/***************************************************************************
*             __________               __   ___.
*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
*                     \/            \/     \/    \/            \/
* $Id$
*
* Plugin for reprogramming only the second Rockbox image.
*
* Copyright (C) 2003 Jörg Hohensohn [IDC]Dragon
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "plugin.h"

#ifndef UINT8
#define UINT8 unsigned char
#endif

#ifndef UINT16
#define UINT16 unsigned short
#endif

#ifndef UINT32
#define UINT32 unsigned long
#endif

// hard-coded values
static volatile UINT8* FB = (UINT8*)0x02000000; // Flash base address
#define SECTORSIZE 4096 // size of one flash sector

#define ROCKBOX_DEST 0x09000000
#define ROCKBOX_EXEC 0x09000200
#define FILENAME "/rockbox.ucl"
#define VERS_ADR 0xFE // position of firmware version value in Flash
#define UCL_HEADER 26 // size of the header generated by uclpack

typedef struct 
{
	UINT32 destination; // address to copy it to
	UINT32 size;          // how many bytes of payload (to the next header)
	UINT32 execute;      // entry point
	UINT32 flags;         // uncompressed or compressed
	// end of header, now comes the payload
} tImageHeader;


// result of the CheckFirmwareFile() function
typedef enum
{
	eOK = 0,
	eFileNotFound, // errors from here on
	eTooBig,
	eTooSmall,
	eReadErr,
	eNotUCL,
	eWrongAlgorithm,
	eMultiBlocks,
} tCheckResult;

typedef struct 
{
	UINT8 manufacturer;
	UINT8 id;
	int size;
	char name[32];
} tFlashInfo;

static struct plugin_api* rb; // here is a global api struct pointer

#define SEC_SIZE 4096 // size of one flash sector
static UINT8 sector[SEC_SIZE]; // better not place this on the stack...


/***************** Flash Functions *****************/


// read the manufacturer and device ID
bool ReadID(volatile UINT8* pBase, UINT8* pManufacturerID, UINT8* pDeviceID)
{
	UINT8 not_manu, not_id; // read values before switching to ID mode
	UINT8 manu, id; // read values when in ID mode
	
	pBase = (UINT8*)((UINT32)pBase & 0xFFF80000); // round down to 512k align, to make shure
	
	not_manu = pBase[0]; // read the normal content
	not_id   = pBase[1]; // should be 'A' (0x41) and 'R' (0x52) from the "ARCH" marker
	
	pBase[0x5555] = 0xAA; // enter command mode
	pBase[0x2AAA] = 0x55;
	pBase[0x5555] = 0x90; // ID command
	rb->sleep(HZ/50); // Atmel wants 20ms pause here
	
	manu = pBase[0];
	id   = pBase[1];
	
	pBase[0] = 0xF0; // reset flash (back to normal read mode)
	rb->sleep(HZ/50); // Atmel wants 20ms pause here
	
	/* I assume success if the obtained values are different from
	the normal flash content. This is not perfectly bulletproof, they 
	could theoretically be the same by chance, causing us to fail. */
	if (not_manu != manu || not_id != id) // a value has changed
	{
		*pManufacturerID = manu; // return the results
		*pDeviceID = id;
		return true; // success
	}
	return false; // fail
}


// eraze the sector which contains the given address
bool ErazeSector(volatile UINT8* pAddr)
{
	volatile UINT8* pBase = (UINT8*)((UINT32)pAddr & 0xFFF80000); // round down to 512k align
	unsigned timeout = 43000; // the timeout loop should be no less than 25ms
	
	pBase[0x5555] = 0xAA; // enter command mode
	pBase[0x2AAA] = 0x55;
	pBase[0x5555] = 0x80; // eraze command
	pBase[0x5555] = 0xAA; // enter command mode
	pBase[0x2AAA] = 0x55;
	*pAddr = 0x30; // eraze the sector

