Simple IPC with pipes

kernel/rbuf/rbuf.c

@@ -0,0 +1,37 @@
+#include <stdint.h>
+#include <stddef.h>
+#include "rbuf.h"
+
+int32_t rbuf_push(RBuf *rbuf, uint8_t data) {
+  size_t next;
+
+  next = rbuf->head + 1;
+  if (next >= rbuf->cap) {
+    next = 0;
+  }
+
+  if (next == rbuf->tail) {
+    return -1;
+  }
+
+  rbuf->buffer[rbuf->head] = data;
+  rbuf->head = next;
+  return 0;
+}
+
+int32_t rbuf_pop(RBuf *rbuf, uint8_t *data) {
+  size_t next;
+
+  if (rbuf->head == rbuf->tail) {
+    return -1;
+  }
+
+  next = rbuf->tail + 1;
+  if (next >= rbuf->cap) {
+    next = 0;
+  }
+
+  *data = rbuf->buffer[rbuf->tail];
+  rbuf->tail = next;
+  return 0;
+}

kernel/rbuf/rbuf.h

@@ -0,0 +1,17 @@
+#ifndef RBUF_RBUF_H_
+#define RBUF_RBUF_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+typedef struct {
+  uint8_t *buffer;
+  size_t head;
+  size_t tail;
+  size_t cap;
+} RBuf;
+
+int32_t rbuf_push(RBuf *rbuf, uint8_t data);
+int32_t rbuf_pop(RBuf *rbuf, uint8_t *data);
+
+#endif // RBUF_RBUF_H_