machine/mediagx_host: move VGA to own core

scripts/src/video.lua

@@ -895,6 +895,18 @@ if (VIDEOS["PC_VGA_MATROX"]~=null) then
 	}
 end
 
+--------------------------------------------------
+--
+--@src/devices/video/pc_vga_mediagx.h,VIDEOS["PC_VGA_MEDIAGX"] = true
+--------------------------------------------------
+
+if (VIDEOS["PC_VGA_MEDIAGX"]~=null) then
+	files {
+		MAME_DIR .. "src/devices/video/pc_vga_mediagx.cpp",
+		MAME_DIR .. "src/devices/video/pc_vga_mediagx.h",
+	}
+end
+
 --------------------------------------------------
 --
 --@src/devices/video/pc_vga_nvidia.h,VIDEOS["PC_VGA_NVIDIA"] = true

src/devices/machine/mediagx_host.cpp

@@ -4,10 +4,6 @@
 
 MediaGX host implementation (northbridge)
 
-TODO:
-- Currently cheat around software VGA, MediaGX notoriously triggers SMI for every access to
-  VGA legacy ranges, which is horrible both for emulation purposes and for performance.
-
 **************************************************************************************************/
 
 #include "emu.h"
@@ -119,6 +115,7 @@ void mediagx_host_device::device_start()
 	io_offset       = 0;
 
 	m_ram.resize(m_ram_size/4);
+	m_smm_ram.resize(SMM_SIZE/4);
 }
 
 void mediagx_host_device::device_reset()
@@ -143,10 +140,9 @@ void mediagx_host_device::device_add_mconfig(machine_config &config)
 {
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER));
 	screen.set_raw(XTAL(25'174'800), 900, 0, 640, 526, 0, 480);
-	screen.set_screen_update(m_vga, FUNC(vga_device::screen_update));
+	screen.set_screen_update(m_vga, FUNC(mediagx_vga_device::screen_update));
 
-	// HACK: needs an interruptible x86 core to even try.
+	MEDIAGX_VGA(config, m_vga, 0);
-	VGA(config, m_vga, 0);
 	m_vga->set_screen("screen");
 	m_vga->set_vram_size(4*1024*1024);
 }
@@ -217,6 +213,7 @@ void mediagx_host_device::map_extra(
 	);
 
 	memory_space->install_ram(0x00000000, 0x0009ffff, &m_ram[0x00000000/4]);
+	// TODO: BC_XMAP_1, which is always 0 in both astropc and matrix (???)
 	//memory_space->install_ram(0x000a0000, 0x000bffff, &m_ram[0x000a0000/4]);
 	memory_space->install_device(0x000a0000, 0x000bffff, *this, &mediagx_host_device::legacy_memory_map);
 	io_space->install_device(0x03b0, 0x03df, *this, &mediagx_host_device::legacy_io_map);
@@ -261,7 +258,7 @@ void mediagx_host_device::map_extra(
 
 	if (gx_base)
 	{
-		LOG("gxbase mapped at %08x\n", gx_base);
+		LOGMAP("gxbase mapped at %08x\n", gx_base);
 		memory_space->install_device(gx_base, (gx_base) | 0xffffff, *this, &mediagx_host_device::gxbase_map);
 	}
 }
@@ -269,12 +266,22 @@ void mediagx_host_device::map_extra(
 void mediagx_host_device::gxbase_map(address_map &map)
 {
 //  0x001000 scratchpad
-//  0x008000 Internal bus I/F Unit
+	map(0x008000, 0x008003).lrw32(
+		NAME([this] (offs_t offset) {
+			return m_bc_dram_top;
+		}),
+		NAME([this] (offs_t offset, u32 data, u32 mem_mask) {
+			LOG("GXBASE+%04x: BC_DRAM_TOP %08x & %08x\n", (offset * 4) + 0x8000, data, mem_mask);
+			COMBINE_DATA(&m_bc_dram_top);
+			remap_cb();
+		})
+	);
 	map(0x008004, 0x00800f).lrw32(
 		NAME([this] (offs_t offset) {
 			return m_bc_xmap[offset];
 		}),
 		NAME([this] (offs_t offset, u32 data, u32 mem_mask) {
+			LOG("GXBASE+%04x: BC_XMAP_%d %08x & %08x\n", (offset * 4) + 0x8004, offset + 1, data, mem_mask);
 			COMBINE_DATA(&m_bc_xmap[offset]);
 			remap_cb();
 		})
@@ -283,7 +290,11 @@ void mediagx_host_device::gxbase_map(address_map &map)
 	map(0x008300, 0x0083ff).m(*this, FUNC(mediagx_host_device::display_ctrl_map));
 //  0x008400 Memory controller
 //  0x008500 Power Management
-//  0x400000 SMM System Code
+	// SMM System Code
+	map(0x400000, 0x41ffff).lrw32(
+		NAME([this] (offs_t offset) { return m_smm_ram[offset]; }),
+		NAME([this] (offs_t offset, u32 data, u32 mem_mask) { COMBINE_DATA(&m_smm_ram[offset]); })
+	);
 //  0x800000 GFX memory
 }
 
@@ -350,15 +361,15 @@ void mediagx_host_device::legacy_memory_map(address_map &map)
 
 void mediagx_host_device::legacy_io_map(address_map &map)
 {
-	map(0x000, 0x02f).m(m_vga, FUNC(vga_device::io_map));
+	map(0x000, 0x02f).m(m_vga, FUNC(mediagx_vga_device::io_map));
 }
 
 uint8_t mediagx_host_device::vram_r(offs_t offset)
 {
-	return downcast<vga_device *>(m_vga.target())->mem_r(offset);
+	return downcast<mediagx_vga_device *>(m_vga.target())->mem_r(offset);
 }
 
 void mediagx_host_device::vram_w(offs_t offset, uint8_t data)
 {
-	downcast<vga_device *>(m_vga.target())->mem_w(offset, data);
+	downcast<mediagx_vga_device *>(m_vga.target())->mem_w(offset, data);
 }

src/devices/machine/mediagx_host.h

@@ -7,7 +7,7 @@
 #pragma once
 
 #include "pci.h"
-#include "video/pc_vga.h"
+#include "video/pc_vga_mediagx.h"
 
 class mediagx_host_device : public pci_host_device
 {
@@ -44,8 +44,9 @@ private:
 		AS_PCI_IO = 2
 	};
 	required_device<cpu_device> m_host_cpu;
-	required_device<vga_device> m_vga;
+	required_device<mediagx_vga_device> m_vga;
 	std::vector<uint32_t> m_ram;
+	std::vector<uint32_t> m_smm_ram;
 	address_space_config  m_superio_space_config;
 
 	void superio_map(address_map &map);
@@ -58,7 +59,9 @@ private:
 		u8 gcr = 0;
 	}m_superio;
 
-	int m_ram_size = 0;
+	u32 m_ram_size = 0;
+	// FIXME: check size
+	static constexpr u32 SMM_SIZE = 0x20000;
 	u8 m_pci_control[2]{};
 	u8 m_pci_arbitration[2]{};
 
@@ -66,6 +69,7 @@ private:
 	void gfx_pipeline_map(address_map &map);
 	void display_ctrl_map(address_map &map);
 
+	u32 m_bc_dram_top = 0;
 	u32 m_bc_xmap[3]{};
 
 	void legacy_memory_map(address_map &map);

src/devices/video/pc_vga_mediagx.cpp

@@ -0,0 +1,57 @@
+// license:BSD-3-Clause
+// copyright-holders: Angelo Salese
+/**************************************************************************************************
+
+MediaGX VGA virtual interface
+
+TODO:
+- Currently cheat around software VGA, MediaGX notoriously triggers SMI for every access to
+  VGA legacy ranges, which is horrible both for emulation purposes and for performance.
+- A good benchmark about fixing pc_vga infrastructure:
+  it connects thru a VGA connector anyway & it has VGA features (DDC, HW cursor, BitBLT)
+
+**************************************************************************************************/
+
+#include "emu.h"
+#include "pc_vga_mediagx.h"
+
+#include "screen.h"
+
+#define VERBOSE (LOG_GENERAL)
+//#define LOG_OUTPUT_FUNC osd_printf_info
+#include "logmacro.h"
+
+DEFINE_DEVICE_TYPE(MEDIAGX_VGA,  mediagx_vga_device,  "mediagx_vga",  "MediaGX Virtual VGA i/f")
+
+mediagx_vga_device::mediagx_vga_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+	: svga_device(mconfig, MEDIAGX_VGA, tag, owner, clock)
+{
+	m_crtc_space_config = address_space_config("crtc_regs", ENDIANNESS_LITTLE, 8, 8, 0, address_map_constructor(FUNC(mediagx_vga_device::crtc_map), this));
+}
+
+void mediagx_vga_device::device_start()
+{
+	svga_device::device_start();
+}
+
+void mediagx_vga_device::device_reset()
+{
+	svga_device::device_reset();
+}
+
+void mediagx_vga_device::crtc_map(address_map &map)
+{
+	svga_device::crtc_map(map);
+	// astropc.cpp read this at boot, DDC?
+	map(0x3e, 0x3e).lr8(NAME([] () { return 0xff; }));
+}
+
+uint8_t mediagx_vga_device::mem_r(offs_t offset)
+{
+	return svga_device::mem_r(offset);
+}
+
+void mediagx_vga_device::mem_w(offs_t offset, uint8_t data)
+{
+	svga_device::mem_w(offset, data);
+}

src/devices/video/pc_vga_mediagx.h

@@ -0,0 +1,37 @@
+// license:BSD-3-Clause
+// copyright-holders: Angelo Salese
+
+#ifndef MAME_VIDEO_PC_VGA_MEDIAGX_H
+#define MAME_VIDEO_PC_VGA_MEDIAGX_H
+
+#pragma once
+
+#include "video/pc_vga.h"
+
+#include "screen.h"
+
+
+class mediagx_vga_device :  public svga_device
+{
+public:
+	static constexpr feature_type imperfect_features() { return feature::GRAPHICS; }
+
+	mediagx_vga_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+
+	virtual uint8_t mem_r(offs_t offset) override;
+	virtual void mem_w(offs_t offset, uint8_t data) override;
+
+protected:
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+	virtual void crtc_map(address_map &map) override;
+
+//	virtual ioport_constructor device_input_ports() const override;
+
+private:
+};
+
+DECLARE_DEVICE_TYPE(MEDIAGX_VGA, mediagx_vga_device)
+
+#endif // MAME_VIDEO_PC_VGA_MEDIAGX_H