# --- T2-COPYRIGHT-BEGIN ---
# t2/package/*/xf86-video-openchrome/hotfix-cle266-hwcursor.patch
# Copyright (C) 2026 The T2 SDE Project
# SPDX-License-Identifier: GPL-2.0 or patched project license
# --- T2-COPYRIGHT-END ---

CLE266 / KM400? (UniChrome) hardware cursor not visible. The driver drove
them through the Hardware Icon (HI) engine, but these chipsets use a
earlier gen 32x32 two-color cursor engine.

Restore support for CLE266 / KM400? monochrome cursor engine.

Signed-off-by: René Rebe <rene@exactco.de>

--- xf86-video-openchrome.git/src/via_driver.c
+++ xf86-video-openchrome.git/src/via_driver.c
@@ -1562,7 +1562,16 @@
         switch (pVia->Chipset) {
         case VIA_CLE266:
         case VIA_KM400:
-            flags = 0;
+            /* CLE266 and KM400 (UniChrome) use a dedicated 32x32 two-color
+             * cursor engine (registers 0x2D0-0x2E0) that does not support an
+             * ARGB cursor.  Request a monochrome source/mask cursor in the
+             * layout that engine expects. */
+            cursorWidth = cursorHeight = 32;
+            flags = HARDWARE_CURSOR_SOURCE_MASK_INTERLEAVE_32 |
+                    HARDWARE_CURSOR_AND_SOURCE_WITH_MASK |
+                    HARDWARE_CURSOR_TRUECOLOR_AT_8BPP |
+                    HARDWARE_CURSOR_INVERT_MASK |
+                    HARDWARE_CURSOR_BIT_ORDER_MSBFIRST;
             break;
         default:
             flags = HARDWARE_CURSOR_AND_SOURCE_WITH_MASK |
--- xf86-video-openchrome.git/src/via_eng_regs.h
+++ xf86-video-openchrome.git/src/via_eng_regs.h
@@ -153,6 +153,16 @@
 #define V1_STARTADDR_CR1        0x2F4
 #define V1_STARTADDR_CR2        0x2F8
 #define V1_STARTADDR_CR3        0x2FC
+
+/* CLE266 / KM400 (UniChrome) dedicated hardware cursor engine registers.
+ * These older chipsets do not use the Hardware Icon (HI) engine below;
+ * the cursor is a 32x32 two-color cursor driven through this register set. */
+#define VIA_REG_CURSOR_MODE	0x2D0	/* cursor base address + control[1:0] */
+#define VIA_REG_CURSOR_POS	0x2D4	/* (x << 16) | y */
+#define VIA_REG_CURSOR_ORG	0x2D8	/* (xoff << 16) | yoff */
+#define VIA_REG_CURSOR_BG	0x2DC	/* background color */
+#define VIA_REG_CURSOR_FG	0x2E0	/* foreground color */
+
 /*CN400 and older Hardware Icon engine register*/
 #define HI_POSSTART		0x208
 #define HI_CENTEROFFSET		0x20C
--- xf86-video-openchrome.git/src/via_display.c
+++ xf86-video-openchrome.git/src/via_display.c
@@ -3405,13 +3405,32 @@
     HARDWARE_CURSOR_TRUECOLOR_AT_8BPP flag is set.  In that case
     and in all other bpps the fg and bg are in 8-8-8 RGB format.
 */
+/*
+ * CLE266 and KM400? (UniChrome) use a dedicated 32x32 two-color hardware
+ * cursor engine (registers 0x2D0-0x2E0) rather than the Hardware Icon (HI)
+ * engine used by later chipsets.
+ */
+static Bool
+viaCursorOldEngine(VIAPtr pVia)
+{
+    return (pVia->Chipset == VIA_CLE266) || (pVia->Chipset == VIA_KM400);
+}
+
 static void
 iga_crtc_set_cursor_colors(xf86CrtcPtr crtc, int bg, int fg)
 {
     ScrnInfoPtr pScrn = crtc->scrn;
+    VIAPtr pVia = VIAPTR(pScrn);
     drmmode_crtc_private_ptr iga = crtc->driver_private;
     xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
 
+    if (viaCursorOldEngine(pVia)) {
+        /* Two-color cursor: foreground / background come from registers. */
+        VIASETREG(VIA_REG_CURSOR_BG, bg);
+        VIASETREG(VIA_REG_CURSOR_FG, fg);
+        return;
+    }
+
     if (xf86_config->cursor_fg)
         return;
 
@@ -3437,6 +3456,7 @@
 iga_crtc_set_cursor_position(xf86CrtcPtr crtc, int x, int y)
 {
     ScrnInfoPtr pScrn = crtc->scrn;
+    VIAPtr pVia = VIAPTR(pScrn);
     drmmode_crtc_private_ptr iga = crtc->driver_private;
     unsigned xoff, yoff;
 
