STI5518 Firmware modification

[chandra]

I read the firmware by jtag from a working STB with STI5518 chip.I want to add a Uart protocal at the firmware. The protocal is as follows:

int SSSP_DoCommand07(void)
{
char szFront[16];
unsigned char ucaReply[32];
unsigned short wLen;
int i, j, k, nErrorCnt;
DWORD dwWriteSize, dwReadSize;
unsigned char *p;
DWORD ident;

s_dwActiveFrequency = s_dwCurrentFrequency;

s_ucaUARTWriteBuffer[0] = 0x07;
s_ucaUARTWriteBuffer[1] = 0x06;
s_ucaUARTWriteBuffer[2] = (s_wCurrentDegree >> 8) & 0xFF;
s_ucaUARTWriteBuffer[3] = (s_wCurrentDegree >> 0) & 0xFF;
s_ucaUARTWriteBuffer[4] = (s_dwCurrentFrequency >> 8) & 0xFF;
s_ucaUARTWriteBuffer[5] = (s_dwCurrentFrequency >> 0) & 0xFF;
s_ucaUARTWriteBuffer[6] = (s_wCurrentServiceID >> 8) & 0xFF;
s_ucaUARTWriteBuffer[7] = (s_wCurrentServiceID >> 0) & 0xFF;

p = &s_ucaUARTWriteBuffer[0];
s_ucaUARTWriteBuffer[8] = p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4] ^ p[5] ^ p[6] ^ p[7];
STUART_Flush(s_SerialHandle);
STUART_Write(s_SerialHandle, s_ucaUARTWriteBuffer, 9, &dwWriteSize, 500);
for (j = 0;j < 1; j++) {
s_ucWaitStatus = 1;
ucaReply[0] = 0x00;
dwReadSize = 0;
for (k = 0; k < 10; k++) {
STUART_Read(s_SerialHandle, &ucaReply[0], 1, &dwReadSize, 100);
if (dwReadSize == 1) break;
if (s_ucSSSPStatus == 0) break;
}
s_ucWaitStatus = 0;
if (k >= 10) return -2;
if ( (dwReadSize != 1) || (ucaReply[0] != 0xF7)) {
sprintf(szFront, "F%03d", dwReadSize);
szFront[4] = (char)(0xff);
FRONT_PrintData(szFront);
return -1;
}
STUART_Read(s_SerialHandle, &ucaReply[1], 18, &dwReadSize, 1000);
if (dwReadSize == 18) {
p = &ucaReply[3];
nErrorCnt = 0;
if ((p[3] != ((p[0]+p[1]+p[2]) & 0xFF))) nErrorCnt |= 0x01;
if ((p[7] != ((p[4]+p[5]+p[6]) & 0xFF))) nErrorCnt |= 0x02;
if ((p[11] != ((p[8]+p[9]+p[10]) & 0xFF))) nErrorCnt |= 0x04;
if ((p[15] != ((p[12]+p[13]+p[14]) & 0xFF))) nErrorCnt |= 0x08;
if (nErrorCnt == 0) {
if (memcmp(s_ucaOldCW, &ucaReply[3], 16) != 0) {
sprintf(szFront, "SETK");
szFront[4] = (char)(0xff);
FRONT_PrintData(szFront);
Descrypt(&ucaReply[3], &ucaReply[3+8], 0);
} else {
sprintf(szFront, "NOSE");
szFront[4] = (char)(0xff);
FRONT_PrintData(szFront);
}
memcpy(s_ucaOldCW, &ucaReply[3], 16);
return 0;
} else {
sprintf(szFront, "E%d%02d", nErrorCnt, dwReadSize);
szFront[4] = (char)(0xff);
FRONT_PrintData(szFront);
return -1;
}
} else {
sprintf(szFront, "F%03d", dwReadSize);
szFront[4] = (char)(0xff);
FRONT_PrintData(szFront);
return -1;
}
}

return -1;
}

=============================

How can I add this.
I have the bin file of this protocal also.
I dissassemble the STB flash bin file.Then where to add?
Anybody can help me.

 

[mkrtich.nazaryan]

Hi chandra,
Unfortunately I can't answer your question, but I want to ask you the other one. I'm new in digital TV, trying to understand how work digital set-top-box. In level of schematic circuit I already understand working process of STB. Now I'd would like to understand software level. Could you please suggest me some books or articles about STB firmware or STB programing.

Many thanks

 

[mkrtich.nazaryan]

Hi, Could you please tell which software did you use to read firmware from STi5518, and Can I write firmware into STi5518 by same software.

Thanks.

 

[bighrissen]

Thanks.Thanks.Thanks.Thanks.