From efc91241d93abcb6d4eb8fec1924c4d0988cce4f Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Sun, 20 Oct 2024 23:09:24 +0200
Subject: [PATCH] avr: new uart_bitbang module works now.

---
 avr/devices/n14/n14_main.asm           |   3 +-
 avr/modules/com2/buffer.asm            |   3 +-
 avr/modules/com2/main.asm              | 384 +++++++------------------
 avr/modules/comproto/msg_device.asm    |   1 -
 avr/modules/comproto/msg_memstats.asm  |   4 +-
 avr/modules/comproto/msg_value.asm     |  11 +-
 avr/modules/uart_bitbang/bytelevel.asm |   4 +-
 avr/modules/uart_bitbang/main.asm      |  45 ++-
 8 files changed, 137 insertions(+), 318 deletions(-)

diff --git a/avr/devices/n14/n14_main.asm b/avr/devices/n14/n14_main.asm
index 3a751f2..57ce67f 100644
--- a/avr/devices/n14/n14_main.asm
+++ b/avr/devices/n14/n14_main.asm
@@ -82,7 +82,7 @@
 
         rjmp BOOTLOADER_ADDR ; Reset vector  ; use this for flashed system
 	reti ; EXT_INT0
-	rjmp com2IsrPcint0 ; PCI0
+	rjmp uartBitbangIsrPcint0 ; PCI0
 	reti ; OC1A
 	reti ; OVF1
 	reti ; OVF0
@@ -127,6 +127,7 @@ firmwareStart:   rjmp main
 #ifdef MODULES_COM
   .include "modules/com2/defs.asm"
   .include "modules/com2/main.asm"
+  .include "modules/com2/buffer.asm"
   .include "modules/uart_bitbang/defs.asm"
   .include "modules/uart_bitbang/main.asm"
   .include "modules/uart_bitbang/bytelevel.asm"
diff --git a/avr/modules/com2/buffer.asm b/avr/modules/com2/buffer.asm
index 2f93e33..876f624 100644
--- a/avr/modules/com2/buffer.asm
+++ b/avr/modules/com2/buffer.asm
@@ -37,6 +37,7 @@
 ; @param %1 pointer to byte containing max number of buffers ever used
 ; @param %2 pointer to byte containing number of buffers currently in use
 ; @param %3 pointer to byte containing the write pointer
+; @param %4 pointer to routine to calculate buffer pos (e.g. uartBitbang_BufferPosToX)
 ; @return CFLAG set if okay, clear otherwise
 ; @return X pos to allocated buffer
 ; @clobbers R16, R17, R21
@@ -62,7 +63,7 @@ l0:
   clr r17                   ; wraparound
 l1:
   sts @3, r17               ; store new writepos for next caller
-  rcall COM2_BufferPosToX   ; (R16, R17)
+  rcall @4                  ; *_BufferPosToX(R16, R17)
   out SREG, r21             ; restore global interrupt enable bit in SREG
   sec
   rjmp l_end
diff --git a/avr/modules/com2/main.asm b/avr/modules/com2/main.asm
index 1b32d31..da9e6d9 100644
--- a/avr/modules/com2/main.asm
+++ b/avr/modules/com2/main.asm
@@ -42,12 +42,9 @@ com2SendStatsEnd:
   com2StatsNotForMe:       .byte 2
   com2StatsIgnored:        .byte 2
   
-  com2RecvBuffersUsed:     .byte 1
-  com2MaxBuffersUsed:      .byte 1
-  com2RecvBuffersWritePos: .byte 1
-  com2RecvBuffersReadPos:  .byte 1
+  com2MaxSendBuffersUsed:  .byte 1
+  com2MaxRecvBuffersUsed:  .byte 1
 
-  com2RecvBuffers:         .byte COM2_BUFFER_SIZE*COM2_BUFFER_NUM
   com2SendBuffer:          .byte COM2_BUFFER_SIZE
 com2DataEnd:
 
@@ -63,12 +60,6 @@ COM2_BEGIN:
 
 
 
