feat: add MboxChannel enum and use it in mboxCall

kkebo · Aug 31, 2024 · 4aec962 · 4aec962
1 parent 7f49663
commit 4aec962
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Showing 2 changed files with 16 additions and 3 deletions.
diff --git a/Sources/Kernel/mbox.swift b/Sources/Kernel/mbox.swift
@@ -11,6 +11,19 @@ let mboxResponse: UInt32 = 0x8000_0000
 let mboxFull: UInt32 = 0x8000_0000
 let mboxEmpty: UInt32 = 0x4000_0000
 
+enum MboxChannel: UInt8 {
+    case power = 0
+    case framebuffer
+    case virtualUART
+    case vchiq
+    case leds
+    case buttons
+    case touchScreen
+    case count  // TODO: Understand what this is.
+    case property  // ARM -> VC
+    // case property  // VC -> ARM
+}
+
 enum MboxTag {
     static let end: UInt32 = 0
     static let setClockRate: UInt32 = 0x0003_8002
@@ -26,10 +39,10 @@ private func receiveMboxEmpty() -> Bool {
     mmioLoad(mboxStatus) & mboxEmpty > 0
 }
 
-func mboxCall(ch: UInt8) -> Bool {
+func mboxCall(ch: MboxChannel) -> Bool {
     withUnsafePointer(to: &mbox) { ptr in
         let addr = UInt32(UInt(bitPattern: ptr))
-        let r = addr & ~0xF | UInt32(ch & 0xF)
+        let r = addr & ~0xF | UInt32(ch.rawValue & 0xF)
         while transmitMboxFull() {}
         mmioStore(r, to: mboxWrite)
         repeat {

diff --git a/Sources/Kernel/uart.swift b/Sources/Kernel/uart.swift
@@ -64,7 +64,7 @@ func initUART() {
         mbox.6 = 3_000_000  // 3 Mhz
         mbox.7 = 0  // clear turbo
         mbox.8 = MboxTag.end
-        guard mboxCall(ch: 8) else { fatalError() }
+        guard mboxCall(ch: .property) else { fatalError() }
     #endif
 
     // map UART0 to GPIO pins