From f6e208267e6d4b61f2ef72dcc7d681f3d5e09670 Mon Sep 17 00:00:00 2001
From: Maxim Poliakovski <maximumspatium@googlemail.com>
Date: Mon, 19 Dec 2022 01:28:16 +0100
Subject: [PATCH] bandit: more config space registers.

---
 devices/common/pci/bandit.cpp | 28 +++++++++++++++++++++++++++-
 devices/common/pci/bandit.h   |  6 +++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/devices/common/pci/bandit.cpp b/devices/common/pci/bandit.cpp
index 1ec1c7d..9056e81 100644
--- a/devices/common/pci/bandit.cpp
+++ b/devices/common/pci/bandit.cpp
@@ -73,6 +73,11 @@ Bandit::Bandit(int bridge_num, std::string name, int dev_id, int rev)
     // that correspond to the 32MB assigned PCI address space of this Bandit.
     // This initialization is implied by the device functionality.
     this->addr_mask = 3 << ((bridge_num & 3) * 2);
+
+    // initial PCI number + chip mode: big endian, interrupts & VGA space disabled
+    this->mode_ctrl = ((bridge_num & 3) << 2) | 3;
+
+    this->rd_hold_off_cnt = 8;
 }
 
 uint32_t Bandit::pci_cfg_read(uint32_t reg_offs, uint32_t size)
@@ -84,6 +89,10 @@ uint32_t Bandit::pci_cfg_read(uint32_t reg_offs, uint32_t size)
     switch (reg_offs) {
     case BANDIT_ADDR_MASK:
         return BYTESWAP_32(this->addr_mask);
+    case BANDIT_MODE_SELECT:
+        return BYTESWAP_32(this->mode_ctrl);
+    case BANDIT_ARBUS_RD_HOLD_OFF:
+        return BYTESWAP_32(this->rd_hold_off_cnt);
     default:
         LOG_F(WARNING, "%s: reading from unimplemented config register at 0x%X",
               this->pci_name.c_str(), reg_offs);
@@ -99,11 +108,24 @@ void Bandit::pci_cfg_write(uint32_t reg_offs, uint32_t value, uint32_t size)
         return;
     }
 
+    if (size == 4) {
+        value = BYTESWAP_32(value);
+    } else {
+        LOG_F(WARNING, "%s: non-DWORD writes to the control registers not supported",
+            this->pci_name.c_str());
+    }
+
     switch (reg_offs) {
     case BANDIT_ADDR_MASK:
-        this->addr_mask = BYTESWAP_32(value);
+        this->addr_mask = value;
         this->verbose_address_space();
         break;
+    case BANDIT_MODE_SELECT:
+        this->mode_ctrl = value;
+        break;
+    case BANDIT_ARBUS_RD_HOLD_OFF:
+        this->rd_hold_off_cnt =  value & 0x1F;
+        break;
     default:
         LOG_F(WARNING, "%s: writing to unimplemented config register at 0x%X",
               this->pci_name.c_str(), reg_offs);
@@ -251,6 +273,10 @@ void Bandit::verbose_address_space()
     uint32_t mask;
     int bit_pos;
 
+    if (!this->addr_mask) {
+        return;
+    }
+
     LOG_F(INFO, "%s address spaces:", this->pci_name.c_str());
 
     // verbose coarse aka 256MB memory regions
diff --git a/devices/common/pci/bandit.h b/devices/common/pci/bandit.h
index 6905e0b..cbd4ebf 100644
--- a/devices/common/pci/bandit.h
+++ b/devices/common/pci/bandit.h
@@ -44,7 +44,9 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 /** Bandit specific configuration registers. */
 enum {
-    BANDIT_ADDR_MASK = 0x48,
+    BANDIT_ADDR_MASK            = 0x48,
+    BANDIT_MODE_SELECT          = 0x50,
+    BANDIT_ARBUS_RD_HOLD_OFF    = 0x58,
 };
 
 /** checks if one bit is set at time, return 0 if not */
@@ -77,6 +79,8 @@ private:
     uint32_t    base_addr;
     uint32_t    config_addr;
     uint32_t    addr_mask;
+    uint32_t    mode_ctrl; // controls various chip modes/features
+    uint32_t    rd_hold_off_cnt;
 };
 
 /** Chaos is a custom ARBus-to-PCI bridge that provides a specialized