https://twitter.com/tsutsuii/status/1340512275958927361

hp425e-EVRX-tweaks.diff

--- /s/cvs/src/sys/arch/hp300/dev/sti_sgc.c	2020-12-19 10:35:47.860896348 +0900
+++ /s/netbsd-9/src/sys/arch/hp300/dev/sti_sgc.c	2020-12-20 13:42:55.710995744 +0900
@@ -49,31 +49,32 @@
 	struct sti_softc sc_sti;
 
 	paddr_t sc_bitmap;
-	bus_space_tag_t sc_bst;
-	bus_space_handle_t sc_ramdach;
 };
 
 /*
  * 425e EVRX specific hardware
  */
-#define STI_EVRX_RAMDACOFFSET	0x060000
-#define STI_EVRX_RAMDACSIZE	0x000800
+/*
+ * EVRX RAMDAC (Bt458) is found at offset 0x060000 from SGC bus PA and 
+ * offset 0x040000 length 0x1c0000 is mapped in MI sti via ROM regions 2
+ */
+#define STI_EVRX_REGNO2OFFSET	0x020000
 #define STI_EVRX_FBOFFSET	0x200000
 
-#define EVRX_BT458_ADDR		(0x200 + 2)
-#define EVRX_BT458_CMAP		(0x204 + 2)
-#define EVRX_BT458_CTRL		(0x208 + 2)
-#define EVRX_BT458_OMAP		(0x20C + 2)
+#define EVRX_BT458_ADDR		(STI_EVRX_REGNO2OFFSET + 0x200 + 2)
+#define EVRX_BT458_CMAP		(STI_EVRX_REGNO2OFFSET + 0x204 + 2)
+#define EVRX_BT458_CTRL		(STI_EVRX_REGNO2OFFSET + 0x208 + 2)
+#define EVRX_BT458_OMAP		(STI_EVRX_REGNO2OFFSET + 0x20C + 2)
 
 /* from HP-UX /usr/lib/libddevrx.a */
-#define EVRX_MAGIC00		0x600
-#define EVRX_MAGIC04		0x604
-#define EVRX_MAGIC08		0x608
-#define EVRX_MAGIC0C		0x60c
-#define EVRX_MAGIC10		0x610
+#define EVRX_MAGIC00		(STI_EVRX_REGNO2OFFSET + 0x600)
+#define EVRX_MAGIC04		(STI_EVRX_REGNO2OFFSET + 0x604)
+#define EVRX_MAGIC08		(STI_EVRX_REGNO2OFFSET + 0x608)
+#define EVRX_MAGIC0C		(STI_EVRX_REGNO2OFFSET + 0x60c)
+#define EVRX_MAGIC10		(STI_EVRX_REGNO2OFFSET + 0x610)
 #define EVRX_MAGIC10_BSY	0x00010000
-#define EVRX_MAGIC18		0x618
-#define EVRX_MAGIC1C		0x61c
+#define EVRX_MAGIC18		(STI_EVRX_REGNO2OFFSET + 0x618)
+#define EVRX_MAGIC1C		(STI_EVRX_REGNO2OFFSET + 0x61c)
 
 /*
  * HP A1659A CRX specific hardware
@@ -96,8 +97,8 @@
 
 /* 425e EVRX/CRX specific access functions */
 static int sti_evrx_putcmap(struct sti_screen *, u_int, u_int);
-static void sti_evrx_resetramdac(struct sti_sgc_softc *);
-static void sti_evrx_resetcmap(struct sti_sgc_softc *);
+static void sti_evrx_resetramdac(struct sti_screen *);
+static void sti_evrx_resetcmap(struct sti_screen *);
 static void sti_evrx_setupfb(struct sti_screen *);
 static paddr_t sti_m68k_mmap(void *, void *, off_t, int);
 
@@ -142,6 +143,7 @@
 	struct sti_softc *ssc = &sc->sc_sti;
 	struct sgc_attach_args *saa = aux;
 	struct sti_screen *scr;
+	bus_space_tag_t bst;
 	bus_space_handle_t romh;
 	bus_addr_t base;
 	struct wsemuldisplaydev_attach_args waa;
@@ -151,7 +153,7 @@
 	int i;
 
 	ssc->sc_dev = self;
-	sc->sc_bst = saa->saa_iot;
+	bst = saa->saa_iot;
 	base = (bus_addr_t)sgc_slottopa(saa->saa_slot);
 
 	if (saa->saa_slot == sticonslot) {
@@ -164,18 +166,18 @@
 
 		sti_describe(ssc);
 	} else {
-		if (bus_space_map(sc->sc_bst, base, PAGE_SIZE, 0, &romh)) {
+		if (bus_space_map(bst, base, PAGE_SIZE, 0, &romh)) {
 			aprint_error(": can't map ROM");
 			return;
 		}
 		/*
 		 * Compute real PROM size
 		 */
-		romend = sti_rom_size(sc->sc_bst, romh);
+		romend = sti_rom_size(bst, romh);
 
