Add lcdbench

README.md

@@ -6,6 +6,7 @@
  - [read_keys_SH3.py](read_keys_SH3.py) Scan key matrix and return key name(deprecated)
  - [read_keys_SH3.c](read_keys_SH3.c) Scan key matrix and return key name rewritten with C. nice performance
  - [x1](x1) Executable to analyze `[JHSBA]1` gen
+ - [lcdbench](lcdbench) Benchmark fb0 fill and show results
 
 
 ### License

lcdbench/Makefile

@@ -0,0 +1,11 @@
+CC?=arm-linux-gnueabi-gcc
+
+all: lcdbench
+
+.PHONY:
+clean:
+	rm -f lcdbench
+
+lcdbench: lcdbench.c
+	$(CC) $< -o $@
+

lcdbench/lcdbench.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <time.h>
+
+const int width = 800;
+const int height = 480;
+
+// 1 loop = 2 draws
+// 30 loop = 60 draws = 1 sec (60 fps)
+const int nloop = 30 * 3;
+
+struct timespec diff(struct timespec start, struct timespec end);
+
+int main(void) {
+	FILE *f;
+	uint16_t buf1[width * height];  //RGB565
+	uint16_t buf2[width * height];
+	struct timespec ts1, ts2, d;
+	int i, j;
+	float elapsed;
+
+	for (i = 0; i < height; i++) {
+		for (j = 0; j < width; j++) {
+			buf1[i * width + j] = (i << 8) + j;
+			buf2[i * width + j] = ~((i << 8) + j);
+		}
+	}
+
+	f = fopen("/dev/fb0", "w");
+	if (f == NULL) {
+		printf("Could not open /dev/fb0\n");
+		return 1;
+	}
+
+	clock_gettime(CLOCK_MONOTONIC, &ts1);
+	for (j = 0; j < nloop; j++) {
+		fwrite(buf1, sizeof(buf1), 1, f);
+		fseek(f, 0, SEEK_SET);
+		fwrite(buf2, sizeof(buf2), 1, f);
+		fseek(f, 0, SEEK_SET);
+	}
+	clock_gettime(CLOCK_MONOTONIC, &ts2);
+
+	d = diff(ts1, ts2);
+	elapsed = (float)d.tv_sec + ((float)d.tv_nsec * 1e-9);
+	printf("Frames: %d\n", nloop * 2);
+	printf("Elapsed: %f\n", elapsed);
+	printf("Frames per second: %f\n", (float)(nloop * 2) / elapsed);
+}
+
+// https://www.guyrutenberg.com/2007/09/22/profiling-code-using-clock_gettime/
+struct timespec diff(struct timespec start, struct timespec end) {
+	struct timespec temp;
+	if ((end.tv_nsec-start.tv_nsec)<0) {
+		temp.tv_sec = end.tv_sec-start.tv_sec-1;
+		temp.tv_nsec = 1000000000+end.tv_nsec-start.tv_nsec;
+	} else {
+		temp.tv_sec = end.tv_sec-start.tv_sec;
+		temp.tv_nsec = end.tv_nsec-start.tv_nsec;
+	}
+	return temp;
+}