include "xcpt.h"
+
+/* 10 digits + 1 sign + 1 trailing nul */
+static char itoa_buf[12];
+
+char *itoa(int i)
+{
+	char *pos = itoa_buf + sizeof(itoa_buf) - 1;
+	unsigned int u;
+	int negative = 0;
+
+	if (i < 0)
+	{
+		negative = 1;
+		u = ((unsigned int)(-(1+i))) + 1;
+	}
+	else
+	{
+		u = i;
+	}
+
+	*pos = 0;
+
+	do
+	{
+		*--pos = '0' + (u % 10);
+		u /= 10;
+	} while (u);
+
+	if (negative)
+	{
+		*--pos = '-';
+	}
+
+	return pos;
+}
+
+int syscalls_handler(struct xcptcontext * xcp)
+{
+	int syscall_code;
+	char *pStr;
+
+	syscall_code = xcp->regs[2];
+
+	switch(syscall_code)
+	{
+		case 1:		// print integer
+		sputs(itoa(xcp->regs[4]));
+		break;
+
+		case 4:		// print string
+		pStr = (char*)xcp->regs[4];
+		sputs(pStr);
+		break;
+
+		default:
+		sputs("Unknown syscall (");print_word(syscall_code);sputs(") at ");print_word(xcp->epc);sputs("\n");
+		break;
+	}
+
+	xcp->epc += 4;	// set return address to instruction after syscall
+
+	return 0;
+}
+
+void syscalls_init(void)
+{
+	xcpt_register(Syscall, syscalls_handler);
+}
+