This is a BIOS emulator, porting from SciTech for u-boot, mainly for
ATI video card BIOS. and can be used for x86 code emulation by some
modifications.

Signed-off-by: Jason Jin <Jason.jin@freescale.com>
diff --git a/drivers/bios_emulator/atibios.c b/drivers/bios_emulator/atibios.c
new file mode 100644
index 0000000..084339c
--- /dev/null
+++ b/drivers/bios_emulator/atibios.c
@@ -0,0 +1,340 @@
+/****************************************************************************
+*
+*                    Video BOOT Graphics Card POST Module
+*
+*  ========================================================================
+*   Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+*   Jason Jin <Jason.jin@freescale.com>
+*
+*   Copyright (C) 1991-2004 SciTech Software, Inc. All rights reserved.
+*
+*   This file may be distributed and/or modified under the terms of the
+*   GNU General Public License version 2.0 as published by the Free
+*   Software Foundation and appearing in the file LICENSE.GPL included
+*   in the packaging of this file.
+*
+*   Licensees holding a valid Commercial License for this product from
+*   SciTech Software, Inc. may use this file in accordance with the
+*   Commercial License Agreement provided with the Software.
+*
+*   This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
+*   THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+*   PURPOSE.
+*
+*   See http://www.scitechsoft.com/license/ for information about
+*   the licensing options available and how to purchase a Commercial
+*   License Agreement.
+*
+*   Contact license@scitechsoft.com if any conditions of this licensing
+*   are not clear to you, or you have questions about licensing options.
+*
+*  ========================================================================
+*
+* Language:     ANSI C
+* Environment:  Linux Kernel
+* Developer:    Kendall Bennett
+*
+* Description:  Module to implement booting PCI/AGP controllers on the
+*               bus. We use the x86 real mode emulator to run the BIOS on
+*               graphics controllers to bring the cards up.
+*
+*               Note that at present this module does *not* support
+*               multiple controllers.
+*
+*               The orignal name of this file is warmboot.c.
+*               Jason ported this file to u-boot to run the ATI video card
+*               BIOS in u-boot.
+****************************************************************************/
+#include <common.h>
+
+#ifdef CONFIG_BIOSEMU
+
+#include "biosemui.h"
+#include <malloc.h>
+
+/* Length of the BIOS image */
+#define MAX_BIOSLEN         (128 * 1024L)
+
+/* Define some useful types and macros */
+#define true                1
+#define false               0
+
+/* Place to save PCI BAR's that we change and later restore */
+static u32 saveROMBaseAddress;
+static u32 saveBaseAddress10;
+static u32 saveBaseAddress14;
+static u32 saveBaseAddress18;
+static u32 saveBaseAddress20;
+
+/****************************************************************************
+PARAMETERS:
+pcidev  - PCI device info for the video card on the bus to boot
+VGAInfo - BIOS emulator VGA info structure
+
+REMARKS:
+This function executes the BIOS POST code on the controller. We assume that
+at this stage the controller has its I/O and memory space enabled and
+that all other controllers are in a disabled state.
+****************************************************************************/
+static void PCI_doBIOSPOST(pci_dev_t pcidev, BE_VGAInfo * VGAInfo)
+{
+	RMREGS regs;
+	RMSREGS sregs;
+
+	/* Determine the value to store in AX for BIOS POST. Per the PCI specs,
+	 AH must contain the bus and AL must contain the devfn, encoded as
+	 (dev << 3) | fn
+	 */
+	memset(&regs, 0, sizeof(regs));
+	memset(&sregs, 0, sizeof(sregs));
+	regs.x.ax = ((int)PCI_BUS(pcidev) << 8) |
+	    ((int)PCI_DEV(pcidev) << 3) | (int)PCI_FUNC(pcidev);
+
+	/*Setup the X86 emulator for the VGA BIOS*/
+	BE_setVGA(VGAInfo);
+
+	/*Execute the BIOS POST code*/
+	BE_callRealMode(0xC000, 0x0003, &regs, &sregs);
+
+	/*Cleanup and exit*/
+	BE_getVGA(VGAInfo);
+}
+
+/****************************************************************************
+PARAMETERS:
+pcidev  - PCI device info for the video card on the bus
+bar     - Place to return the base address register offset to use
+
+RETURNS:
+The address to use to map the secondary BIOS (AGP devices)
+
+REMARKS:
+Searches all the PCI base address registers for the device looking for a
+memory mapping that is large enough to hold our ROM BIOS. We usually end up
+finding the framebuffer mapping (usually BAR 0x10), and we use this mapping
+to map the BIOS for the device into. We use a mapping that is already
+assigned to the device to ensure the memory range will be passed through
+by any PCI->PCI or AGP->PCI bridge that may be present.