	// I counted 7 instructions for this loop -> min. 0.58 us per round
	// Plus memory waitstates it will be much more, gives margin
	while (*pAddr != 0xFF && --timeout); // poll for erazed

	return (timeout != 0);
}

// address must be in an erazed location
inline bool ProgramByte(volatile UINT8* pAddr, UINT8 data)
{
	unsigned timeout = 35; // the timeout loop should be no less than 20us
	
	if (~*pAddr & data) // just a safety feature, not really necessary
		return false; // can't set any bit from 0 to 1
	
	FB[0x5555] = 0xAA; // enter command mode
	FB[0x2AAA] = 0x55;
	FB[0x5555] = 0xA0; // byte program command
	
	*pAddr = data;
	
	// I counted 7 instructions for this loop -> min. 0.58 us per round
	// Plus memory waitstates it will be much more, gives margin
	while (*pAddr != data && --timeout); // poll for programmed
	
	return (timeout != 0);
}

// this returns true if supported and fills the info struct
bool GetFlashInfo(tFlashInfo* pInfo)
{
	rb->memset(pInfo, 0, sizeof(tFlashInfo));
	
	if (!ReadID(FB, &pInfo->manufacturer, &pInfo->id))
		return false;
	
	if (pInfo->manufacturer == 0xBF) // SST
	{
		if (pInfo->id == 0xD6)
		{
			pInfo->size = 256* 1024; // 256k
			rb->strcpy(pInfo->name, "SST39VF020");
			return true;
		}
		else if (pInfo->id == 0xD7)
		{
			pInfo->size = 512* 1024; // 512k
			rb->strcpy(pInfo->name, "SST39VF040");
			return true;
		}
		else
			return false;
	}
	return false;
}


/*********** Tool Functions ************/

// place a 32 bit value into memory, big endian
void Write32(UINT8* pByte, UINT32 value)
{
	pByte[0] = (UINT8)(value >> 24);	
	pByte[1] = (UINT8)(value >> 16);	
	pByte[2] = (UINT8)(value >> 8);	
	pByte[3] = (UINT8)(value);	
}

// read a 32 bit value from memory, big endian
UINT32 Read32(UINT8* pByte)
{
	UINT32 value = 0;

	value |= (UINT32)pByte[0] << 24;
	value |= (UINT32)pByte[1] << 16;
	value |= (UINT32)pByte[2] << 8;
	value |= (UINT32)pByte[3];

	return value;
}


// get the start address of the second image
tImageHeader* GetSecondImage(void)
{
	tImageHeader* pImage1;
	UINT32 pos = 0;	// dafault: not found
	UINT32* pFlash = (UINT32*)FB;

	UINT16 version = *(UINT16*)(FB + VERS_ADR);
	if (version < 200) // at least 2.00
	{
		return 0; // not our flash layout
	}

	// determine the first image position
	pos = pFlash[2] + pFlash[3]; // position + size of the bootloader = after it
	pos = (pos + 3) & ~3; // be shure it's 32 bit aligned
	pImage1 = (tImageHeader*)pos;

	if (pImage1->destination != ROCKBOX_DEST || pImage1->execute != ROCKBOX_EXEC)
		return 0; // seems to be no Rockbox stuff in here

	if (pImage1->size != 0)
	{	// success, we have a second image
		pos = (UINT32)pImage1 + sizeof(tImageHeader) + pImage1->size;
		if (((pos + SECTORSIZE-1) & ~(SECTORSIZE-1)) != pos)
		{	// not sector-aligned
			pos = 0; // sanity check failed
		}
	}

	return (tImageHeader*)pos;
}


/*********** Image File Functions ************/

// so far, only compressed images in UCL NRV algorithm 2e supported
tCheckResult CheckImageFile(char* filename, int space, tImageHeader* pHeader)
{
	int i;
	int fd;
	int filesize; // size info

	int fileread = 0; // total size as read from the file
	int read; // how many for this sector
	
