1 files changed, 28 insertions, 3 deletions

diff --git a/src/mailbox.h b/src/mailbox.h
index e96a4ed..3cca366 100644
--- a/src/mailbox.h
+++ b/src/mailbox.h
@@ -11,6 +11,29 @@ enum
   PROPERTY_CHANNEL = 8,
 };
 
+enum
+{
+  MAILBOX_REQUEST  = 0,
+  MAILBOX_RESPONSE = 1,
+};
+
+enum
+{
+  MAILBOX_DELIVERY_ERROR = 0,
+  MAILBOX_ERROR          = 0x80000001,
+  MAILBOX_SUCCESS        = 0x80000000,
+};
+
+enum
+{
+  TAG_END                                  = 0,
+  TAG_FRAMEBUFFER_ALLOCATE                 = 0x00040001,
+  TAG_FRAMEBUFFER_RELEASE                  = 0x00048001,
+  TAG_FRAMEBUFFER_SET_PHYSICAL_SCREEN_SIZE = 0x00048003,
+  TAG_FRAMEBUFFER_SET_VIRTUAL_SCREEN_SIZE  = 0x00048004,
+  TAG_FRAMEBUFFER_SET_DEPTH                = 0x00048005,
+};
+
 typedef struct Tag {
   union {
     uint32_t all;
@@ -23,16 +46,18 @@ typedef struct Tag {
   };
   uint32_t size;    // Buffer size.
   uint32_t code;    // Request/response code.
-  uint32_t data[1]; // Buffer data.
+  uint32_t data[];  // Buffer data.
 } Tag;
 
 typedef struct __attribute__((aligned(MAIL_ALIGN))) Mail {
   uint32_t size;    // Buffer size.
   uint32_t code;    // Request/response code.
-  Tag      tags[1]; // Variable quantity.
+  Tag      tags[];  // Variable quantity.
 } Mail;
 
+#define MAIL_SIZE(TYPE) (sizeof(TYPE) + (2 * sizeof(uint32_t)))
+
 void        mbox_init();
 const Mail* mbox_read(uint8_t channel);
-void        mbox_write(uint8_t channel, const void* mail);
+void        mbox_write(uint8_t channel, volatile const void* mail);