sandbox: Allow reading/writing of RAM buffer

It is useful to be able to save and restore the RAM contents of sandbox
U-Boot either for setting up tests, for later analysys, or for chaining
together multiple tests which need to keep the same memory contents.

Add a function to provide a memory file for U-Boot. This is read on
start-up and written when shutting down. If the file does not exist
on start-up, it will be created when shutting down.

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

1 files changed, 39 insertions, 0 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index ef6a651..725b505 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -399,3 +399,42 @@ void os_puts(const char *str)
 	while (*str)
 		os_putc(*str++);
 }
+
+int os_write_ram_buf(const char *fname)
+{
+	struct sandbox_state *state = state_get_current();
+	int fd, ret;
+
+	fd = open(fname, O_CREAT | O_WRONLY, 0777);
+	if (fd < 0)
+		return -ENOENT;
+	ret = write(fd, state->ram_buf, state->ram_size);
+	close(fd);
+	if (ret != state->ram_size)
+		return -EIO;
+
+	return 0;
+}
+
+int os_read_ram_buf(const char *fname)
+{
+	struct sandbox_state *state = state_get_current();
+	int fd, ret;
+	int size;
+
+	size = os_get_filesize(fname);
+	if (size < 0)
+		return -ENOENT;
+	if (size != state->ram_size)
+		return -ENOSPC;
+	fd = open(fname, O_RDONLY);
+	if (fd < 0)
+		return -ENOENT;
+
+	ret = read(fd, state->ram_buf, state->ram_size);
+	close(fd);
+	if (ret != state->ram_size)
+		return -EIO;
+
+	return 0;
+}