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-; Module interface
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-
-
 ; ---------------------------------------------------------------------------
 ; Com2_Init
 ;
@@ -89,47 +80,48 @@ Com2_Init:
   clr r16
   sts com2Address, r16
 
-  ; setup pins and interrupts
-  cbi COM_PORT_DATA, COM_PINNUM_DATA      ; disable internal pullup for DATA
-  cbi COM_DDR_DATA, COM_PINNUM_DATA       ; set DATA port as input
-
-  cbi COM_PORT_ATTN, COM_PINNUM_ATTN      ; disable internal pullup for ATTN
-  cbi COM_DDR_ATTN, COM_PINNUM_ATTN       ; set ATTN port as input
-
-  sbi COM_IRQ_ADDR_ATTN, COM_IRQ_BIT_ATTN ; enable pin change irq for ATTN line
-  in r16, GIMSK                           ; enable pin change irq PCIE0 or PCIE1
-  ori r16, (1<<COM_IRQ_GIMSK_ATTN)
-  out GIMSK, R16
-  
-  ldi r16, (1<<COM_IRQ_GIFR_ATTN)         ; clear pending irq by writing 1 to ATTN bit
-  out GIFR, r16
-  
-  sec
-  ret
+  rjmp COMIO_Init
 
 
 
 ; ---------------------------------------------------------------------------
-; Com_Run
+; @routine Com2_Run @global
 ;
-; IN:
-; - nothing
-; OUT:
-; - CFLAG: set if something done, can be called again immediately (otherwise: wait for timer interrupt and retry)
-; REGS: (R1, R3, R16, R17, R18, R19, R22, X)
+; @return CFLAG set if something done, can be called again immediately (otherwise: wait for timer interrupt and retry)
+; @clobbers (R1, R3, R16, R17, R18, R19, R22, X)
 
 COM2_Run:
-  rjmp com2HandleNextPacketInQueue
+  rcall COMIO_Run
+  brcs COM2_Run_carrySet
+  rjmp com2HandleNextPacketInQueue  ; return CFLAG from com2HandleNextPacketInQueue
+COM2_Run_carrySet:
+  rcall com2HandleNextPacketInQueue
+  sec                               ; return CFLAG set regardless of com2HandleNextPacketInQueue
+  ret
+; @end
 
 
 
+; ---------------------------------------------------------------------------
+; @routine com2HandleNextPacketInQueue
+;
+; Get next received packet, call onPacketReceived on it and release it
+; @return CFLAG set if something done
+; @clobbers any
+
 com2HandleNextPacketInQueue:
-  lds r16, com2RecvBuffersUsed
-  tst r16
-  breq com2HandleNextPacketInQueue_retNc              ; no buffers in use
-  
-  lds r16, com2RecvBuffersReadPos
-  rcall COM2_BufferPosToX                             ; get current read buffer to X (R16, R17)
+  rcall COMIO_GetNextReceivedPacket
+  brcc com2HandleNextPacketInQueue_retNc
+  push xl
+    push xh
+      rcall com2CheckMessageInBuffer
+    pop xh
+  pop xl
+  brcs com2HandleNextPacketInQueue_crcOk
+  ldi xl, LOW(com2StatsContentError)
+  ldi xh, HIGH(com2StatsContentError)
+  rjmp com2HandleNextPacketInQueue_incCounterDeallocBuffer
+com2HandleNextPacketInQueue_crcOk:
   rcall onPacketReceived
   brcs com2HandleNextPacketInQueue_handled
   ldi xl, LOW(com2StatsIgnored)
@@ -140,13 +132,13 @@ com2HandleNextPacketInQueue_handled:
   ldi xh, HIGH(com2StatsHandled)
 com2HandleNextPacketInQueue_incCounterDeallocBuffer:
   rcall Utils_IncrementCounter16                      ; (r18, r19, r22)
-  rcall COM2_BufferDeallocFront                       ; (r16, r17, r21)
-  sec                                                 ; always return with set CFLAG
+  rcall COMIO_ReleaseReceivedPacket
+  sec
   ret
 com2HandleNextPacketInQueue_retNc:
   clc
   ret
-
+; @end
 
