through SendRecvDone

asm/link.s

@@ -5,283 +5,6 @@
 
 	.text
 
-	thumb_func_start DoRecv
-DoRecv: @ 800BBCC
-	push {r4-r7,lr}
-	mov r7, r8
-	push {r7}
-	sub sp, 0x8
-	ldr r0, =0x04000120
-	ldr r1, [r0, 0x4]
-	ldr r0, [r0]
-	str r0, [sp]
-	str r1, [sp, 0x4]
-	ldr r0, =gLink
-	ldrb r1, [r0, 0x16]
-	adds r6, r0, 0
-	cmp r1, 0
-	bne _0800BC30
-	movs r4, 0
-	ldr r7, =gUnknown_03000D72
-	ldrb r0, [r6, 0x3]
-	cmp r4, r0
-	bcs _0800BC1A
-	adds r5, r6, 0
-	ldrh r1, [r6, 0x14]
-	adds r3, r7, 0
-	adds r2, r6, 0
-_0800BBFA:
-	lsls r0, r4, 1
-	add r0, sp
-	ldrh r0, [r0]
-	cmp r1, r0
-	beq _0800BC0E
-	ldrb r0, [r3]
-	cmp r0, 0
-	beq _0800BC0E
-	movs r0, 0x1
-	strb r0, [r5, 0x11]
-_0800BC0E:
-	adds r0, r4, 0x1
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldrb r0, [r2, 0x3]
-	cmp r4, r0
-	bcc _0800BBFA
-_0800BC1A:
-	movs r0, 0
-	strh r0, [r6, 0x14]
-	movs r0, 0x1
-	strb r0, [r7]
-	b _0800BCD0
-	.pool
-_0800BC30:
-	ldr r2, =0x00000fbc
-	adds r1, r6, r2
-	adds r2, 0x1
-	adds r0, r6, r2
-	ldrb r2, [r0]
-	ldrb r1, [r1]
-	adds r0, r2, r1
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x31
-	bls _0800BC4C
-	subs r0, 0x32
-	lsls r0, 24
-	lsrs r0, 24
-_0800BC4C:
-	cmp r2, 0x31
-	bhi _0800BCA8
-	movs r4, 0
-	ldrb r1, [r6, 0x3]
-	cmp r4, r1
-	bcs _0800BCAC
-	adds r5, r6, 0
-	ldr r7, =gUnknown_03000D70
-	lsls r0, 1
-	mov r12, r0
-	movs r2, 0xCF
-	lsls r2, 2
-	adds r2, r6
-	mov r8, r2
-_0800BC68:
-	lsls r1, r4, 1
-	mov r2, sp
-	adds r0, r2, r1
-	ldrh r3, [r0]
-	ldrh r2, [r5, 0x14]
-	adds r0, r3, r2
-	strh r0, [r5, 0x14]
-	ldrh r0, [r7]
-	orrs r0, r3
-	strh r0, [r7]
-	ldrb r2, [r5, 0x17]
-	movs r0, 0x64
-	muls r0, r2
-	add r0, r12
-	adds r1, r4
-	lsls r1, 3
-	adds r1, r4
-	lsls r1, 5
-	adds r0, r1
-	add r0, r8
-	strh r3, [r0]
-	adds r0, r4, 0x1
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldrb r0, [r5, 0x3]
-	cmp r4, r0
-	bcc _0800BC68
-	b _0800BCAC
-	.pool
-_0800BCA8:
-	movs r0, 0x2
-	strb r0, [r6, 0x12]
-_0800BCAC:
-	ldrb r0, [r6, 0x17]
-	adds r0, 0x1
-	strb r0, [r6, 0x17]
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x8
-	bne _0800BCD0
-	ldr r2, =gUnknown_03000D70
-	ldrh r0, [r2]
-	cmp r0, 0
-	beq _0800BCD0
-	ldr r1, =0x00000fbd
-	adds r0, r6, r1
-	ldrb r1, [r0]
-	adds r1, 0x1
-	strb r1, [r0]
-	movs r0, 0
-	strh r0, [r2]
-_0800BCD0:
-	add sp, 0x8
-	pop {r3}
-	mov r8, r3
-	pop {r4-r7}
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end DoRecv
-
-	thumb_func_start DoSend
-DoSend: @ 800BCE4
-	push {r4,lr}
-	ldr r0, =gLink
-	ldrb r1, [r0, 0x16]
-	adds r4, r0, 0
-	cmp r1, 0x8
-	bne _0800BD36
-	ldr r1, =0x0400012a
-	ldrh r0, [r4, 0x14]
-	strh r0, [r1]
-	ldr r1, =gUnknown_03000D6D
-	ldrb r2, [r1]
-	cmp r2, 0
-	bne _0800BD30
-	ldr r0, =0x00000339
-	adds r1, r4, r0
-	ldrb r0, [r1]
-	subs r0, 0x1
-	strb r0, [r1]
-	movs r0, 0xCE
-	lsls r0, 2
-	adds r1, r4, r0
-	ldrb r0, [r1]
-	adds r0, 0x1
-	strb r0, [r1]
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x31
-	bls _0800BD8C
-	strb r2, [r1]
-	b _0800BD8C
-	.pool
-_0800BD30:
-	movs r0, 0
-	strb r0, [r1]
-	b _0800BD8C
-_0800BD36:
-	ldr r1, =gUnknown_03000D6D
-	ldrb r0, [r1]
-	cmp r0, 0
-	bne _0800BD52
-	ldr r2, =0x00000339
-	adds r0, r4, r2
-	ldrb r0, [r0]
-	cmp r0, 0
-	bne _0800BD4C
-	movs r0, 0x1
-	strb r0, [r1]
-_0800BD4C:
-	ldrb r0, [r1]
-	cmp r0, 0
-	beq _0800BD68
-_0800BD52:
-	ldr r1, =0x0400012a
-	movs r0, 0
-	strh r0, [r1]
-	b _0800BD86
-	.pool
-_0800BD68:
-	ldr r3, =0x0400012a
-	movs r1, 0xCE
-	lsls r1, 2
-	adds r0, r4, r1
-	ldrb r0, [r0]
-	lsls r0, 1
-	ldrb r2, [r4, 0x16]
-	movs r1, 0x64
-	muls r1, r2
-	adds r0, r1
-	adds r1, r4, 0
-	adds r1, 0x18
-	adds r0, r1
-	ldrh r0, [r0]
-	strh r0, [r3]
-_0800BD86:
-	ldrb r0, [r4, 0x16]
-	adds r0, 0x1
-	strb r0, [r4, 0x16]
-_0800BD8C:
-	pop {r4}
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end DoSend
-
-	thumb_func_start StopTimer
-StopTimer: @ 800BD98
-	push {lr}
-	ldr r0, =gLink
-	ldrb r0, [r0]
-	cmp r0, 0
-	beq _0800BDB4
-	ldr r2, =0x0400010e
-	ldrh r1, [r2]
-	ldr r0, =0x0000ff7f
-	ands r0, r1
-	strh r0, [r2]
-	ldr r1, =0x0400010c
-	ldr r2, =0x0000ff3b
-	adds r0, r2, 0
-	strh r0, [r1]
-_0800BDB4:
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end StopTimer
-
-	thumb_func_start SendRecvDone
-SendRecvDone: @ 800BDCC
-	push {lr}
-	ldr r1, =gLink
-	ldrb r0, [r1, 0x17]
-	cmp r0, 0x8
-	bne _0800BDE4
-	movs r0, 0
-	strb r0, [r1, 0x16]
-	strb r0, [r1, 0x17]
-	b _0800BDF4
-	.pool
-_0800BDE4:
-	ldrb r0, [r1]
-	cmp r0, 0
-	beq _0800BDF4
-	ldr r0, =0x0400010e
-	ldrh r1, [r0]
-	movs r2, 0x80
-	orrs r1, r2
-	strh r1, [r0]
-_0800BDF4:
-	pop {r0}
-	bx r0
-	.pool
-	thumb_func_end SendRecvDone
-
 	thumb_func_start sub_800BDFC
 sub_800BDFC: @ 800BDFC
 	push {r4-r6,lr}

