From 3aad040f289f402417e931c0b1f26c69fe9fd04a Mon Sep 17 00:00:00 2001
From: Maxim Poliakovski <maximumspatium@googlemail.com>
Date: Sun, 21 Apr 2024 22:56:08 +0200
Subject: [PATCH] mesh: improve exception register emulation.

---
 devices/common/scsi/mesh.cpp | 28 ++++++++++++----------------
 devices/common/scsi/mesh.h   |  4 ++--
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/devices/common/scsi/mesh.cpp b/devices/common/scsi/mesh.cpp
index 37e4106..c279058 100644
--- a/devices/common/scsi/mesh.cpp
+++ b/devices/common/scsi/mesh.cpp
@@ -33,8 +33,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 using namespace MeshScsi;
 
-int MeshController::device_postinit()
-{
+int MeshController::device_postinit() {
     this->bus_obj = dynamic_cast<ScsiBus*>(gMachineObj->get_comp_by_name("ScsiMesh"));
 
     this->int_ctrl = dynamic_cast<InterruptCtrl*>(
@@ -44,11 +43,11 @@ int MeshController::device_postinit()
     return 0;
 }
 
-void MeshController::reset(bool is_hard_reset)
-{
+void MeshController::reset(bool is_hard_reset) {
     this->cur_cmd       = SeqCmd::NoOperation;
     this->fifo_cnt      = 0;
     this->int_mask      = 0;
+    this->exception     = 0;
     this->xfer_count    = 0;
     this->src_id        = 7;
 
@@ -58,8 +57,7 @@ void MeshController::reset(bool is_hard_reset)
     }
 }
 
-uint8_t MeshController::read(uint8_t reg_offset)
-{
+uint8_t MeshController::read(uint8_t reg_offset) {
     switch(reg_offset) {
     case MeshReg::XferCount0:
         return this->xfer_count & 0xFFU;
@@ -74,7 +72,7 @@ uint8_t MeshController::read(uint8_t reg_offset)
     case MeshReg::FIFOCount:
         return this->fifo_cnt;
     case MeshReg::Exception:
-        return 0;
+        return this->exception;
     case MeshReg::Error:
         return 0;
     case MeshReg::IntMask:
@@ -94,8 +92,7 @@ uint8_t MeshController::read(uint8_t reg_offset)
     return 0;
 }
 
-void MeshController::write(uint8_t reg_offset, uint8_t value)
-{
+void MeshController::write(uint8_t reg_offset, uint8_t value) {
     uint16_t new_stat;
 
     switch(reg_offset) {
@@ -141,19 +138,20 @@ void MeshController::write(uint8_t reg_offset, uint8_t value)
     }
 }
 
-void MeshController::perform_command(const uint8_t cmd)
-{
+void MeshController::perform_command(const uint8_t cmd) {
     this->cur_cmd = cmd;
 
     this->int_stat &= ~INT_CMD_DONE;
 
     switch (this->cur_cmd & 0xF) {
     case SeqCmd::Arbitrate:
+        this->exception &= EXC_ARB_LOST;
         this->bus_obj->release_ctrl_lines(this->src_id);
         this->cur_state = SeqState::BUS_FREE;
         this->sequencer();
         break;
     case SeqCmd::Select:
+        this->exception &= EXC_SEL_TIMEOUT;
         this->cur_state = SeqState::SEL_BEGIN;
         this->sequencer();
         break;
@@ -162,7 +160,7 @@ void MeshController::perform_command(const uint8_t cmd)
         this->int_stat |= INT_CMD_DONE;
         break;
     case SeqCmd::EnaReselect:
-        LOG_F(INFO, "MESH: EnaReselect stub invoked");
+        LOG_F(9, "MESH: EnaReselect stub invoked");
         this->int_stat |= INT_CMD_DONE;
         break;
     case SeqCmd::DisReselect:
@@ -182,8 +180,7 @@ void MeshController::perform_command(const uint8_t cmd)
     }
 }
 
-void MeshController::seq_defer_state(uint64_t delay_ns)
-{
+void MeshController::seq_defer_state(uint64_t delay_ns) {
     seq_timer_id = TimerManager::get_instance()->add_oneshot_timer(
         delay_ns,
         [this]() {
@@ -254,8 +251,7 @@ void MeshController::sequencer()
     }
 }
 
-void MeshController::update_irq()
-{
+void MeshController::update_irq() {
     uint8_t new_irq = !!(this->int_stat & this->int_mask);
     if (new_irq != this->irq) {
         this->irq = new_irq;
diff --git a/devices/common/scsi/mesh.h b/devices/common/scsi/mesh.h
index 2a5a20b..31c7c72 100644
--- a/devices/common/scsi/mesh.h
+++ b/devices/common/scsi/mesh.h
@@ -157,7 +157,7 @@ protected:
 
 private:
     uint8_t     chip_id;
-    uint8_t     int_mask;
+    uint8_t     int_mask = 0;
     uint8_t     int_stat = 0;
     uint8_t     sync_params;
     uint8_t     src_id;
@@ -165,7 +165,7 @@ private:
     uint8_t     cur_cmd;
     uint8_t     error;
     uint8_t     fifo_cnt;
-    uint8_t     exception;
+    uint8_t     exception = 0;
     uint32_t    xfer_count;
 
     ScsiBus*    bus_obj;