-		bus_space_unmap(sc->sc_bst, romh, PAGE_SIZE);
+		bus_space_unmap(bst, romh, PAGE_SIZE);
 
-		if (bus_space_map(sc->sc_bst, base, romend, 0, &romh)) {
+		if (bus_space_map(bst, base, romend, 0, &romh)) {
 			aprint_error(": can't map frame buffer");
 			return;
 		}
@@ -184,7 +186,7 @@
 		for (i = 0; i < STI_REGION_MAX; i++)
 			ssc->bases[i] = base;
 
-		if (sti_attach_common(ssc, sc->sc_bst, sc->sc_bst, romh,
+		if (sti_attach_common(ssc, bst, bst, romh,
 		    STI_CODEBASE_ALT) != 0)
 			return;
 	}
@@ -202,23 +204,13 @@
 		 */
 		sc->sc_bitmap = base + STI_EVRX_FBOFFSET;
 
-		/*
-		 * Bt458 RAMDAC can be accessed at offset +0x60200 and
-		 * unknown control registers are around +0x60600.
-		 */
-		if (bus_space_map(sc->sc_bst, base + STI_EVRX_RAMDACOFFSET,
-		    STI_EVRX_RAMDACSIZE, 0, &sc->sc_ramdach)) {
-			aprint_error_dev(self, "can't map RAMDAC\n");
-			return;
-		}
-
 		aprint_normal_dev(self, "Enable mmap support\n");
 
 		/*
 		 * initialize Bt458 RAMDAC and preserve initial color map
 		 */
-		sti_evrx_resetramdac(sc);
-		sti_evrx_resetcmap(sc);
+		sti_evrx_resetramdac(scr);
+		sti_evrx_resetcmap(scr);
 
 		scr->setupfb = sti_evrx_setupfb;
 		scr->putcmap = sti_evrx_putcmap;
@@ -289,10 +281,8 @@
 sti_evrx_putcmap(struct sti_screen *scr, u_int index, u_int count)
 {
 	struct sti_rom *rom = scr->scr_rom;
-	struct sti_softc *ssc = rom->rom_softc;
-	struct sti_sgc_softc *sc = device_private(ssc->sc_dev);
-	bus_space_tag_t bst = sc->sc_bst;
-	bus_space_handle_t bsh = sc->sc_ramdach;
+	bus_space_tag_t bst = rom->memt;
+	bus_space_handle_t bsh = rom->regh[2];
 	int i;
 
 	/* magic setup from HP-UX */
@@ -312,10 +302,11 @@
 }
 
 static void
-sti_evrx_resetramdac(struct sti_sgc_softc *sc)
+sti_evrx_resetramdac(struct sti_screen *scr)
 {
-	bus_space_tag_t bst = sc->sc_bst;
-	bus_space_handle_t bsh = sc->sc_ramdach;
+	struct sti_rom *rom = scr->scr_rom;
+	bus_space_tag_t bst = rom->memt;
+	bus_space_handle_t bsh = rom->regh[2];
 #if 0
 	int i;
 #endif
@@ -361,12 +352,11 @@
 }
 
 static void
-sti_evrx_resetcmap(struct sti_sgc_softc *sc)
+sti_evrx_resetcmap(struct sti_screen *scr)
 {
-	struct sti_softc *ssc = &sc->sc_sti;
-	struct sti_screen *scr = ssc->sc_scr;
-	bus_space_tag_t bst = sc->sc_bst;
-	bus_space_handle_t bsh = sc->sc_ramdach;
+	struct sti_rom *rom = scr->scr_rom;
+	bus_space_tag_t bst = rom->memt;
+	bus_space_handle_t bsh = rom->regh[2];
 	int i;
 
 	/* magic setup from HP-UX */
@@ -389,12 +379,9 @@
 static void
 sti_evrx_setupfb(struct sti_screen *scr)
 {
-	struct sti_rom *rom = scr->scr_rom;
-	struct sti_softc *ssc = rom->rom_softc;
-	struct sti_sgc_softc *sc = device_private(ssc->sc_dev);
 
 	sti_init(scr, 0);
-	sti_evrx_resetramdac(sc);
+	sti_evrx_resetramdac(scr);
 }
 
 static paddr_t