From 1c077097279bad89ae93c7e2145b633995501252 Mon Sep 17 00:00:00 2001
From: Jonathan Campbell <jonathan@castus.tv>
Date: Sun, 4 May 2025 22:23:26 -0700
Subject: [PATCH] Add integration device commands to read CPU cycle count and
 info

---
 include/iglib.h   |  8 ++++++++
 src/ints/bios.cpp | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/iglib.h b/include/iglib.h
index f56a56e19..87e99011c 100644
--- a/include/iglib.h
+++ b/include/iglib.h
@@ -112,6 +112,14 @@ extern uint16_t DOSBOXID_VAR dosbox_id_baseio;
 
 #define DOSBOX_ID_REG_INJECT_NMI                        (0x00808602UL)
 
+#define DOSBOX_ID_REG_CPU_CYCLES                        (0x55504300UL)  /* fixed cycle count, which may vary if max or auto */
+#define DOSBOX_ID_REG_CPU_MAX_PERCENT                   (0x55504301UL)  /* for max cycles, percentage from 0 to 100 */
+#define DOSBOX_ID_REG_CPU_CYCLES_INFO                   (0x55504302UL)  /* info about cycles, including fixed, auto, max */
+# define DOSBOX_ID_REG_CPU_CYCLES_INFO_MODE_MASK        (0xFUL << 0UL)
+# define DOSBOX_ID_REG_CPU_CYCLES_INFO_FIXED            (1UL << 0UL)
+# define DOSBOX_ID_REG_CPU_CYCLES_INFO_MAX              (2UL << 0UL)
+# define DOSBOX_ID_REG_CPU_CYCLES_INFO_AUTO             (3UL << 0UL)
+
 #define DOSBOX_ID_REG_8237_INJECT_WRITE                 (0x00823700UL)
 #define DOSBOX_ID_REG_8237_INJECT_READ                  (0x00823780UL)
 
diff --git a/src/ints/bios.cpp b/src/ints/bios.cpp
index be003f83c..036fb84ac 100644
--- a/src/ints/bios.cpp
+++ b/src/ints/bios.cpp
@@ -873,6 +873,27 @@ void dosbox_integration_trigger_read() {
 		case DOSBOX_ID_RESET_INDEX_CODE: /* interface reset result */
 			break;
 
+		case DOSBOX_ID_REG_CPU_CYCLES:
+			if (CPU_CycleMax < 0x80000000)
+				dosbox_int_register = (uint32_t)CPU_CycleMax;
+			else
+				dosbox_int_register = (uint32_t)0x7FFFFFFFUL;
+			break;
+
+		case DOSBOX_ID_REG_CPU_MAX_PERCENT:
+			dosbox_int_register = CPU_CyclePercUsed;
+			break;
+
+		case DOSBOX_ID_REG_CPU_CYCLES_INFO:
+			dosbox_int_register = 0;
+			if (CPU_CycleAutoAdjust)
+			       dosbox_int_register |= DOSBOX_ID_REG_CPU_CYCLES_INFO_MAX;
+			else if (CPU_AutoDetermineMode &CPU_AUTODETERMINE_CYCLES)
+			       dosbox_int_register |= DOSBOX_ID_REG_CPU_CYCLES_INFO_AUTO;
+			else
+			       dosbox_int_register |= DOSBOX_ID_REG_CPU_CYCLES_INFO_FIXED;
+			break;
+
 		default:
 			dosbox_int_register = 0xAA55AA55;
 			dosbox_int_error = true;