 
 
@@ -173,7 +165,7 @@ COM2_WriteMsgWithCmdAndSrcAddr:
   ldi r17, COM2_PAYLOAD_FLAGS_SECONDS
   push xh
     push xl
-      rcall COM2_BeginMsgWithVariablePayload     ; (R3, R4, R16, R17, R18, R19, R20, R21, X)
+      rcall COM2_BeginMsgWithVariablePayload    ; (R3, R4, R16, R17, R18, R19, R20, R21, X)
     pop xl
   pop xh
   rcall com2CalcAndAddChecksumByte              ; (R16, R17, R18, R19, X)
@@ -189,13 +181,12 @@ COM2_WriteMsgWithCmdAndSrcAddr_error:
 ; begin packet with variable payload.
 ;
 ; IN:
-; - R16: destination address
-; - R17: flags
-; - R18: command (e.g. CPRO_CMD_PING)
-; - X  : pointer to packet buffer
-; OUT:
-; - X  : points to end of packet as it was written so far
-; MODIFIED REGS: R3, R16, R17, R18, R19, R20, R21, X (R4)
+; @param R16 destination address
+; @param R17 flags
+; @param R18 command (e.g. CPRO_CMD_PING)
+; @param X   pointer to packet buffer
+; @return X  points to end of packet as it was written so far
+; @clobbers R3, R16, R17, R18, R19, R20, R21, X (R4)
 
 COM2_BeginMsgWithVariablePayload:
   ; write header (dest address, msg length)
@@ -213,14 +204,7 @@ COM2_BeginMsgWithVariablePayload:
   lsr r3                                   ; shift out COM2_PAYLOAD_FLAGS_SECONDS
   brcc COM2_BeginMsgWithVariablePayload_l1
   ; write seconds
-  lds r16, timerModuleCounterSecs          ; adding of current seconds counter requested
-  st X+, r16
-  lds r16, timerModuleCounterSecs+1
-  st X+, r16
-  lds r16, timerModuleCounterSecs+2
-  st X+, r16
-  lds r16, timerModuleCounterSecs+3
-  st X+, r16
+  rcall COM2_AddSecsToBuffer
 COM2_BeginMsgWithVariablePayload_l1:
   lsr r3                                   ; shift out COM2_PAYLOAD_FLAGS_UID
   brcc COM2_BeginMsgWithVariablePayload_l2
@@ -237,9 +221,6 @@ COM2_BeginMsgWithVariablePayload_l2:
 ; Write UID into buffer given by X.
 ;
 ; @return X   points to behind written uid
-; @param  R16 destination address
-; @param  R17 flags
-; @param  R18 command (e.g. CPRO_CMD_PING)
 ; @param  X   pointer to packet buffer
 ; @clobbers: r18, r19, r20, r21 (r16)
 
@@ -258,6 +239,54 @@ COM2_AddUidToBuffer:
 
 
 
+; ---------------------------------------------------------------------------
+; @routine COM2_AddSecsToBuffer @global
+;
+; Write current seconds counter (4 bytes) into buffer given by X, advance X.
+;
+; @return X   points to behind written seconds
+; @param  X   pointer to packet buffer
+; @clobbers: r16
+
+COM2_AddSecsToBuffer:
+  lds r16, timerModuleCounterSecs          ; add current seconds counter
+  st X+, r16
+  lds r16, timerModuleCounterSecs+1
+  st X+, r16
+  lds r16, timerModuleCounterSecs+2
+  st X+, r16
+  lds r16, timerModuleCounterSecs+3
+  st X+, r16
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine COM2_AddNextMsgIdToBuffer @global
+;
+; Write next message id (2 bytes) into buffer given by X, advance X.
+;
+; @return X   points to behind written message id
+; @param  X   pointer to packet buffer
+; @clobbers: r16, r17, r18
+
+COM2_AddNextMsgIdToBuffer:
+  ldi r18, 1
+  lds r16, com2LastMsgId
+  lds r17, com2LastMsgId+1
+  add r16, r18
+  dec r18
+  adc r17, r18
+  sts com2LastMsgId, r16
+  sts com2LastMsgId+1, r17
+  st X+, r16
+  st X+, r17
+  ret
+; @end
+
+
+
 ; ---------------------------------------------------------------------------
 ; com2CalcPayloadSize
 ;
@@ -290,243 +319,22 @@ com2CalcPayloadSize_l2:
 
