if i'm not mistaken, the type of byteswap used is byteswap 16 (16 bytes) in that case, naehrwert has published his ps3_hdd POC tool which includes the function in a clean and tidy way of his
lemme see if i can fetch it.
/*! Swap u16 endianness. */
static void _es16_buffer(u8 *buf, u32 length)
u16 *ptr = (u16 *)buf;
for(i = 0; i < length/2; i++)
ptr[i] = _ES16(ptr[i]);
"Whoever has ears, let them hear."