Leahnaya/Poke_Transporter_GB
1
0
Fork 0
mirror of https://github.com/GearsProgress/Poke_Transporter_GB.git synced 2026-09-09 01:25:35 -05:00
Code Issues Actions Packages Projects Releases Wiki Activity

Improving the link cable connection initialization

Browse Source
This commit is contained in:
GearsProgress
2026-08-29 13:23:33 -04:00
parent 1afb528c73
commit 608022a80e
2 changed files with 90 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
source/link_handler.cpp
View File

@@ -40,6 +40,12 @@
LinkSPI linkSPIInstance;
LinkSPI *linkSPI = &linkSPIInstance;
#define INITIAL_LINK_TIMER (0x4000 / 60)
#define DISCOVERY_TIMER_MIN 4
#define DISCOVERY_TIMER_PHASE_MASK 0x0F
#define DISCOVERY_TIMEOUT_TRANSFERS 2048
#define DISCOVERY_CONFIRM_TIMEOUT_TRANSFERS 180
// Here's a compilation check to ensure that the size of these structs match our expectations.
// Just update it if you changed the struct members. The data-generator process prints their actual sizes.
static_assert(sizeof(struct GB_ROM) == 140);
@@ -287,7 +293,22 @@ void LinkConnection::startConnection(LinkState startState)
switch (startState)
{
case INITIAL_CONNECTION:
REG_TM3D = -0x4000 / 60;
// Start searching and make sure the first byte sent requests the external clock
irq_disable(II_TIMER3);
REG_TM3CNT = 0;
REG_IF = (1 << II_TIMER3);
linkSPI->activate(LinkSPI::Mode::MASTER_256KBPS);
inData = 0xFF;
outData = 0x01;
nextOutData = 0x01;
globalStateCounter = 0;
subStateCounter = 0;
subStateChanged = false;
enterState = CLOCK_ACQUIRE;
exitState = CLOCK_ACQUIRE;
REG_TM3D = -DISCOVERY_TIMER_MIN;
REG_TM3CNT = TM_FREQ_1024 | TM_ENABLE;
break;
case PACKET_EXCHANGE:
@@ -299,7 +320,10 @@ void LinkConnection::startConnection(LinkState startState)
break;
}
enterState = startState;
if (startState != INITIAL_CONNECTION)
{
enterState = startState;
}
irq_enable(II_TIMER3);
}
@@ -420,15 +444,62 @@ void LinkConnection::handleStateLogic()
switch (enterState)
{
case INITIAL_CONNECTION:
nextOutData = 0xFF;
exitState = CLOCK;
nextOutData = 0x01;
exitState = DISCOVERY_RESET;
break;
case CLOCK:
case DISCOVERY_RESET:
// Reset and try a different timer phase
REG_TM3CNT = 0;
REG_IF = (1 << II_TIMER3);
linkSPI->activate(LinkSPI::Mode::MASTER_256KBPS);
outData = 0x01;
nextOutData = 0x01;
REG_TM3D = -(DISCOVERY_TIMER_MIN +
(globalStateCounter & DISCOVERY_TIMER_PHASE_MASK));
REG_TM3CNT = TM_FREQ_1024 | TM_ENABLE;
exitState = CLOCK_ACQUIRE;
break;
case CLOCK_ACQUIRE:
nextOutData = 0x01;
if (inData == 0x02)
{
// Receiving 0x02 while sending 0x01 means the other Game Boy offered
// external-clock mode and should now have selected the GBA as master.
REG_TM3D = -INITIAL_LINK_TIMER;
exitState = CLOCK_CONFIRM;
}
else if (inData == 0xFE)
{
// Keep compatibility with an already-established connection where the
// role-selection byte was completed before discovery began.
REG_TM3D = -INITIAL_LINK_TIMER;
exitState = SAVE_SUCCESS;
nextOutData = 0x01;
}
else if (subStateCounter >= DISCOVERY_TIMEOUT_TRANSFERS)
{
exitState = DISCOVERY_RESET;
}
else
{
REG_TM3D = -(DISCOVERY_TIMER_MIN +
(subStateCounter & DISCOVERY_TIMER_PHASE_MASK));
}
break;
case CLOCK_CONFIRM:
if (inData == 0xFE)
{
exitState = SAVE_SUCCESS;
nextOutData = 0x00;
nextOutData = 0x01;
}
else if (subStateCounter >= DISCOVERY_CONFIRM_TIMEOUT_TRANSFERS)
{
exitState = DISCOVERY_RESET;
nextOutData = 0x01;
}
else
{
@@ -437,12 +508,17 @@ void LinkConnection::handleStateLogic()
break;
case SAVE_SUCCESS:
if (inData == 0x60 || inData == 0x61)
nextOutData = 0x01;
if (inData == 0x02)
{
// Don't exit if we already set the GB as the follower
}
else if (inData == 0x60 || inData == 0x61)
{
exitState = MENU_OPEN;
nextOutData = inData;
}
// nextOutData defaults to 0x00
break;
case MENU_OPEN: