sandbox: Add a function to read a host file

Add a way to read a file from the host filesystem. This can be useful for
reading test data, for example. Also fix up the writing function which was
not the right version, and drop the debugging lines.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 41 insertions, 3 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 325ded51d8..3e0f4c30af 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -98,9 +98,8 @@ void os_exit(int exit_code)
 	exit(exit_code);
 }
 
-int os_write_file(const char *name, const void *buf, int size)
+int os_write_file(const char *fname, const void *buf, int size)
 {
-	char fname[256];
 	int fd;
 
 	fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT | OS_O_TRUNC);
@@ -110,14 +109,53 @@ int os_write_file(const char *name, const void *buf, int size)
 	}
 	if (os_write(fd, buf, size) != size) {
 		printf("Cannot write to file '%s'\n", fname);
+		os_close(fd);
 		return -EIO;
 	}
 	os_close(fd);
-	printf("Write '%s', size %#x (%d)\n", name, size, size);
 
 	return 0;
 }
 
+int os_read_file(const char *fname, void **bufp, int *sizep)
+{
+	off_t size;
+	int ret = -EIO;
+	int fd;
+
+	fd = os_open(fname, OS_O_RDONLY);
+	if (fd < 0) {
+		printf("Cannot open file '%s'\n", fname);
+		goto err;
+	}
+	size = os_lseek(fd, 0, OS_SEEK_END);
+	if (size < 0) {
+		printf("Cannot seek to end of file '%s'\n", fname);
+		goto err;
+	}
+	if (os_lseek(fd, 0, OS_SEEK_SET) < 0) {
+		printf("Cannot seek to start of file '%s'\n", fname);
+		goto err;
+	}
+	*bufp = os_malloc(size);
+	if (!*bufp) {
+		printf("Not enough memory to read file '%s'\n", fname);
+		ret = -ENOMEM;
+		goto err;
+	}
+	if (os_read(fd, *bufp, size) != size) {
+		printf("Cannot read from file '%s'\n", fname);
+		goto err;
+	}
+	os_close(fd);
+	*sizep = size;
+
+	return 0;
+err:
+	os_close(fd);
+	return ret;
+}
+
 /* Restore tty state when we exit */
 static struct termios orig_term;
 static bool term_setup;