+
+NOTE: Usually this function is only used for AGP devices, but it may be
+      used for PCI devices that have already been POST'ed and the BIOS
+      ROM base address has been zero'ed out.
+
+NOTE: This function leaves the original memory aperture disabled by leaving
+      it programmed to all 1's. It must be restored to the correct value
+      later.
+****************************************************************************/
+static u32 PCI_findBIOSAddr(pci_dev_t pcidev, int *bar)
+{
+	u32 base, size;
+
+	for (*bar = 0x10; *bar <= 0x14; (*bar) += 4) {
+		pci_read_config_dword(pcidev, *bar, &base);
+		if (!(base & 0x1)) {
+			pci_write_config_dword(pcidev, *bar, 0xFFFFFFFF);
+			pci_read_config_dword(pcidev, *bar, &size);
+			size = ~(size & ~0xFF) + 1;
+			if (size >= MAX_BIOSLEN)
+				return base & ~0xFF;
+		}
+	}
+	return 0;
+}
+
+/****************************************************************************
+REMARKS:
+Some non-x86 Linux kernels map PCI relocateable I/O to values that
+are above 64K, which will not work with the BIOS image that requires
+the offset for the I/O ports to be a maximum of 16-bits. Ideally
+someone should fix the kernel to map the I/O ports for VGA compatible
+devices to a different location (or just all I/O ports since it is
+unlikely you can have enough devices in the machine to use up all
+64K of the I/O space - a total of more than 256 cards would be
+necessary).
+
+Anyway to fix this we change all I/O mapped base registers and
+chop off the top bits.
+****************************************************************************/
+static void PCI_fixupIObase(pci_dev_t pcidev, int reg, u32 * base)
+{
+	if ((*base & 0x1) && (*base > 0xFFFE)) {
+		*base &= 0xFFFF;
+		pci_write_config_dword(pcidev, reg, *base);
+
+	}
+}
+
+/****************************************************************************
+PARAMETERS:
+pcidev  - PCI device info for the video card on the bus
+
+RETURNS:
+Pointers to the mapped BIOS image
+
+REMARKS:
+Maps a pointer to the BIOS image on the graphics card on the PCI bus.
+****************************************************************************/
+void *PCI_mapBIOSImage(pci_dev_t pcidev)
+{
+	u32 BIOSImagePhys;
+	int BIOSImageBAR;
+	u8 *BIOSImage;
+
+	/*Save PCI BAR registers that might get changed*/
+	pci_read_config_dword(pcidev, PCI_ROM_ADDRESS, &saveROMBaseAddress);
+	pci_read_config_dword(pcidev, PCI_BASE_ADDRESS_0, &saveBaseAddress10);
+	pci_read_config_dword(pcidev, PCI_BASE_ADDRESS_1, &saveBaseAddress14);
+	pci_read_config_dword(pcidev, PCI_BASE_ADDRESS_2, &saveBaseAddress18);
+	pci_read_config_dword(pcidev, PCI_BASE_ADDRESS_4, &saveBaseAddress20);
+
+	/*Fix up I/O base registers to less than 64K */
+	if(saveBaseAddress14 != 0)
+		PCI_fixupIObase(pcidev, PCI_BASE_ADDRESS_1, &saveBaseAddress14);
+	else
+		PCI_fixupIObase(pcidev, PCI_BASE_ADDRESS_4, &saveBaseAddress20);
+
+	/* Some cards have problems that stop us from being able to read the
+	 BIOS image from the ROM BAR. To fix this we have to do some chipset
+	 specific programming for different cards to solve this problem.
+        */
+
+	if ((BIOSImagePhys = PCI_findBIOSAddr(pcidev, &BIOSImageBAR)) == 0) {
+		printf("Find bios addr error\n");
+		return NULL;
+	}
+
+	BIOSImage = (u8 *) BIOSImagePhys;
+
+	/*Change the PCI BAR registers to map it onto the bus.*/
+	pci_write_config_dword(pcidev, BIOSImageBAR, 0);
+	pci_write_config_dword(pcidev, PCI_ROM_ADDRESS, BIOSImagePhys | 0x1);
+
+	udelay(1);
+
+	/*Check that the BIOS image is valid. If not fail, or return the
+	 compiled in BIOS image if that option was enabled
+	 */
+	if (BIOSImage[0] != 0x55 || BIOSImage[1] != 0xAA || BIOSImage[2] == 0) {
+		return NULL;
+	}
+
+	return BIOSImage;
+}
+
+/****************************************************************************
+PARAMETERS:
+pcidev  - PCI device info for the video card on the bus
+
+REMARKS:
+Unmaps the BIOS image for the device and restores framebuffer mappings
+****************************************************************************/
+void PCI_unmapBIOSImage(pci_dev_t pcidev, void *BIOSImage)
+{
+	pci_write_config_dword(pcidev, PCI_ROM_ADDRESS, saveROMBaseAddress);
+	pci_write_config_dword(pcidev, PCI_BASE_ADDRESS_0, saveBaseAddress10);
+	pci_write_config_dword(pcidev, PCI_BASE_ADDRESS_1, saveBaseAddress14);
+	pci_write_config_dword(pcidev, PCI_BASE_ADDRESS_2, saveBaseAddress18);
+	pci_write_config_dword(pcidev, PCI_BASE_ADDRESS_4, saveBaseAddress20);
+}
+
+/****************************************************************************
+PARAMETERS:
+pcidev  - PCI device info for the video card on the bus to boot
+VGAInfo - BIOS emulator VGA info structure
+
+RETURNS:
+True if successfully initialised, false if not.
