Add basic semihosting support.

1 files changed, 23 insertions, 0 deletions

diff --git a/util/semihosting.h b/util/semihosting.h
new file mode 100644
index 0000000..8d91737
--- /dev/null
+++ b/util/semihosting.h
@@ -0,0 +1,23 @@
+#ifndef SEMIHOSTING_H
+#define SEMIHOSTING_H
+
+#include <stdint.h>
+
+inline uint32_t semihosting_call(uint32_t num, const uint32_t* args = nullptr) {
+	register uint32_t a asm("r0") = num;
+	register uint32_t b asm("r1") = (uint32_t)args;
+	
+	asm volatile("bkpt 0xab" : "=r"(a) : "0"(a), "r"(b) : "memory");
+	
+	return a;
+}
+
+inline void semihosting_print(const void *buf) {
+	semihosting_call(0x04, (const uint32_t*)buf);
+}
+
+inline void semihosting_exit() {
+	semihosting_call(0x18);
+}
+
+#endif