add bad-apple

kernels/bad-apple/Makefile

@@ -0,0 +1,23 @@
+VIDEO_ROW = 25
+VIDEO_COL = 80
+AUDIO_FREQ = 44100
+AUDIO_CHANNEL = 1
+
+VIDEO_SRC = bad-apple.mp4
+VIDEO = build/video.frame
+AUDIO = build/audio.pcm
+
+NAME = bad-apple
+SRCS = bad-apple.c resources.S
+include $(AM_HOME)/Makefile
+
+CFLAGS  += -DVIDEO_ROW=$(VIDEO_ROW) -DVIDEO_COL=$(VIDEO_COL) \
+           -DAUDIO_FREQ=$(AUDIO_FREQ) -DAUDIO_CHANNEL=$(AUDIO_CHANNEL)
+ASFLAGS += -DVIDEO_FILE=\"$(abspath $(VIDEO))\" -DAUDIO_FILE=\"$(abspath $(AUDIO))\"
+$(VIDEO):
+	ffmpeg -i $(VIDEO_SRC) -f image2pipe -s $(VIDEO_COL)x$(VIDEO_ROW) -vcodec rawvideo -pix_fmt monow $@
+
+$(AUDIO):
+	ffmpeg -i $(VIDEO_SRC) -vn -acodec pcm_s16le -f s16le -ac $(AUDIO_CHANNEL) -ar $(AUDIO_FREQ) $@
+
+resources.S: $(VIDEO) $(AUDIO)

kernels/bad-apple/bad-apple.c

@@ -0,0 +1,74 @@
+#include <am.h>
+#include <stdio.h>
+#include <klib-macros.h>
+
+#define FPS 30
+#define CHAR_WHITE '.'
+#define CHAR_BLACK 'X'
+
+typedef struct {
+  uint8_t pixel[VIDEO_ROW * VIDEO_COL / 8];
+} frame_t;
+
+static void sleep_until(uint64_t next) {
+  while (io_read(AM_TIMER_UPTIME).us < next) ;
+}
+
+static uint8_t getbit(uint8_t *p, int idx) {
+  int byte_idx = idx / 8;
+  int bit_idx = idx % 8;
+  bit_idx = 7 - bit_idx;
+  uint8_t byte = p[byte_idx];
+  uint8_t bit = (byte >> bit_idx) & 1;
+  return bit;
+}
+
+int main() {
+  extern uint8_t video_payload, video_payload_end;
+  extern uint8_t audio_payload, audio_payload_end;
+  int audio_len = 0, audio_left = 0;
+  Area sbuf;
+
+  ioe_init();
+
+  frame_t *f = (void *)&video_payload;
+  frame_t *fend = (void *)&video_payload_end;
+  printf("\033[H\033[J");  // screan_clear
+
+  bool has_audio = io_read(AM_AUDIO_CONFIG).present;
+  if (has_audio) {
+    io_write(AM_AUDIO_CTRL, AUDIO_FREQ, AUDIO_CHANNEL, 1024);
+    audio_left = audio_len = &audio_payload_end - &audio_payload;
+    sbuf.start = &audio_payload;
+  }
+  
+  uint64_t now = io_read(AM_TIMER_UPTIME).us;
+  for (; f < fend; f ++) {
+     printf("\033[0;0H");  // reset cursor
+     for (int y = 0; y < VIDEO_ROW; y++) {
+       for (int x = 0; x < VIDEO_COL; x++) {
+         uint8_t p = getbit(f->pixel, y * VIDEO_COL + x);
+         putch(p ? CHAR_BLACK : CHAR_WHITE);
+       }
+       putch('\n');
+     }
+
+     if (has_audio) {
+       int should_play = (AUDIO_FREQ / FPS) * sizeof(int16_t);
+       if (should_play > audio_left) should_play = audio_left;
+       while (should_play > 0) {
+         int len = (should_play > 4096 ? 4096 : should_play);
+         sbuf.end = sbuf.start + len;
+         io_write(AM_AUDIO_PLAY, sbuf);
+         sbuf.start += len;
+         should_play -= len;
+       }
+       audio_left -= should_play;
+     }
+
+     uint64_t next = now + (1000 * 1000 / FPS);
+     sleep_until(next);
+     now = next;
+  }
+  return 0;
+}

kernels/bad-apple/resources.S

@@ -0,0 +1,12 @@
+.section .data
+.global video_payload, video_payload_end
+.p2align 3
+video_payload:
+.incbin VIDEO_FILE
+video_payload_end:
+
+.global audio_payload, audio_payload_end
+.p2align 3
+audio_payload:
+.incbin AUDIO_FILE
+audio_payload_end: