how to use SATA software reset command? (PIO)
Posted: March 30th, 2012, 4:47
by corner
I've tried to reset SATA-Controller with seting SRST-bit to 1 in Shadow Control Register. While waiting for the BSY-bit in Shadow Status Register be cleared to 0. However, I got 0xD8 everytime I read the Shadow Status Register.
My code follow:
- Code:
void software_reset(WORD portCtrl)
{
__asm
{
xor eax, eax
xor edx, edx
mov dx, word ptr[portCtrl]
mov al, _CONTROL_SRST_
out dx, al
}
}
void watch_dog(DWORD* pCount)
{
(*pCount)++;
if((*pCount) >= 0x100000)
{
__asm int 3
(*pCount) = 0;
}
}
void wait_until_ready(WORD portBase)
{
DWORD count = 0;
__asm
{
L_READ:
lea eax, dword ptr[count]
push eax
call watch_dog
mov dx, word ptr[portBase]
xor eax, eax
add dx, 0x7 //status
in al, dx
test al, (_STATUS_BSY_ | _STATUS_DRQ_)
jz L_RET
nop
nop
nop
jmp L_READ
}
L_RET:
__asm int 3
return;
}
void DriverEntry()
{
software_reset(0x3F6);
wait_until_ready(0x1F0);
}
Any info should be appreciated.
Re: how to use SATA software reset command? (PIO)
Posted: March 30th, 2012, 6:02
by guru
Re: how to use SATA software reset command? (PIO)
Posted: March 30th, 2012, 21:37
by corner
I read this document, just found out the intruduction of SStatus, the SStatus-Register looks like part of SCR-Register(It saids SCR0). However, Which Register I polling is Shadow-Status-Register.
Thank you anyway.
Re: how to use SATA software reset command? (PIO)
Posted: March 30th, 2012, 22:53
by corner
I got it !!
Detail here:
http://wiki.osdev.org/ATA_PIO_Mode#IDENTIFY_commandpart of explantion wrote:summary:
Resetting a drive / Software Reset
For non-ATAPI drives, the only method a driver has of resetting a drive after a major error is to do a "software reset" on the bus. Set bit 2 (SRST, value = 4) in the proper Control Register for the bus. This will reset both ATA devices on the bus. Then, you have to clear that bit again, yourself. The master drive on the bus is automatically selected. ATAPI drives set values on their LBA_LOW and LBA_HIGH IO ports, but are not supposed to reset or even terminate their current command.
Hope this could help someone who got the same perplexity like me.
Re: how to use SATA software reset command? (PIO)
Posted: March 30th, 2012, 23:34
by corner
By the words:
1. The Shadow-Status-Register of SATA-Controller is similar to Status-Register of PATA, just a different name.
2. The Shadow-Status-Register is a 8-bit Register, If you use it with a 16-bit instruction(like "in ax, 0x1F7") the result maybe uncertainty.(If the incorrect instruction executed under VMWare-Guest-OS, the VMWare will stop itself, you can verify this situation.)
Share my experience of SATA study.