src/link.c

@@ -61,10 +61,10 @@ IWRAM_DATA u32 gUnknown_03000D60;
 IWRAM_DATA u8 sLinkTestLastBlockSendPos;
 ALIGNED() IWRAM_DATA u8 sLinkTestLastBlockRecvPos[MAX_LINK_PLAYERS];
 IWRAM_DATA u8 sNumVBlanksWithoutSerialIntr;
-IWRAM_DATA bool8 gUnknown_03000D6D;
+IWRAM_DATA bool8 sSendBufferEmpty;
 IWRAM_DATA u16 sSendNonzeroCheck;
-IWRAM_DATA u16 gUnknown_03000D70;
+IWRAM_DATA u16 sRecvNonzeroCheck;
-IWRAM_DATA u8 gUnknown_03000D72;
+IWRAM_DATA u8 sChecksumAvailable;
 IWRAM_DATA u8 sHandshakePlayerCount;
 IWRAM_DATA u8 gUnknown_03000D74;
 
@@ -161,10 +161,10 @@ static void EnqueueSendCmd(u16 *sendCmd);
 static void DequeueRecvCmds(u16 (*recvCmds)[CMD_LENGTH]);
 static void StartTransfer(void);
 static bool8 DoHandshake(void);
-void DoRecv(void);
+static void DoRecv(void);
-void DoSend(void);
+static void DoSend(void);
-void StopTimer(void);
+static void StopTimer(void);
-void SendRecvDone(void);
+static void SendRecvDone(void);
 
 // .rodata
 
@@ -1927,8 +1927,8 @@ static void EnableSerial(void)
     CpuFill32(0, &gLink, sizeof(gLink));
     sNumVBlanksWithoutSerialIntr = 0;
     sSendNonzeroCheck = 0;
-    gUnknown_03000D70 = 0;
+    sRecvNonzeroCheck = 0;
-    gUnknown_03000D72 = 0;
+    sChecksumAvailable = 0;
     sHandshakePlayerCount = 0;
     gLastSendQueueCount = 0;
     gLastRecvQueueCount = 0;
@@ -2061,7 +2061,7 @@ static void InitTimer(void)
 {
     if (gLink.isMaster)
     {
-        REG_TM3CNT_L = 0xFF3B;
+        REG_TM3CNT_L = -197;
         REG_TM3CNT_H = TIMER_64CLK | TIMER_INTR_ENABLE;
         EnableInterrupts(INTR_FLAG_TIMER3);
     }
@@ -2142,6 +2142,8 @@ static void DequeueRecvCmds(u16 (*recvCmds)[CMD_LENGTH])
     REG_IME = gLinkSavedIme;
 }
 
+// link_intr.c
+
 void LinkVSync(void)
 {
     if (gLink.isMaster)
@@ -2287,3 +2289,110 @@ static bool8 DoHandshake(void)
     sHandshakePlayerCount = gLink.playerCount;
     return FALSE;
 }
+
+static void DoRecv(void)
+{
+    u16 recv[4];
+    u8 i;
+    u8 index;
+
+    *(u64 *)recv = REG_SIOMLT_RECV;
+    if (gLink.sendCmdIndex == 0)
+    {
+        for (i = 0; i < gLink.playerCount; i++)
+        {
+            if (gLink.checksum != recv[i] && sChecksumAvailable)
+            {
+                gLink.badChecksum = TRUE;
+            }
+        }
+        gLink.checksum = 0;
+        sChecksumAvailable = TRUE;
+    }
+    else
+    {
+        index = gLink.recvQueue.pos + gLink.recvQueue.count;
+        if (index >= QUEUE_CAPACITY)
+        {
+            index -= QUEUE_CAPACITY;
+        }
+        if (gLink.recvQueue.count < QUEUE_CAPACITY)
+        {
+            for (i = 0; i < gLink.playerCount; i++)
+            {
+                gLink.checksum += recv[i];
+                sRecvNonzeroCheck |= recv[i];
+                gLink.recvQueue.data[i][gLink.recvCmdIndex][index] = recv[i];
+            }
+        }
+        else
+        {
+            gLink.queueFull = QUEUE_FULL_RECV;
+        }
+        gLink.recvCmdIndex++;
+        if (gLink.recvCmdIndex == CMD_LENGTH && sRecvNonzeroCheck)
+        {
+            gLink.recvQueue.count++;
+            sRecvNonzeroCheck = 0;
+        }
+    }
+}
+
+static void DoSend(void)
+{
+    if (gLink.sendCmdIndex == CMD_LENGTH)
+    {
+        REG_SIOMLT_SEND = gLink.checksum;
+        if (!sSendBufferEmpty)
+        {
+            gLink.sendQueue.count--;
+            gLink.sendQueue.pos++;
+            if (gLink.sendQueue.pos >= QUEUE_CAPACITY)
+            {
+                gLink.sendQueue.pos = 0;
+            }
+        }
+        else
+        {
+            sSendBufferEmpty = FALSE;
+        }
+    }
+    else
+    {
+        if (!sSendBufferEmpty && gLink.sendQueue.count == 0)
+        {
+            sSendBufferEmpty = TRUE;
+        }
+        if (sSendBufferEmpty)
+        {
+            REG_SIOMLT_SEND = 0;
+        }
+        else
+        {
+            REG_SIOMLT_SEND = gLink.sendQueue.data[gLink.sendCmdIndex][gLink.sendQueue.pos];
+        }
+        gLink.sendCmdIndex++;
+    }
+}
+
+static void StopTimer(void)
+{
+    if (gLink.isMaster)
+    {
+        REG_TM3CNT_H &= ~TIMER_ENABLE;
+        REG_TM3CNT_L = -197;
+    }
+}
+
+static void SendRecvDone(void)
+{
+    if (gLink.recvCmdIndex == CMD_LENGTH)
+    {
+        gLink.sendCmdIndex = 0;
+        gLink.recvCmdIndex = 0;
+    }
+    else if (gLink.isMaster)
+    {
+        REG_TM3CNT_H |= TIMER_ENABLE;
+    }
+}