Amlogic TF-A UART logs obfuscation on some boards (OTP?)
A ZTE B700V7-2017 user reported that it mangled UART logs:
.......................................................................................set vcck to 1200 mv
set vddee to 1200 mv
[U-Boot logs ...]
They successfully dumped BL1. We fed the dump into Ghidra:
/* WARNING: Globals starting with '_' overlap smaller symbols at the same address */
uint serial_putc(uint c)
{
byte *efuse_data;
/* Thanks to arzamas-16[m] for helping! */
efuse_data = (byte *)get_efuse_mirror_ptr();
if ((efuse_data[5] >> 1 & 1) != 0) {
c = L'.';
}
do {
} while ((_DAT_c81004cc >> 0x15 & 1) != 0);
_DAT_c81004c0 = c & 0xff;
return c;
}
It's known to happen on: - ZTE B700V7 - ZTE ZXV10 B860H V5