 
 
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-; Sending and receiving messages
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-
-; ---------------------------------------------------------------------------
-; receive packet.
-;
-; OUT:
-; - CFLAG: set if okay (packet received), cleared on error
-; REGS: r16, r17, x (r18, r19, r20, r21, r22)
-
-com2ReceivePacket:
-  rcall COM2_BufferAlloc                 ; (r16, r17, r21)
-  brcs com2ReceivePacket_bufferAvailable
-  
-  ldi xl, LOW(com2StatsNoBufferError)    ; buffer in use, don't release
-  ldi xh, HIGH(com2StatsNoBufferError)   ; just increment error counter
-  rcall Utils_IncrementCounter16         ; (r18, r19, 22)
-  clc
-  ret
-com2ReceivePacket_bufferAvailable:
-  push xl
-    push xh
-      lds r16, com2Address
-      ldi r17, (COM2_BUFFER_SIZE-3)      ; buffer size minus dst addr, payload len, crc byte
-      rcall com2ReceivePacketRaw
-    pop xh
-  pop xl
-  brcc com2ReceivePacket_error
-
-  rcall com2CheckMessageInBuffer         ; (R16, R17, R18, R19, R20, X)
-  brcc com2ReceivePacket_dataError
-
-  ; everything okay
-  ldi xl, LOW(com2StatsPacketsIn)
-  ldi xh, HIGH(com2StatsPacketsIn)
-  rcall Utils_IncrementCounter16         ; (r18, r19, 22)
-  sec
-  ret
-
-com2ReceivePacket_error:
-  cpi r16, COM2_ERROR_IOERROR
-  breq com2ReceivePacket_ioError
-  cpi r16, COM2_ERROR_DATAERROR
-  breq com2ReceivePacket_dataError
-  cpi r16, COM2_ERROR_NOTFORME
-  breq com2ReceivePacket_notForMe
-  rjmp com2ReceivePacket_retnc
-com2ReceivePacket_ioError:
-  ldi xl, LOW(com2StatsIoError)
-  ldi xh, HIGH(com2StatsIoError)
-  rjmp com2ReceivePacket_incCounterDeallocNc
-com2ReceivePacket_dataError:
-  ldi xl, LOW(com2StatsContentError)
-  ldi xh, HIGH(com2StatsContentError)
-  rjmp com2ReceivePacket_incCounterDeallocNc
-com2ReceivePacket_notForMe:
-  ldi xl, LOW(com2StatsNotForMe)
-  ldi xh, HIGH(com2StatsNotForMe)
-  rjmp com2ReceivePacket_incCounterDeallocNc
-com2ReceivePacket_incCounterDeallocNc:
-  rcall Utils_IncrementCounter16         ; (r18, r19, 22)
-com2ReceivePacket_deallocRetnc:
-  rcall COM2_BufferDeallocBack
-com2ReceivePacket_retnc:
-  clc
-  ret
-
-
-
 ; ---------------------------------------------------------------------------
+; @routine COM2_SendPacket
 ; send packet from sendBuffer, if line free.
 ;
-; IN:
-; - nothing
-; OUT:
-; - CFLAG: set if okay (packet sent), cleared on error
-; REGS: r22, x (r18, r19, r22)
+; @return CFLAG set if okay (packet sent), cleared on error
+; @clobbers any (depending on io implementation)
 
 COM2_SendPacket:
   ldi xl, LOW(com2SendBuffer)
   ldi xh, HIGH(com2SendBuffer)
-
-COM2_SendPacketAtX:
-  rcall COM2_SendPacketWithAttn
-  brcs COM2_SendPacket_okay
-  
-  cpi r16, COM2_ERROR_BUSY
-  breq COM2_SendPacket_busyError
-  cpi r16, COM2_ERROR_COLLISION
-  breq COM2_SendPacket_collError
-
-COM2_SendPacket_busyError:
-  ldi xl, LOW(com2StatsBusyError)
-  ldi xh, HIGH(com2StatsBusyError)
-  rjmp COM2_SendPacket_incCounterRetNc
-COM2_SendPacket_collError:
-  ldi xl, LOW(com2StatsCollisions)
-  ldi xh, HIGH(com2StatsCollisions)
-COM2_SendPacket_incCounterRetNc:
-  rcall Utils_IncrementCounter16                 ; (r18, r19, r22)
-  clc
-  ret
-COM2_SendPacket_okay:
-  ldi xl, LOW(com2StatsPacketsOut)
-  ldi xh, HIGH(com2StatsPacketsOut)
-  rcall Utils_IncrementCounter16                 ; (r18, r19, r22)
-  sec
-  ret
+  rjmp COMIO_SendPacket
 
 
 
 
 
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-; Buffer Management
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-; ---------------------------------------------------------------------------
-; @routine COM2_BufferAlloc
-;
-; Allocate a transfer buffer.
-;
-; @return CFLAG set if okay, clear otherwise
-; @return X     pointer to allocated buffer in SRAM
-; @clobbers r16, r17, r21
-
-COM2_BufferAlloc:
-  COM2_M_BufferAlloc COM2_BUFFER_NUM, com2MaxBuffersUsed, com2RecvBuffersUsed, com2RecvBuffersWritePos
-  ret
-; @end
-
-
-
-; ---------------------------------------------------------------------------
-; @routine COM2_BufferDeallocBack
-;
-; Release a transfer buffer at the end of the list by decreasing the write pos.
-; This releases the last allocated buffer!
-;
-; @return CFLAG set if okay, clear otherwise
-; @clobbers r16, r17, r21
-
-COM2_BufferDeallocBack:
-  COM2_M_BufferDeallocBack COM2_BUFFER_NUM, com2RecvBuffersUsed, com2RecvBuffersWritePos
-  ret
-; @end
-
-
-
-; ---------------------------------------------------------------------------
-; @routine COM2_BufferDeallocFront
-;
-; Release a transfer buffer by increasing the read pos.
-;
-; @return CFLAG set if okay, clear otherwise
-; @clobbers r16, r17, r21
-
-COM2_BufferDeallocFront:
-  COM2_M_BufferDeallocFront COM2_BUFFER_NUM, com2RecvBuffersUsed, com2RecvBuffersReadPos
-  ret
-; @end
-
-
-
-; ---------------------------------------------------------------------------
-; @routine COM2_BufferPosToX
-;
-; Get a pointer to the SRAM position of the given buffer.
-; CAVE: Code must correspond to COM2_BUFFER_SIZE!!
-;
-; @param  R16 buffer number (starting with 0)
-; @return X   pointer to buffer in SRAM
-; @clobbers R16, R17
-
-COM2_BufferPosToX:
-  COM2_M_BufferPosToX com2RecvBuffers
-  ret
-; @end
-
-
-
-
-
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-; ISR
-; +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-
-
-com2IsrPcint0:
-  push r15
-    in r15, SREG
-    sbic COM_PIN_ATTN, COM_PINNUM_ATTN
-      rjmp com2IsrPcint0_end
-    ; low, read packet
-    push r1
-      push r16
-        push r17
-          push r18
-            push r19
-              push r20
-                push r21
-                  push r22
-                    push xh
-                     push xl
-                       push r15
-                         rcall com2ReceivePacket ; (r16, r17, r18, r19, r20, r21, r22, x)
-                       pop r15
-                       lds xl, com2Interrupts
-                       lds xh, com2Interrupts+1
-                       adiw xh:xl, 1
-                       sts com2Interrupts, xl
-                       sts com2Interrupts+1, xh
-                     pop xl
-                    pop xh
-                  pop r22
-                pop r21
-              pop r20
-            pop r19
-          pop r18
-        pop r17
-      pop r16
-    pop r1
-com2IsrPcint0_end:
-    out SREG, r15
-  pop r15
-  reti
-
-
-
-
-
-
-.include "modules/com2/packets.asm"
-.include "modules/com2/lowlevel.asm"
 .include "modules/com2/crc.asm"
 