@@ -3454,6 +3474,18 @@
         yoff = 0;
     }
 
+    if (viaCursorOldEngine(pVia)) {
+        CARD32 mode = VIAGETREG(VIA_REG_CURSOR_MODE);
+
+        /* Hide the cursor while moving it to avoid a ghosting hardware
+         * bug, then restore the previous enable state. */
+        VIASETREG(VIA_REG_CURSOR_MODE, mode & 0xFFFFFFFE);
+        VIASETREG(VIA_REG_CURSOR_ORG, ((xoff << 16) | (yoff & 0x003f)));
+        VIASETREG(VIA_REG_CURSOR_POS, ((x << 16) | (y & 0x07ff)));
+        VIASETREG(VIA_REG_CURSOR_MODE, mode);
+        return;
+    }
+
     if (!iga->index) {
         viaIGA1SetHIDisplayLocation(pScrn, x, xoff, y, yoff);
     } else {
@@ -3465,8 +3497,15 @@
 iga_crtc_show_cursor(xf86CrtcPtr crtc)
 {
     ScrnInfoPtr pScrn = crtc->scrn;
+    VIAPtr pVia = VIAPTR(pScrn);
     drmmode_crtc_private_ptr iga = crtc->driver_private;
 
+    if (viaCursorOldEngine(pVia)) {
+        VIASETREG(VIA_REG_CURSOR_MODE,
+                  VIAGETREG(VIA_REG_CURSOR_MODE) | 0x03);
+        return;
+    }
+
     if (!iga->index) {
         viaIGA1DisplayHI(pScrn, TRUE);
     } else {
@@ -3478,8 +3517,15 @@
 iga_crtc_hide_cursor(xf86CrtcPtr crtc)
 {
     ScrnInfoPtr pScrn = crtc->scrn;
+    VIAPtr pVia = VIAPTR(pScrn);
     drmmode_crtc_private_ptr iga = crtc->driver_private;
 
+    if (viaCursorOldEngine(pVia)) {
+        VIASETREG(VIA_REG_CURSOR_MODE,
+                  VIAGETREG(VIA_REG_CURSOR_MODE) & 0xFFFFFFFE);
+        return;
+    }
+
     if (!iga->index) {
         viaIGA1DisplayHI(pScrn, FALSE);
     } else {
@@ -3508,6 +3554,48 @@
     }
 }
 
+/*
+ * Upload a two-color cursor image for the CLE266 / KM400 UniChrome cursor
+ * engine.  The X server hands us a 32x32 two-plane (AND source + mask) image
+ * (256 bytes) which is copied verbatim into video RAM, and the cursor engine
+ * is pointed at it via VIA_REG_CURSOR_MODE (byte offset in the low address
+ * bits, cursor control in bits [1:0]).
+ */
+static void
+iga_crtc_load_cursor_image(xf86CrtcPtr crtc, CARD8 *image)
+{
+    ScrnInfoPtr pScrn = crtc->scrn;
+    VIAPtr pVia = VIAPTR(pScrn);
+    drmmode_crtc_private_ptr iga = crtc->driver_private;
+    void *dst;
+    /* 32x32, two planes (AND + XOR), 1 bit per pixel per plane. */
+    unsigned int monoSize = 2 * (32 / 8) * 32;
+    CARD32 mode;
+
+    if (!viaCursorOldEngine(pVia)) {
+        return;
+    }
+
+    if (monoSize > iga->cursor_bo->size) {
+        monoSize = iga->cursor_bo->size;
+    }
+
+    mode = VIAGETREG(VIA_REG_CURSOR_MODE);
+
+    /* Disable the cursor engine while its image is replaced. */
+    VIASETREG(VIA_REG_CURSOR_MODE, mode & 0xFFFFFFFE);
+
+    dst = drm_bo_map(pScrn, iga->cursor_bo);
+    memset(dst, 0x00, iga->cursor_bo->size);
+    memcpy(dst, image, monoSize);
+    drm_bo_unmap(pScrn, iga->cursor_bo);
+
+    /* Point the engine at the image (byte offset in video RAM) while
+     * preserving the current enable / control bits. */
+    VIASETREG(VIA_REG_CURSOR_MODE,
+              (iga->cursor_bo->offset & 0xFFFFFFFC) | (mode & 0x03));
+}
+
 static void
 iga_crtc_destroy(xf86CrtcPtr crtc)
 {
@@ -3533,6 +3621,7 @@
     .set_cursor_position    = iga_crtc_set_cursor_position,
     .show_cursor            = iga_crtc_show_cursor,
     .hide_cursor            = iga_crtc_hide_cursor,
+    .load_cursor_image      = iga_crtc_load_cursor_image,
     .load_cursor_argb       = iga_crtc_load_cursor_argb,
 #if GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) > 2
     .set_origin             = iga1_crtc_set_origin,
@@ -3846,6 +3935,7 @@
     .set_cursor_position    = iga_crtc_set_cursor_position,
     .show_cursor            = iga_crtc_show_cursor,
     .hide_cursor            = iga_crtc_hide_cursor,
+    .load_cursor_image      = iga_crtc_load_cursor_image,
     .load_cursor_argb       = iga_crtc_load_cursor_argb,
 #if GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) > 2
     .set_origin             = iga2_crtc_set_origin,