+
+REMARKS:
+Loads and POST's the display controllers BIOS, directly from the BIOS
+image we can extract over the PCI bus.
+****************************************************************************/
+static int PCI_postController(pci_dev_t pcidev, BE_VGAInfo * VGAInfo)
+{
+	u32 BIOSImageLen;
+	uchar *mappedBIOS;
+	uchar *copyOfBIOS;
+
+	/*Allocate memory to store copy of BIOS from display controller*/
+	if ((mappedBIOS = PCI_mapBIOSImage(pcidev)) == NULL) {
+		printf("videoboot: Video ROM failed to map!\n");
+		return false;
+	}
+
+	BIOSImageLen = mappedBIOS[2] * 512;
+
+	if ((copyOfBIOS = malloc(BIOSImageLen)) == NULL) {
+		printf("videoboot: Out of memory!\n");
+		return false;
+	}
+	memcpy(copyOfBIOS, mappedBIOS, BIOSImageLen);
+
+	PCI_unmapBIOSImage(pcidev, mappedBIOS);
+
+	/*Save information in VGAInfo structure*/
+	VGAInfo->function = PCI_FUNC(pcidev);
+	VGAInfo->device = PCI_DEV(pcidev);
+	VGAInfo->bus = PCI_BUS(pcidev);
+	VGAInfo->pcidev = pcidev;
+	VGAInfo->BIOSImage = copyOfBIOS;
+	VGAInfo->BIOSImageLen = BIOSImageLen;
+
+	/*Now execute the BIOS POST for the device*/
+	if (copyOfBIOS[0] != 0x55 || copyOfBIOS[1] != 0xAA) {
+		printf("videoboot: Video ROM image is invalid!\n");
+		return false;
+	}
+
+	PCI_doBIOSPOST(pcidev, VGAInfo);
+
+	/*Reset the size of the BIOS image to the final size*/
+	VGAInfo->BIOSImageLen = copyOfBIOS[2] * 512;
+	return true;
+}
+
+/****************************************************************************
+PARAMETERS:
+pcidev      - PCI device info for the video card on the bus to boot
+pVGAInfo    - Place to return VGA info structure is requested
+cleanUp     - True to clean up on exit, false to leave emulator active
+
+REMARKS:
+Boots the PCI/AGP video card on the bus using the Video ROM BIOS image
+and the X86 BIOS emulator module.
+****************************************************************************/
+int BootVideoCardBIOS(pci_dev_t pcidev, BE_VGAInfo ** pVGAInfo, int cleanUp)
+{
+	BE_VGAInfo *VGAInfo;
+
+	printf("videoboot: Booting PCI video card bus %d, function %d, device %d\n",
+	     PCI_BUS(pcidev), PCI_FUNC(pcidev), PCI_DEV(pcidev));
+
+	/*Initialise the x86 BIOS emulator*/
+	if ((VGAInfo = malloc(sizeof(*VGAInfo))) == NULL) {
+		printf("videoboot: Out of memory!\n");
+		return false;
+	}
+	memset(VGAInfo, 0, sizeof(*VGAInfo));
+	BE_init(0, 65536, VGAInfo, 0);
+
+	/*Post all the display controller BIOS'es*/
+	PCI_postController(pcidev, VGAInfo);
+
+	/*Cleanup and exit the emulator if requested. If the BIOS emulator
+	is needed after booting the card, we will not call BE_exit and
+	leave it enabled for further use (ie: VESA driver etc).
+	*/
+	if (cleanUp) {
+		BE_exit();
+		if (VGAInfo->BIOSImage)
+			free(VGAInfo->BIOSImage);
+		free(VGAInfo);
+		VGAInfo = NULL;
+	}
+	/*Return VGA info pointer if the caller requested it*/
+	if (pVGAInfo)
+		*pVGAInfo = VGAInfo;
+	return true;
+}
+
+#endif