1 files changed, 115 insertions, 0 deletions
diff --git a/fs/semihostingfs.c b/fs/semihostingfs.c
new file mode 100644
index 00000000000..96eb3349a2f
--- /dev/null
+++ b/fs/semihostingfs.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022, Sean Anderson <sean.anderson@seco.com>
+ * Copyright (c) 2012, Google Inc.
+ */
+
+#include <common.h>
+#include <fs.h>
+#include <malloc.h>
+#include <os.h>
+#include <semihosting.h>
+#include <semihostingfs.h>
+
+int smh_fs_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info)
+{
+	/*
+	 * Only accept a NULL struct blk_desc for the semihosting, which is when
+	 * hostfs interface is used
+	 */
+	return !!rbdd;
+}
+
+static int smh_fs_read_at(const char *filename, loff_t pos, void *buffer,
+			  loff_t maxsize, loff_t *actread)
+{
+	long fd, size, ret;
+
+	fd = smh_open(filename, MODE_READ | MODE_BINARY);
+	if (fd < 0)
+		return fd;
+	ret = smh_seek(fd, pos);
+	if (ret < 0) {
+		smh_close(fd);
+		return ret;
+	}
+	if (!maxsize) {
+		size = smh_flen(fd);
+		if (ret < 0) {
+			smh_close(fd);
+			return size;
+		}
+
+		maxsize = size;
+	}
+
+	size = smh_read(fd, buffer, maxsize);
+	smh_close(fd);
+	if (size < 0)
+		return size;
+
+	*actread = size;
+	return 0;
+}
+
+static int smh_fs_write_at(const char *filename, loff_t pos, void *buffer,
+			   loff_t towrite, loff_t *actwrite)
+{
+	long fd, size, ret;
+
+	fd = smh_open(filename, MODE_READ | MODE_BINARY | MODE_PLUS);
+	if (fd < 0)
+		return fd;
+	ret = smh_seek(fd, pos);
+	if (ret < 0) {
+		smh_close(fd);
+		return ret;
+	}
+
+	ret = smh_write(fd, buffer, towrite, &size);
+	smh_close(fd);
+	*actwrite = size;
+	return ret;
+}
+
+int smh_fs_size(const char *filename, loff_t *result)
+{
+	long fd, size;
+
+	fd = smh_open(filename, MODE_READ | MODE_BINARY);
+	if (fd < 0)
+		return fd;
+
+	size = smh_flen(fd);
+	smh_close(fd);
+
+	if (size < 0)
+		return size;
+
+	*result = size;
+	return 0;
+}
+
+int smh_fs_read(const char *filename, void *buf, loff_t offset, loff_t len,
+		loff_t *actread)
+{
+	int ret;
+
+	ret = smh_fs_read_at(filename, offset, buf, len, actread);
+	if (ret)
+		printf("** Unable to read file %s **\n", filename);
+
+	return ret;
+}
+
+int smh_fs_write(const char *filename, void *buf, loff_t offset,
+		 loff_t len, loff_t *actwrite)
+{
+	int ret;
+
+	ret = smh_fs_write_at(filename, offset, buf, len, actwrite);
+	if (ret)
+		printf("** Unable to write file %s **\n", filename);
+
+	return ret;
+}