 
diff --git a/avr/modules/comproto/msg_device.asm b/avr/modules/comproto/msg_device.asm
index 5f01bbd..0538616 100644
--- a/avr/modules/comproto/msg_device.asm
+++ b/avr/modules/comproto/msg_device.asm
@@ -44,4 +44,3 @@ CPRO_WriteDevice:
   ret
 
 
-
diff --git a/avr/modules/comproto/msg_memstats.asm b/avr/modules/comproto/msg_memstats.asm
index b9e364f..ee02093 100644
--- a/avr/modules/comproto/msg_memstats.asm
+++ b/avr/modules/comproto/msg_memstats.asm
@@ -40,9 +40,9 @@ CPRO_WriteMemStats:
       in r17, SPH
       sbc r21, r17
       st X+, r21
-      lds r17, com2RecvBuffersUsed            
+      lds r17, com2MaxSendBuffersUsed            
       st X+, r17                             ; used buffers
-      lds r17, com2MaxBuffersUsed
+      lds r17, com2MaxRecvBuffersUsed
       st X+, r17                             ; max used buffers
       lds r17, com2StatsNoBufferError          
       st X+, r17                             ; recvNoBuffer
diff --git a/avr/modules/comproto/msg_value.asm b/avr/modules/comproto/msg_value.asm
index 1aa6022..211452f 100644
--- a/avr/modules/comproto/msg_value.asm
+++ b/avr/modules/comproto/msg_value.asm
@@ -34,16 +34,7 @@ CPRO_WriteReportValue:
 
   ; set msg id
   adiw xh:xl, CPRO_PACKET_VALUE_OFFS_MSGID
-  ldi r18, 1
-  lds r16, com2LastMsgId
-  lds r17, com2LastMsgId+1
-  add r16, r18
-  dec r18
-  adc r17, r18
-  sts com2LastMsgId, r16
-  sts com2LastMsgId+1, r17
-  st X+, r16
-  st X+, r17
+  rcall COM2_AddNextMsgIdToBuffer            ; (r16, r17, r18)
   sbiw xh:xl, CPRO_PACKET_VALUE_OFFS_MSGID+2 ; go back to begin  of msg
   
   ; calc and add checksum
diff --git a/avr/modules/uart_bitbang/bytelevel.asm b/avr/modules/uart_bitbang/bytelevel.asm
index caf5ffa..6c52da1 100644
--- a/avr/modules/uart_bitbang/bytelevel.asm
+++ b/avr/modules/uart_bitbang/bytelevel.asm
@@ -157,7 +157,7 @@ uartBitbang_ReceiveByte_error:
 ; ---------------------------------------------------------------------------
 ; @routine uartBitbang_WaitForDataLow
 ;
-; Wait for data pin to become low
+; Wait up to 1ms for data pin to become low
 ; @return CFLAG set if okay, clear otherwise
 ; @clobbers R17, R22
 
@@ -171,7 +171,7 @@ uartBitbang_WaitForDataLow:
 ; ---------------------------------------------------------------------------
 ; @routine uartBitbang_WaitForDataHigh
 ;
-; Wait for data pin to become high
+; Wait up to 1ms for data pin to become high
 ; @return CFLAG set if okay, clear otherwise
 ; @clobbers R17, R22
 
diff --git a/avr/modules/uart_bitbang/main.asm b/avr/modules/uart_bitbang/main.asm
index f2fdd6d..48b01a3 100644
--- a/avr/modules/uart_bitbang/main.asm
+++ b/avr/modules/uart_bitbang/main.asm
@@ -12,12 +12,11 @@
 ; UART_BitBang_Init
 ; UART_BitBang_Fini
 ; UART_BitBang_Run
-; UART_BitBang_SendPacket:
-; UART_BitBang_GetNextReceivedPacket:
-; UART_BitBang_ReleaseReceivedPacket:
+; UART_BitBang_SendPacket
+; UART_BitBang_GetNextReceivedPacket
+; UART_BitBang_ReleaseReceivedPacket
 
