X-Git-Url: http://sraa.de/git/?a=blobdiff_plain;f=minidol%2Flib%2Fports.c;fp=minidol%2Flib%2Fports.c;h=3ae1ece93645e2dfa5fc74324cddfabb129b13bd;hb=dea7a4fb1ed110d3ce6e6d9255103d724bd66c0e;hp=0000000000000000000000000000000000000000;hpb=3e30b001296fb059cb070498bbe5d8e8834cd3e3;p=jump.git

diff --git a/minidol/lib/ports.c b/minidol/lib/ports.c
new file mode 100644
index 0000000..3ae1ece
--- /dev/null
+++ b/minidol/lib/ports.c
@@ -0,0 +1,80 @@
+/* ports implementation */
+#include <string.h>
+
+#include "../shared.h"
+
+extern shm_t shm;
+#define DEBUG0(X) { shm.states[14] = (uint32_t)(X); }
+#define DEBUG1(X) { shm.states[15] = (uint32_t)(X); }
+
+void delay()
+{
+	for(volatile long a = 0; a < 25; a++)
+		for(volatile long b = 0; b < 2000000; b++)
+			;
+}
+
+int size_shm(void *hwbuf)
+{
+	hwbuf_t *b = (hwbuf_t*)hwbuf;
+	return(b->size);
+}
+
+int level_shm(void *hwbuf)
+{
+	hwbuf_t *b = (hwbuf_t*)hwbuf;
+
+	int level = (b->wp - b->rp) % b->size;
+	if(level < 0) level += b->size;
+
+	return(level);
+}
+
+int read_shm (void *hwbuf, void *buf, int len)
+{
+	hwbuf_t *b = (hwbuf_t*)hwbuf;
+
+	/* block if necessary */
+	while(level_shm(hwbuf) < len);
+
+	/* copy data */
+	if(b->rp + len > b->size) {
+		/* wrap-around -> split access */
+		uint32_t amount = b->size - b->rp;
+		memcpy(buf, &b->buf[b->rp], amount);
+		memcpy(buf + amount, &b->buf[0], len - amount);
+	} else {
+		memcpy(buf, &b->buf[b->rp], len);
+	}
+
+	/* update read pointer */
+	b->rp = (b->rp + len) % b->size;
+
+	return(len);
+}
+
+int write_shm(void *hwbuf, void *buf, int len)
+{
+	hwbuf_t *b = (hwbuf_t*)hwbuf;
+
+	/* block if necessary */
+	while(b->size - level_shm(hwbuf) < len);
+
+	/* copy data */
+	if(b->wp + len > b->size) {
+		/* wrap-around -> split access */
+		uint32_t amount = b->size - b->wp;
+		memcpy(&b->buf[b->wp], buf, amount);
+		memcpy(&b->buf[0], buf + amount, len - amount);
+	} else {
+		memcpy(&b->buf[b->wp], buf, len);
+	}
+
+	/* update write pointer */
+	b->wp = (b->wp + len) % b->size;
+
+DEBUG1(level_shm(hwbuf)); delay();
+
+	return(len);
+}
+