Intento emitir un scsi read(10) y write(10) en una SSD. Yo uso this example code como referencia/código básico.Lectura SCSI (10) y escritura (10) con la interfaz genérica SCSI
Ésta es mis SCSI leen:
#define READ_REPLY_LEN 32
#define READ_CMDLEN 10
void scsi_read()
{
unsigned char Readbuffer[ SCSI_OFF + READ_REPLY_LEN ];
unsigned char cmdblk [ READ_CMDLEN ] =
{ 0x28, /* command */
0, /* lun/reserved */
0, /* lba */
0, /* lba */
0, /* lba */
0, /* lba */
0, /* reserved */
0, /* transfer length */
READ_REPLY_LEN, /* transfer length */
0 };/* reserved/flag/link */
memset(Readbuffer,0,sizeof(Readbuffer));
memcpy(cmd + SCSI_OFF, cmdblk, sizeof(cmdblk));
/*
* +------------------+
* | struct sg_header | <- cmd
* +------------------+
* | copy of cmdblk | <- cmd + SCSI_OFF
* +------------------+
*/
if (handle_scsi_cmd(sizeof(cmdblk), 0, cmd,
sizeof(Readbuffer) - SCSI_OFF, Readbuffer)) {
fprintf(stderr, "read failed\n");
exit(2);
}
hex_dump(Readbuffer,sizeof(Readbuffer));
}
y este es mi SCSI de escritura:
void scsi_write (void)
{
unsigned char Writebuffer[SCSI_OFF];
unsigned char cmdblk [] =
{ 0x2A, /* 0: command */
0, /* 1: lun/reserved */
0, /* 2: LBA */
0, /* 3: LBA */
0, /* 4: LBA */
0, /* 5: LBA */
0, /* 6: reserved */
0, /* 7: transfer length */
0, /* 8: transfer length */
0 };/* 9: control */
memset(Writebuffer,0,sizeof(Writebuffer));
memcpy(cmd + SCSI_OFF, cmdblk, sizeof(cmdblk));
cmd[SCSI_OFF+sizeof(cmdblk)+0] = 'A';
cmd[SCSI_OFF+sizeof(cmdblk)+1] = 'b';
cmd[SCSI_OFF+sizeof(cmdblk)+2] = 'c';
cmd[SCSI_OFF+sizeof(cmdblk)+3] = 'd';
cmd[SCSI_OFF+sizeof(cmdblk)+4] = 'e';
cmd[SCSI_OFF+sizeof(cmdblk)+5] = 'f';
cmd[SCSI_OFF+sizeof(cmdblk)+6] = 'g';
cmd[SCSI_OFF+sizeof(cmdblk)+7] = 0;
/*
* +------------------+
* | struct sg_header | <- cmd
* +------------------+
* | copy of cmdblk | <- cmd + SCSI_OFF
* +------------------+
* | data to write |
* +------------------+
*/
if (handle_scsi_cmd(sizeof(cmdblk), 8, cmd,
sizeof(Writebuffer) - SCSI_OFF, Writebuffer)) {
fprintf(stderr, "write failed\n");
exit(2);
}
}
En el siguiente ejemplo que hago
- SCSI leen
- SCSI escriben
- SCSI leen
Y imprimen los hexdumps de los datos que se escribe (SCSI escritura) y lo que se lee (SCSI leen)
Read(10)
[0000] 00 00 00 44 00 00 00 44 00 00 00 00 00 00 00 00 ...D...D ........
[0010] 00 2C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........
[0020] 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........
[0030] 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........
[0040] 00 00 00 00 ....
Write(10):
[0000] 00 00 00 00 00 00 00 24 00 00 00 00 00 00 00 00 ........ ........
[0010] 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........
[0020] 00 00 00 00 2A 00 00 00 00 00 00 00 00 00 41 62 ........ ......Ab
[0030] 63 64 65 66 67 00 cdefg.
Read(10):
[0000] 00 00 00 44 00 00 00 44 00 00 00 00 00 00 00 00 ...D...D ........
[0010] 04 00 20 00 70 00 02 00 00 00 00 0A 00 00 00 00 ....p... ........
[0020] 04 00 00 00 41 62 63 64 65 66 67 00 00 00 00 00 ....Abcd efg.....
[0030] 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ........ ........
[0040] 00 00 00 00 ....
espués de gestión de los tres órdenes de nuevo, que debería leer Abcdefg
con la primera lectura. ¿Derecha? Pero ejecutarlos de nuevo no cambia nada. Ahora puede suponer que la memoria que uso aún conserva los datos de funciones anteriores, pero obtengo el mismo resultado aunque ejecuto memset(Readbuff,0,sizeof(Readbuff))
antes de que ocurra el sys_read()
.
Supuse que quizás el LBA que trato de escribir tiene prohibido escribir, y leo el caché. Pero interar en LBA Adresses desde 0x00-0xFF no cambia nada - Eso significa que leo los mismos datos (Abcdefg
).
¿Conoces una implementación de ejemplo de lectura o escritura scsi con la interfaz genérica scsi?
muchas gracias. El ejemplo de sg3_utils me ayudó mucho y funciona ahora. – samuirai