mirror of
https://github.com/wiidev/usbloadergx.git
synced 2024-09-08 08:33:19 +02:00
199 lines
5.2 KiB
C++
199 lines
5.2 KiB
C++
![]() |
#include <string.h>
|
||
|
#include "ramdisc.h"
|
||
|
|
||
|
static inline u16 u8array_to_u16 (const u8* item, int offset)
|
||
|
{
|
||
|
return ( item[offset] | (item[offset + 1] << 8));
|
||
|
}
|
||
|
static inline u32 u8array_to_u32 (const u8* item, int offset)
|
||
|
{
|
||
|
return ( item[offset] | (item[offset + 1] << 8) | (item[offset + 2] << 16) | (item[offset + 3] << 24) );
|
||
|
}
|
||
|
static inline void u16_to_u8array (u8* item, int offset, u16 value)
|
||
|
{
|
||
|
item[offset] = (u8) value; item[offset + 1] = (u8)(value >> 8);
|
||
|
}
|
||
|
static inline void u32_to_u8array (u8* item, int offset, u32 value)
|
||
|
{
|
||
|
item[offset] = (u8) value;
|
||
|
item[offset + 1] = (u8)(value >> 8);
|
||
|
item[offset + 2] = (u8)(value >> 16);
|
||
|
item[offset + 3] = (u8)(value >> 24);
|
||
|
}
|
||
|
|
||
|
|
||
|
class padding
|
||
|
{
|
||
|
public:
|
||
|
padding(u32 Start, u32 NumSectors)
|
||
|
{
|
||
|
start = Start;
|
||
|
end = Start + NumSectors;
|
||
|
data = new u8[NumSectors*512];
|
||
|
next = 0;
|
||
|
}
|
||
|
~padding() { delete [] data;}
|
||
|
|
||
|
u32 start;
|
||
|
u32 end;
|
||
|
u8 *data;
|
||
|
padding *next;
|
||
|
};
|
||
|
|
||
|
static u32 __ramdisk_sectorsOfPadding;
|
||
|
static padding *__ramdisk_data_start;
|
||
|
static padding *__ramdisk_data_end;
|
||
|
|
||
|
static bool __ramdisk_IsInserted(void)
|
||
|
{
|
||
|
return __ramdisk_data_start!=NULL;
|
||
|
}
|
||
|
//forward decleration
|
||
|
static bool __ramdisk_WriteSectors(size_t Sector, size_t numSectors, u8 *Buffer);
|
||
|
|
||
|
bool initRAMDisc(u32 Size, u32 Padding)
|
||
|
{
|
||
|
if(__ramdisk_data_start) return true; // is init
|
||
|
|
||
|
if(Size > 16*1024*1024) Size = 16*1024*1024; // maximum 16 MB
|
||
|
if(Size < 16*1024) Size = 16*1024; // minimum 16 MB
|
||
|
if(Padding > Size) Padding = Size; // Padding maximum =Disksize
|
||
|
if(Padding < 4*1024) Padding = 4*1024; // Padding minimum 4kB
|
||
|
|
||
|
__ramdisk_sectorsOfPadding = Padding/512;
|
||
|
|
||
|
__ramdisk_data_start = __ramdisk_data_end = new padding(0, __ramdisk_sectorsOfPadding);
|
||
|
if(!__ramdisk_data_start) return false;
|
||
|
|
||
|
// FAT12 Formatieren
|
||
|
u8 sector[512] = {0, };
|
||
|
sector[0x00d] = 2; /*BPB_sectorsPerCluster*/
|
||
|
sector[0x00e] = 1; /*BPB_reservedSectors*/
|
||
|
sector[0x010] = 1; /*BPB_numFATs*/
|
||
|
u16_to_u8array (sector, 0x011, 48); /*BPB_rootEntries*/
|
||
|
int num_sectors = Size/512;
|
||
|
u16_to_u8array (sector, 0x013, num_sectors); /*BPB_numSectorsSmall*/
|
||
|
int num_clusters = (num_sectors-1-3) /2;
|
||
|
int sectors_per_fat = (num_clusters * 3 + 1023) /1024;
|
||
|
u16_to_u8array (sector, 0x016, sectors_per_fat); /*BPB_sectorsPerFAT*/
|
||
|
//u32_to_u8array (sector, 0x020, Size/512); /*BPB_numSectors*/
|
||
|
sector[0x036] = 'F';
|
||
|
sector[0x037] = 'A';
|
||
|
sector[0x038] = 'T';
|
||
|
sector[0x1fe] = 0x55;
|
||
|
sector[0x1ff] = 0xaa;
|
||
|
if(!__ramdisk_WriteSectors(0, 1, sector))
|
||
|
goto error;
|
||
|
memset(sector, 0, 512);
|
||
|
// clear FAT & rootDir
|
||
|
for(int i=1; i<= sectors_per_fat+3/*sectors_per_rootDir*/; i++)
