/**************************************************************************************************
* @fn sblInit
*
* @brief Boot Loader initialization.
*
* input parameters
*
* None.
*
* output parameters
*
* None.
*
* @return TRUE if there is a valid RC image; FALSE otherwise.
*/
uint8 sblInit(void)
{
aesLoadKey();
#if defined AES_TEST_VECS
uint8 checkSig[KEY_BLENGTH] = {
0xB9, 0xD7, 0x89, 0x67, 0x04, 0xBC, 0xFA, 0x20, 0xB2, 0x10, 0x36, 0x74, 0x45, 0xF9, 0x83, 0xD6
};
imgHdr.len = 1;
while (1)
{
aesSignature(testSig);
if (memcmp(testSig, checkSig, KEY_BLENGTH)) // If signature generated is not value expected.
{
ASM_NOP;
}
}
#else
SBL_READ_IMG_HDR();
return checkRC();
#endif
}
/**************************************************************************************************
* @fn imgAuth
*
* @brief Run the AES CTR decryption over the image area specified.
* @brief Run the AES CRC-MAC calculation over the image specified and set the image
* ready-to-run if the Signature is verified.
*
* input parameters
*
* @param imgSel - Image select: 0 for Image-A and 1 for Image-B.
* @param imgHdr - Pointer to the Image Header corresponding to the image select.
*
* output parameters
*
* None.
*
* @return TRUE if the image Signature verifies; FALSE otherwise.
*/
static uint8 imgAuth(uint8 imgSel, img_hdr_t *imgHdr)
{
if ((imgHdr->crc0 == 0) || (imgHdr->crc0 == 0xFFFF))
{
return FALSE;
}
if (imgHdr->crc0 != imgHdr->crc1)
{
aesLoadKey();
aes_hdr_t aesHdr;
HalFlashRead(ImgPageBeg[imgSel], BEM_AES_OSET, (uint8 *)&aesHdr, sizeof(aes_hdr_t));
// Image length in 3 bytes, MSB to LSB order - the Signature bytes are not to be included.
uint32 imageLen = (uint32)HAL_FLASH_PAGE_SIZE * imgHdr->res[0] - KEY_BLENGTH;
aesHdr.spare[0] = ((uint8 *)&imageLen)[0];
aesHdr.spare[1] = ((uint8 *)&imageLen)[1];
aesHdr.spare[2] = ((uint8 *)&imageLen)[2];
aesHdr.spare[3] = imgHdr->res[0];
if (aesSignature(imgSel, &aesHdr))
{
uint16 crc[2] = { 0xFFFF, imgHdr->crc0 };
BEM_NVM_SET(ImgPageBeg[imgSel], (uint8 *)crc, 4);
BEM_NVM_GET(ImgPageBeg[imgSel], (uint8 *)&imgHdr, 4);
}
}
return (imgHdr->crc0 == imgHdr->crc1);
}
/**************************************************************************************************
* @fn imgCrypt
*
* @brief Run the AES CTR decryption over the image area specified.
*
* input parameters
*
* @param imgSel - Image select: 0 for Image-A and 1 for Image-B.
* @param imgHdr - Pointer to the Image Header corresponding to the image select.
*
* output parameters
*
* None.
*
* @return None.
*/
static void imgCrypt(uint8 imgSel, img_hdr_t *imgHdr)
{
aesLoadKey();
uint8 pgEnd = imgHdr->res[0] + ImgPageBeg[imgSel];
if (imgSel == 0)
{
pgEnd += ImgPageLen[1];
}
for (uint8 pgNum = ImgPageBeg[imgSel]; pgNum < pgEnd; )
{
BEM_NVM_GET(pgNum, pageBuf, HAL_FLASH_PAGE_SIZE);
// EBL is used to encrypt the image in SBL_RW_BUF_LEN blocks, so it must be decrypted likewise.
for (uint8 blk = 0; blk < (HAL_FLASH_PAGE_SIZE / SBL_RW_BUF_LEN); blk++)
{
if ((pgNum == ImgPageBeg[imgSel]) && (blk == 0))
{
aesCrypt(1, pageBuf + ((uint16)SBL_RW_BUF_LEN * blk));
}
else
{
aesCrypt(0, pageBuf + ((uint16)SBL_RW_BUF_LEN * blk));
}
}
HalFlashErase(pgNum);
BEM_NVM_SET(pgNum, pageBuf, HAL_FLASH_PAGE_SIZE);
pgNum++;
if ((imgSel == 0) && (pgNum == ImgPageBeg[1]))
{
pgNum += ImgPageLen[1];
}
}
}