Rewrite ps2kbproc, rbuf (kernel ring buffer) and pipe read/write, Change to -O0 in kernel code

kernel/rbuf/rbuf.c

@@ -1,37 +1,34 @@
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 #include "rbuf.h"
+#include "kprintf.h"
+#include "hal/hal.h"
+
+void rbuf_init(RBuf *rbuf, uint8_t *buf, size_t bufsize) {
+  rbuf->buffer = buf;
+  rbuf->tail = 0;
+  rbuf->head = 0;
+  rbuf->cap = bufsize;
+  rbuf->count = 0;
+}
 
 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) {
+  if (rbuf->count == rbuf->cap) {
     return -1;
   }
-
   rbuf->buffer[rbuf->head] = data;
-  rbuf->head = next;
+  rbuf->head = (rbuf->head + 1) % rbuf->cap;
+  rbuf->count++;
   return 0;
 }
 
 int32_t rbuf_pop(RBuf *rbuf, uint8_t *data) {
-  size_t next;
-
-  if (rbuf->head == rbuf->tail) {
+  if (rbuf->count == 0) {
     return -1;
   }
-
-  next = rbuf->tail + 1;
-  if (next >= rbuf->cap) {
-    next = 0;
-  }
-
   *data = rbuf->buffer[rbuf->tail];
-  rbuf->tail = next;
+  rbuf->tail = (rbuf->tail + 1) % rbuf->cap;
+  rbuf->count--;
   return 0;
 }

kernel/rbuf/rbuf.h

@@ -3,15 +3,19 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 
 typedef struct {
   uint8_t *buffer;
-  size_t head;
   size_t tail;
+  size_t head;
   size_t cap;
+  size_t count;
+  bool full;
 } RBuf;
 
 int32_t rbuf_push(RBuf *rbuf, uint8_t data);
 int32_t rbuf_pop(RBuf *rbuf, uint8_t *data);
+void rbuf_init(RBuf *rbuf, uint8_t *buf, size_t bufsize);
 
 #endif // RBUF_RBUF_H_