|
||
|
if(!__ramdisk_WriteSectors(1, 1, sector))
|
||
|
goto error;
|
||
|
return true;
|
||
|
error:
|
||
|
delete __ramdisk_data_start;
|
||
|
__ramdisk_data_start = 0;
|
||
|
return false;
|
||
|
|
||
|
}
|
||
|
|
||
|
void exitRAMDisc()
|
||
|
{
|
||
|
while(__ramdisk_data_start)
|
||
|
{
|
||
|
padding *tmp = __ramdisk_data_start;
|
||
|
__ramdisk_data_start = __ramdisk_data_start->next;
|
||
|
delete tmp;
|
||
|
}
|
||
|
}
|
||
|
static u8 *__ramdisk_findSector(size_t Sector, size_t *Sectors)
|
||
|
{
|
||
|
if(__ramdisk_data_start==NULL) return NULL;
|
||
|
for(padding *tmp = __ramdisk_data_start; tmp; tmp=tmp->next)
|
||
|
{
|
||
|
if(tmp->start <= Sector && tmp->end >= Sector)
|
||
|
{
|
||
|
if(Sectors) *Sectors = 1+tmp->end-Sector;
|
||
|
return &(tmp->data[(Sector-tmp->start)*512]);
|
||
|
}
|
||
|
}
|
||
|
// not found -> add padding
|
||
|
__ramdisk_data_end->next = new padding((Sector/__ramdisk_sectorsOfPadding)*__ramdisk_sectorsOfPadding, __ramdisk_sectorsOfPadding);
|
||
|
if(__ramdisk_data_end->next)
|
||
|
{
|
||
|
__ramdisk_data_end = __ramdisk_data_end->next;
|
||
|
return &( __ramdisk_data_end->data[(Sector-__ramdisk_data_end->start)*512]);
|
||
|
}
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static bool __ImplizitInit = false;
|
||
|
static bool __ramdisk_Startup(void)
|
||
|
{
|
||
|
if(!__ramdisk_IsInserted())
|
||
|
{
|
||
|
// Std=8MB/64kB Padding
|
||
|
return (__ImplizitInit = initRAMDisc(8*1024*1024, 64 * 1024));
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
static bool __ramdisk_ReadSectors(size_t Sector, size_t numSectors, u8 *Buffer)
|
||
|
{
|
||
|
size_t num_sectors;
|
||
|
while(numSectors)
|
||
|
{
|
||
|
if(u8 *buff = __ramdisk_findSector(Sector,&num_sectors))
|
||
|
{
|
||
|
if(num_sectors > numSectors) num_sectors = numSectors;
|
||
|
memcpy(Buffer, buff, num_sectors * 512);
|
||
|
numSectors -= num_sectors;
|
||
|
Buffer+= num_sectors;
|
||
|
}
|
||
|
else
|
||
|
return false;
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
static bool __ramdisk_WriteSectors(size_t Sector, size_t numSectors, u8 *Buffer)
|
||
|
{
|
||
|
size_t num_sectors;
|
||
|
while(numSectors)
|
||
|
{
|
||
|
if(u8 *buff = __ramdisk_findSector(Sector,&num_sectors))
|
||
|
{
|
||
|
if(num_sectors > numSectors) num_sectors = numSectors;
|
||
|
memcpy(buff, Buffer, num_sectors * 512);
|
||
|
numSectors -= num_sectors;
|
||
|
Buffer+= num_sectors;
|
||
|
}
|
||
|
else
|
||
|
return false;
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
static bool __ramdisk_ClearStatus(void)
|
||
|
{
|
||
|
return true;
|
||
|
}
|
||
|
static bool __ramdisk_Shutdown(void)
|
||
|
{
|
||
|
if(__ImplizitInit)
|
||
|
{
|
||
|
__ImplizitInit = false;
|
||
|
exitRAMDisc();
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
const DISC_INTERFACE __io_ramdisk = {
|
||
|
DEVICE_TYPE_RAM_DISK,
|
||
|
FEATURE_MEDIUM_CANREAD | FEATURE_MEDIUM_CANWRITE | 0x1000,
|
||
|
(FN_MEDIUM_STARTUP)&__ramdisk_Startup,
|
||
|
(FN_MEDIUM_ISINSERTED)&__ramdisk_IsInserted,
|
||
|
(FN_MEDIUM_READSECTORS)&__ramdisk_ReadSectors,
|
||
|
(FN_MEDIUM_WRITESECTORS)&__ramdisk_WriteSectors,
|
||
|
(FN_MEDIUM_CLEARSTATUS)&__ramdisk_ClearStatus,
|
||
|
(FN_MEDIUM_SHUTDOWN)&__ramdisk_Shutdown
|
||
|
};
|