	// magic file header for compressed files
	static const UINT8 magic[8] = { 0x00,0xe9,0x55,0x43,0x4c,0xff,0x01,0x1a };
	UINT8 ucl_header[UCL_HEADER];

	fd = rb->open(filename, O_RDONLY);
	if (fd < 0)
		return eFileNotFound;
	
	filesize = rb->filesize(fd);
	if (filesize - (int)sizeof(ucl_header) - 8 > space)
	{
		rb->close(fd);
		return eTooBig;
	}
	else if (filesize < 50000) // give it some reasonable lower limit
	{
		rb->close(fd);
		return eTooSmall;
	}
	
	// do some sanity checks
	
	read = rb->read(fd, ucl_header, sizeof(ucl_header));
	fileread += read;
	if (read != sizeof(ucl_header))
	{
		rb->close(fd);
		return eReadErr;
	}
	
	// compare the magic header
	for (i=0; i<8; i++)
	{
		if (ucl_header[i] != magic[i])
		{
			rb->close(fd);
			return eNotUCL;
		}
	}
	
	// check for supported algorithm
	if (ucl_header[12] != 0x2E)
	{
		rb->close(fd);
		return eWrongAlgorithm;
	}

	pHeader->size = Read32(ucl_header + 22); // compressed size
	if (pHeader->size != filesize - sizeof(ucl_header) - 8)
	{
		rb->close(fd);
		return eMultiBlocks;
	}
	
	if (Read32(ucl_header + 18) > pHeader->size) // compare with uncompressed size
	{	// normal case
		pHeader->flags = 0x00000001; // flags for UCL compressed
	}
	else
	{
		pHeader->flags = 0x00000000; // very unlikely, content was not compressible
	}
	
	// check if we can read the whole file
	do
	{
		read = rb->read(fd, sector, SEC_SIZE);
		fileread += read;
	} while (read == SEC_SIZE);
	
	rb->close(fd);
	
	if (fileread != filesize)
		return eReadErr;
	
	// fill in the hardcoded rest of the header
	pHeader->destination = ROCKBOX_DEST;
	pHeader->execute = ROCKBOX_EXEC;
	
	return eOK;
}


// returns the # of failures, 0 on success
unsigned ProgramImageFile(char* filename, UINT8* pos, tImageHeader* pImageHeader, int start, int size)
{
	int i;
	int fd;
	int read; // how many for this sector
	unsigned failures = 0;
	
	fd = rb->open(filename, O_RDONLY);
	if (fd < 0)
		return false;

	// no error checking necessary here, we checked for minimum size already
	rb->lseek(fd, start, SEEK_SET); // go to start position
	
	*(tImageHeader*)sector = *pImageHeader; // copy header into sector buffer
	read = rb->read(fd, sector + sizeof(tImageHeader), SEC_SIZE - sizeof(tImageHeader)); // payload behind
	size -= read;
	read += sizeof(tImageHeader); // to be programmed, but not part of the file

	do
	{
		if (!ErazeSector(pos))
		{
			// nothing we can do, let the programming count the errors
		}
		
		for (i=0; i<read; i++)
		{
			if (!ProgramByte(pos + i, sector[i]))
			{
				failures++;
			}
		}

		pos += SEC_SIZE;
		read = rb->read(fd, sector, (size > SEC_SIZE) ? SEC_SIZE : size); // payload for next sector
		size -= read;
	} while (read > 0);
	
	rb->close(fd);
	
	return failures;
}

// returns the # of failures, 0 on success
unsigned VerifyImageFile(char* filename, UINT8* pos, tImageHeader* pImageHeader, int start, int size)
{
	int i;
	int fd;
	int read; // how many for this sector
	unsigned failures = 0;
	
	fd = rb->open(filename, O_RDONLY);
	if (fd < 0)
		return false;

	// no error checking necessary here, we checked for minimum size already
	rb->lseek(fd, start, SEEK_SET); // go to start position
	
	*(tImageHeader*)sector = *pImageHeader; // copy header into sector buffer
	read = rb->read(fd, sector + sizeof(tImageHeader), SEC_SIZE - sizeof(tImageHeader)); // payload behind
	size -= read;
	read += sizeof(tImageHeader); // to be programmed, but not part of the file

	do
	{
		for (i=0; i<read; i++)
		{
			if (pos[i] != sector[i])
			{
				failures++;
			}
		}

		pos += SEC_SIZE;
		read = rb->read(fd, sector, (size > SEC_SIZE) ? SEC_SIZE : size); // payload for next sector
		size -= read;
	} while (read);
	
	rb->close(fd);
	
	return failures;
}


/***************** User Interface Functions *****************/
/*                 (to be changed for Player)               */

#ifdef HAVE_LCD_BITMAP

// helper for DoUserDialog()
void ShowFlashInfo(tFlashInfo* pInfo, tImageHeader* pImageHeader)
{
	char buf[32];
	
	if (!pInfo->manufacturer)
	{
		rb->lcd_puts(0, 0, "Flash: M=?? D=??");
	}
	else
	{
		if (pInfo->size)
		{
			rb->snprintf(buf, sizeof(buf), "Flash size: %d KB", pInfo->size / 1024);
			rb->lcd_puts(0, 0, buf);
		}
		else
		{
			rb->lcd_puts(0, 0, "Unsupported chip");
		}
		
	}

	if (pImageHeader)
	{
		rb->snprintf(buf, sizeof(buf), "Image at %d KB", ((UINT8*)pImageHeader - FB) / 1024);
		rb->lcd_puts(0, 1, buf);
	}
	else
	{
		rb->lcd_puts(0, 1, "No image found!");
	}
	
	rb->lcd_update();
}


// Kind of our main function, defines the application flow.
void DoUserDialog(void)
{
	tImageHeader ImageHeader;
	tFlashInfo FlashInfo;
	char buf[32];
	int button;
	int rc; // generic return code
	UINT32 space, aligned_size, true_size;
	UINT8* pos;

	rb->lcd_setfont(FONT_SYSFIXED);
	
	pos = (void*)GetSecondImage();
	rc = GetFlashInfo(&FlashInfo);

	ShowFlashInfo(&FlashInfo, (void*)pos);
	if (FlashInfo.size == 0) // no valid chip
	{
		rb->splash(HZ*3, 0, true, "Not flashable");
		return; // exit
	}
	else if (pos == 0)
	{
		rb->splash(HZ*3, 0, true, "No Image");
		return; // exit
	}

	rb->lcd_puts(0, 3, "using file:");
	rb->lcd_puts(0, 4, FILENAME);
	rb->lcd_puts(0, 6, "[F1] to check file");
	rb->lcd_puts(0, 7, "other key to exit");
	rb->lcd_update();
	
	button = rb->button_get(true);
	button = rb->button_get(true);
	
	if (button != BUTTON_F1)
	{
		return;
	}
	
	rb->lcd_clear_display();
	rb->lcd_puts(0, 0, "checking...");
	rb->lcd_update();
	
	space = FlashInfo.size - (pos-FB + sizeof(ImageHeader)); // size minus start
	rc = CheckImageFile(FILENAME, space, &ImageHeader);
	rb->lcd_puts(0, 0, "checked:");
	switch (rc)
	{
	case eOK:
		rb->lcd_puts(0, 1, "File OK.");
		break;
	case eNotUCL:
		rb->lcd_puts(0, 1, "File not UCL ");
		rb->lcd_puts(0, 2, "compressed.");
		rb->lcd_puts(0, 3, "Use uclpack --2e");
		rb->lcd_puts(0, 4, " --10 rockbox.bin");
		break;
	case eWrongAlgorithm:
		rb->lcd_puts(0, 1, "Wrong algorithm");
		rb->lcd_puts(0, 2, "for compression.");
		rb->lcd_puts(0, 3, "Use uclpack --2e");
		rb->lcd_puts(0, 4, " --10 rockbox.bin");
		break;
	case eFileNotFound:
		rb->lcd_puts(0, 1, "File not found.");
		rb->lcd_puts(0, 2, "Put this in root:");
		rb->lcd_puts(0, 4, FILENAME);
		break;
	case eTooBig:
		rb->lcd_puts(0, 1, "File too big,");
		rb->lcd_puts(0, 2, "won't fit in chip.");
		break;
	case eTooSmall:
		rb->lcd_puts(0, 1, "File too small.");
		rb->lcd_puts(0, 2, "Incomplete?");
		break;
	case eReadErr:
		rb->lcd_puts(0, 1, "File read error.");
		break;
	case eMultiBlocks:
		rb->lcd_puts(0, 1, "File invalid.");
		rb->lcd_puts(0, 2, "Blocksize");
		rb->lcd_puts(0, 3, " too small?");
		break;
	default:
		rb->lcd_puts(0, 1, "Check failed.");
		break;
	}
	
