os-workshop

commit 287dae4eb9d2945c6497426486676e5a8a0071f5
parent 8f4ca9f20812474b2a1ddad67296c89b920b1015
Author: Brian Swetland <swetland@frotz.net>
Date:   Thu, 12 May 2022 15:59:40 -0700

ex00-hello: hello world program

Diffstat:
A
example/ex00-hello.c
 | 
32
++++++++++++++++++++++++++++++++
A
project/ex00-hello.app.mk
 | 
6
++++++

2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/example/ex00-hello.c b/example/ex00-hello.c
@@ -0,0 +1,32 @@
+// Copyright 2022, Brian Swetland <swetland@frotz.net>
+// Licensed under the Apache License, Version 2.0
+
+#include <hw/riscv.h>
+#include <hw/context.h>
+#include <hw/debug.h>
+#include <hw/intrinsics.h>
+
+// if an exception occurs, dump register state and halt
+void exception_handler(eframe_t *ef) {
+	xprintf("\n** SUPERVISOR EXCEPTION **\n");
+	xprint_s_exception(ef);
+	xprintf("\nHALT\n");
+	for (;;) ;
+}
+
+// no interrupts to handle
+void interrupt_handler(void) {
+	xprintf("WAT?");
+	for (;;) ;
+}
+
+void start(void) {
+	xprintf("Example 00 - Hello\n");
+
+	// set trap vector to trap_entry() in trap-entry-single.S
+	// it will call exception_handler() or interrupt_handler()
+	csr_write(CSR_STVEC, (uintptr_t) trap_entry);
+
+	// this is illegal in supervisor mode
+	csr_write(CSR_MTVEC, 42);
+}
diff --git a/project/ex00-hello.app.mk b/project/ex00-hello.app.mk
@@ -0,0 +1,6 @@
+MOD_NAME := ex00-hello
+MOD_SRC := hw/src/start.S hw/src/trap-entry-single-stack.S
+MOD_SRC += example/ex00-hello.c
+MOD_SRC += hw/src/print-exception.c hw/src/debug-printf.c hw/src/debug-io.c
+MOD_LIB := c
+include make/app.mk