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Correctly format a ControllerPak #481

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merged 4 commits into from
Jan 22, 2024
Merged

Correctly format a ControllerPak #481

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1f233f4
Add format cpak fix
networkfusion Jan 11, 2024
883b887
Remove binary blob
networkfusion Jan 19, 2024
0b3d8ea
Use real random number
networkfusion Jan 19, 2024
95b508e
Use entropy for setting the ID
networkfusion Jan 22, 2024
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129 changes: 66 additions & 63 deletions src/mempak.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
#include <string.h>
#include "libdragon.h"
#include "regsinternal.h"
#include <unistd.h>

/**
* @defgroup mempak Mempak Filesystem Routines
Expand Down Expand Up @@ -839,86 +840,88 @@ int get_mempak_free_space( int controller )
}

/**
* @brief Format a mempak
* @brief Format a ControllerPak (mempak)
*
* Formats a mempak. Should only be done to wipe a mempak or to initialize
* the filesystem in case of a blank or corrupt mempak.
* Formats a ControllerPak (mempak). This should only be done to totally wipe and re-initialize
* the filesystem in case of a blank or corrupt Pak after a repair has failed.
*
* @param[in] controller
* The controller (0-3) to format the mempak on
* The Controller (0-3) that the CPak is inserted.
*
* @retval 0 if the mempak was formatted successfully
* @retval -2 if the mempak was not present or couldn't be formatted
* @retval 0 if the CPak was formatted successfully.
* @retval -2 if the CPak was not present or couldn't be formatted.
*/
int format_mempak( int controller )
{
/* Many mempak dumps exist online for users of emulated games to get
saves that have all unlocks. Every beginning sector on all these
was the same, so this is the data I use to initialize the first
sector */
uint8_t sector[MEMPAK_BLOCK_SIZE] = { 0x81,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
0xff,0xff,0xff,0xff,0x05,0x1a,0x5f,0x13,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0x01,0xff,0x66,0x25,0x99,0xcd,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0x05,0x1a,0x5f,0x13,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0x01,0xff,0x66,0x25,0x99,0xcd,
0xff,0xff,0xff,0xff,0x05,0x1a,0x5f,0x13,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0x01,0xff,0x66,0x25,0x99,0xcd,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0x05,0x1a,0x5f,0x13,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0x01,0xff,0x66,0x25,0x99,0xcd,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };

if( write_mempak_sector( controller, 0, sector ) )
{
/* Couldn't write initial sector */
return -2;
/* set the size to 1280 as the notes table (768-1280) will need to be initialized. */
uint8_t cpak_header_data[1280] = {0x00};

uint16_t i, word, sum1 = 0, sum2 = 0;

/* 0x00 24 Serial number
* 0x18 1 unused (always 0)
* 0x19 1 Device ID (always 1)
* 0x1A 1 Bank size (always 1)
* 0x1B 1 unused (always 0)
* 0x1C 2 Checksum 1
* 0x1E 2 Checksum 2 */
static uint8_t cpakid_array[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x00 - 0x07 (0 - 7) */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x08 - 0x0f (8 - 15) */
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x10 - 0x1f (16 - 23) */
0x00, 0x01, 0x01, 0x00, 0x01, 0x01, 0xFE, 0xF1 /* 0x20 - 0x2f (24 - 32) */
};

/* Assign 'random' value to ID */
getentropy(&cpakid_array, 24); /* Use system entropy to write the first 24 bytes */

/* Create checksum */
for (i = 0; i < 28; i += 2)
{
word = (cpakid_array[i] << 8) + cpakid_array[i + 1];
sum1 += word; sum2 += ~word;
}

/* Write out entry sectors, which can safely be zero */
memset( sector, 0x0, MEMPAK_BLOCK_SIZE );
if( write_mempak_sector( controller, 3, sector ) ||
write_mempak_sector( controller, 4, sector ) )
/* Update checksum */
cpakid_array[0x1c] = sum1 >> 8;
cpakid_array[0x1d] = sum1 & 0xFF;
cpakid_array[0x1e] = sum2 >> 8;
cpakid_array[0x1f] = sum2 & 0xFF;

/* Update ID blocks with IDs */
for(i = 0; i < 32; i++)
{
/* Couldn't write entry sectors */
return -2;
/* ID Block (Primary) */
cpak_header_data[0x20 + i] = cpakid_array[i];
/* 0x40 is unused */
/* ID Block (Backup 1) */
cpak_header_data[0x60 + i] = cpakid_array[i];
/* ID Block (Backup 2) */
cpak_header_data[0x80 + i] = cpakid_array[i];
/* 0xA0 is unused */
/* ID Block (Backup 3) */
cpak_header_data[0xC0 + i] = cpakid_array[i];
/* 0xE0 is unused */
}

/* Go through, insert 'empty sector' marking on all entries */
for( int i = 0; i < 128; i++ )
/* initilize Index Table and backup (plus checksums) */
for(i = 5; i < 128; i++)
{
sector[(i << 1) + 1] = BLOCK_EMPTY;
cpak_header_data[256 + (i * 2) + 1] = 3;
cpak_header_data[512 + (i * 2) + 1] = 3;
}

/* Fix the checksum */
sector[1] = __get_toc_checksum( sector );
cpak_header_data[257] = 0x71;
cpak_header_data[513] = 0x71;

/* Write out */
if( write_mempak_sector( controller, 1, sector ) ||
write_mempak_sector( controller, 2, sector ) )
/* Write each sector */
for (i = 0; i < 1280; i += 256)
{
/* Couldn't write TOC sectors */
return -2;
if(write_mempak_sector(controller, i / 256, &cpak_header_data[i]))
{
/* Couldn't write sector */
return -2;
}
}

return 0;
Expand Down