avr: more work on hardware based uart module.

avr/modules/uart_hw/lowlevel.asm

@@ -27,7 +27,7 @@ UART_HW_Init:
   rcall Utils_FillSram
 
   rcall UART_HW_FixedBuffers_Init
-  
+
   ldi r16, UART_HW_MSGNUMINBUF_SIZE
   ldi yl, LOW(uartHw_ringBufferMsgNumIn)
   ldi yh, HIGH(uartHw_ringBufferMsgNumIn)
@@ -37,7 +37,8 @@ UART_HW_Init:
   ldi yl, LOW(uartHw_ringBufferMsgNumOut)
   ldi yh, HIGH(uartHw_ringBufferMsgNumOut)
   rcall RingBufferY_Init
-  
+
+
   sec
   ret
 ; @end
@@ -67,6 +68,9 @@ UART_HW_InterfaceInit:
                        UART_HW_IFACE_OFFS_WRITEBUF_RDPOS, \
                        UART_HW_IFACE_OFFS_WRITEBUF_WRPOS, \
                        UART_HW_IFACE_OFFS_WRITEBUF_DATA
+  ldi r16, 0xff
+  std Y+UART_HW_IFACE_OFFS_READMSG_BUFNUM, r16
+  std Y+UART_HW_IFACE_OFFS_WRITEMSG_BUFNUM, r16
   ret
 ; @end
 
@@ -84,7 +88,7 @@ UART_HW_InterfaceWriteToReadBuffer:
   push yl
     push yh
       adiw yh:yl, UART_HW_IFACE_OFFS_READBUF
-      rcall RingBufferY_WriteByte                  ; R17, R18, X
+      rcall uartHwRingBufferWriteGuarded           ; R17, R18, X
     pop yh
   pop yl
   ret
@@ -104,7 +108,7 @@ UART_HW_InterfaceReadFromReadBuffer:
   push yl
     push yh
       adiw yh:yl, UART_HW_IFACE_OFFS_READBUF
-      rcall RingBufferY_ReadByte                  ; R17, R18, X
+      rcall uartHwRingBufferReadGuarded           ; R17, R18, X
     pop yh
   pop yl
   ret
@@ -124,7 +128,7 @@ UART_HW_InterfaceWriteToWriteBuffer:
   push yl
     push yh
       adiw yh:yl, UART_HW_IFACE_OFFS_WRITEBUF
-      rcall RingBufferY_WriteByte                  ; R17, R18, X
+      rcall uartHwRingBufferWriteGuarded           ; R17, R18, X
     pop yh
   pop yl
   ret
@@ -144,7 +148,7 @@ UART_HW_InterfaceReadFromWriteBuffer:
   push yl
     push yh
       adiw yh:yl, UART_HW_IFACE_OFFS_WRITEBUF
-      rcall RingBufferY_ReadByte                  ; R17, R18, X
+      rcall uartHwRingBufferReadGuarded           ; R17, R18, X
     pop yh
   pop yl
   ret
@@ -152,6 +156,67 @@ UART_HW_InterfaceReadFromWriteBuffer:
 
 
 
+UART_HW_Interface_Run:
+
+
+
+
+; ---------------------------------------------------------------------------
+; @routine uartHwRingBufferReadGuarded
+;
+; @return CFLAG on success, cleared on error
+; @param r16 byte to write
+; @param Y pointer to start of interface data
+; @clobbers R17, R18, X
+
+uartHwRingBufferReadGuarded:
+  push r15
+    in r15, SREG
+    cli
+    rcall RingBufferY_ReadByte                  ; R17, R18, X
+    brcc uartHwRingBufferReadGuarded_error
+    out SREG, r15
+  pop r15
+  sec
+  ret
+uartHwRingBufferReadGuarded_error:
+    out SREG, r15
+  pop r15
+  clc
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine uartHwRingBufferWriteGuarded
+;
+; @return CFLAG on success, cleared on error
+; @param r16 byte to write
+; @param Y pointer to start of interface data
+; @clobbers R17, R18, X
+
+uartHwRingBufferWriteGuarded:
+  push r15
+    in r15, SREG
+    cli
+    rcall RingBufferY_WriteByte                  ; R17, R18, X
+    brcc uartHwRingBufferWriteGuarded_error
+    out SREG, r15
+  pop r15
+  sec
+  ret
+uartHwRingBufferWriteGuarded_error:
+    out SREG, r15
+  pop r15
+  clc
+  ret
+; @end
+
+
+
+
+