 
-.include "modules/com2/buffer.asm"
 
 
 
@@ -29,7 +28,6 @@
 
 uartBitbangDataBegin:
   uartBitbangRecvBuffersUsed:     .byte 1
-  uartBitbangMaxBuffersUsed:      .byte 1
   uartBitbangRecvBuffersWritePos: .byte 1
   uartBitbangRecvBuffersReadPos:  .byte 1
   uartBitbangRecvBuffers:         .byte COM2_BUFFER_SIZE*UART_BITBANG_BUFFER_NUM
@@ -85,7 +83,7 @@ UART_BitBang_Init:
 
 
 ; ---------------------------------------------------------------------------
-; @routine UART_BitBang_Init
+; @routine UART_BitBang_Fini
 ;
 ; @return CFLAG set if okay, clear on error
 ; @clobbers R16, R17, X, Y
@@ -113,6 +111,7 @@ UART_BitBang_Fini:
 ; @clobbers any
 
 UART_BitBang_Run:
+  clc
   ret
 ; @end
 
@@ -127,6 +126,22 @@ UART_BitBang_Run:
 ; @clobbers r22, x (r18, r19, r22)
 
 UART_BitBang_SendPacket:
+  push r15
+    in r15, SREG
+    cli
+    rcall UART_BitBang_SendPacket_noIrqs
+    brcc UART_BitBang_SendPacket_retErr
+    out SREG, r15
+  pop r15
+  sec
+  ret
+UART_BitBang_SendPacket_retErr:
+    out SREG, r15
+  pop r15
+  clc
+  ret
+
+UART_BitBang_SendPacket_noIrqs:
   rcall uartBitbang_SendPacket
   brcs UART_BitBang_SendPacket_okay
   cpi r16, COM2_ERROR_BUSY
@@ -189,8 +204,8 @@ UART_BitBang_GetNextReceivedPacket_retNc:
 ; @clobbers r16, r17, r21
 
 UART_BitBang_ReleaseReceivedPacket:
-  rjmp COM2_BufferDeallocFront                       ; (r16, r17, r21)
-
+  rjmp uartBitbang_BufferDeallocFront  ; (r16, r17, r21)
+; @end
 
 
 
@@ -285,7 +300,11 @@ uartBitbang_ReceivePacket_retnc:
 ; @clobbers r16, r17, r21
 
 uartBitbang_BufferAlloc:
-  COM2_M_BufferAlloc UART_BITBANG_BUFFER_NUM, uartBitbangMaxBuffersUsed, uartBitbangRecvBuffersUsed, uartBitbangRecvBuffersWritePos
+  COM2_M_BufferAlloc UART_BITBANG_BUFFER_NUM, \
+    com2MaxRecvBuffersUsed, \
+    uartBitbangRecvBuffersUsed, \
+    uartBitbangRecvBuffersWritePos, \
+    uartBitbang_BufferPosToX
   ret
 ; @end
 
@@ -394,10 +413,10 @@ uartBitbangIsrPcint0_end:
 
 
 ; set routine functions
-.equ COMIO_Init = UART_BitBang_Init
-.equ COMIO_Fini = UART_BitBang_Fini
-.equ COMIO_Run = UART_BitBang_Run
-.equ COMIO_SendPacket = UART_BitBang_SendPacket
+.equ COMIO_Init                  = UART_BitBang_Init
+.equ COMIO_Fini                  = UART_BitBang_Fini
+.equ COMIO_Run                   = UART_BitBang_Run
+.equ COMIO_SendPacket            = UART_BitBang_SendPacket
 .equ COMIO_GetNextReceivedPacket = UART_BitBang_GetNextReceivedPacket
 .equ COMIO_ReleaseReceivedPacket = UART_BitBang_ReleaseReceivedPacket