lightbar: add seq type PROGRAM for user-programmable sequences

This diff allows the user to send small programs to the EC and
gain control of the lightbar. Right now, this is only exposed
through ectool, and sysfs support will come later.

To send a program to the EC, use
$ ectool lightbar program /path/to/program.bin
and then start running the program with
$ ectool lightbar seq program

BUG=None
BRANCH=ToT
TEST=Using the above steps with hand-assembled programs.
  Checked that infinite bytecode loops do not hang the EC.
  Checked that bad opcodes exit with an error.
  Stress tested pushing programs and changing sequences.

Signed-off-by: Eric Caruso <ejcaruso@chromium.org>
Change-Id: I635fb041a5dc5c403f7c26fb9a41b5563be9b6b7
Reviewed-on: https://chromium-review.googlesource.com/219558
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/extra/lightbar/main.c b/extra/lightbar/main.c
index 38234e743c..6014719f0b 100644
--- a/extra/lightbar/main.c
+++ b/extra/lightbar/main.c
@@ -290,3 +290,40 @@ done:
 	fclose(fp);
 	return r;
 }
+
+int lb_load_program(const char *filename, struct lb_program *prog)
+{
+	FILE *fp;
+	size_t got;
+	int rc;
+
+	fp = fopen(filename, "rb");
+	if (!fp) {
+		fprintf(stderr, "Can't open %s: %s\n",
+			filename, strerror(errno));
+		return 1;
+	}
+
+	rc = fseek(fp, 0, SEEK_END);
+	if (rc) {
+		fprintf(stderr, "Couldn't find end of file %s",
+				filename);
+		fclose(fp);
+		return 1;
+	}
+	rc = (int) ftell(fp);
+	if (rc > LB_PROG_LEN) {
+		fprintf(stderr, "File %s is too long, aborting\n", filename);
+		fclose(fp);
+		return 1;
+	}
+	rewind(fp);
+
+	memset(prog->data, 0, LB_PROG_LEN);
+	got = fread(prog->data, 1, LB_PROG_LEN, fp);
+	if (rc != got)
+		fprintf(stderr, "Warning: did not read entire file\n");
+	prog->size = got;
+	fclose(fp);
+	return 0;
+}