1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/sbi.c b/kernel/sbi.c
new file mode 100644
index 0000000..ff7556c
--- /dev/null
+++ b/kernel/sbi.c
@@ -0,0 +1,29 @@
+#include <fbos/compiler.h>
+#include <fbos/sbi.h>
+
+/* Implementation taken from the Linux kernel (6.12) */
+__kernel struct sbi_ret __sbi_ecall(unsigned long arg0, unsigned long arg1, unsigned long arg2,
+									unsigned long arg3, unsigned long arg4, unsigned long arg5,
+									int fid, int ext)
+{
+	struct sbi_ret ret;
+
+	register uintptr_t a0 asm("a0") = (uintptr_t)(arg0);
+	register uintptr_t a1 asm("a1") = (uintptr_t)(arg1);
+	register uintptr_t a2 asm("a2") = (uintptr_t)(arg2);
+	register uintptr_t a3 asm("a3") = (uintptr_t)(arg3);
+	register uintptr_t a4 asm("a4") = (uintptr_t)(arg4);
+	register uintptr_t a5 asm("a5") = (uintptr_t)(arg5);
+	register uintptr_t a6 asm("a6") = (uintptr_t)(fid);
+	register uintptr_t a7 asm("a7") = (uintptr_t)(ext);
+
+	asm volatile("ecall"
+				 : "+r"(a0), "+r"(a1)
+				 : "r"(a2), "r"(a3), "r"(a4), "r"(a5), "r"(a6), "r"(a7)
+				 : "memory");
+
+	ret.error = (long)a0;
+	ret.value = (long)a1;
+
+	return ret;
+}