	if (rc == eOK)
	{	// was OK
		rb->lcd_puts(0, 6, "[F2] to program");
		rb->lcd_puts(0, 7, "other key to exit");
	}
	else
	{	// error occured
		rb->lcd_puts(0, 6, "Any key to exit");
	}
	
	rb->lcd_update();
	
	button = rb->button_get(true);
	button = rb->button_get(true);
	
	if (button != BUTTON_F2)
	{
		return;
	}
	
	true_size = ImageHeader.size;
	aligned_size = ((sizeof(tImageHeader) + true_size + SECTORSIZE-1) & ~(SECTORSIZE-1)) - sizeof(tImageHeader); // round up to next flash sector
	ImageHeader.size = aligned_size; // increase image size such that we reach the next sector

	rb->lcd_clear_display();
	rb->lcd_puts(0, 0, "Programming...");
	rb->lcd_update();
	
	rc = ProgramImageFile(FILENAME, pos, &ImageHeader, UCL_HEADER, true_size);
	if (rc)
	{   // errors
		rb->lcd_clear_display();
		rb->lcd_puts(0, 0, "Error:");
		rb->lcd_puts(0, 1, "Programming fail!");
		rb->snprintf(buf, sizeof(buf), "%d errors", rc);
		rb->lcd_puts(0, 2, buf);
		rb->lcd_update();
		button = rb->button_get(true);
		button = rb->button_get(true);
	}
	
	rb->lcd_clear_display();
	rb->lcd_puts(0, 0, "Verifying...");
	rb->lcd_update();
	
	rc = VerifyImageFile(FILENAME, pos, &ImageHeader, UCL_HEADER, true_size);
	
	rb->lcd_clear_display();
	if (rc == 0)
	{
		rb->lcd_puts(0, 0, "Verify OK.");
	}
	else
	{
		rb->lcd_puts(0, 0, "Error:");
		rb->lcd_puts(0, 1, "Verify fail!");
		rb->snprintf(buf, sizeof(buf), "%d errors", rc);
		rb->lcd_puts(0, 2, buf);
		rb->lcd_puts(0, 3, "Use safe image");
		rb->lcd_puts(0, 4, "if booting hangs:");
		rb->lcd_puts(0, 5, "F1 during power-on");
	}
	rb->lcd_puts(0, 7, "Any key to exit");
	rb->lcd_update();
	
	button = rb->button_get(true);
	button = rb->button_get(true);
}

#else // HAVE_LCD_BITMAP

// Player implementation has to go here
void DoUserDialog(void)
{
}

#endif // HAVE_LCD_BITMAP


/***************** Plugin Entry Point *****************/

enum plugin_status plugin_start(struct plugin_api* api, void* parameter)
{
	
	
	/* this macro should be called as the first thing you do in the plugin.
	it test that the api version and model the plugin was compiled for
	matches the machine it is running on */
	TEST_PLUGIN_API(api);
	
	/* if you don't use the parameter, you can do like
	this to avoid the compiler warning about it */
	(void)parameter;
	
	rb = api; /* copy to global api pointer */
	
	/* now go ahead and have fun! */
	DoUserDialog();

	return PLUGIN_OK;
}