Actually AFAIK the APU2 SoC includes a PSP already, the APU1 is still free of that. But even the APU1 SoC has a small LM32 core that you have no source for, see

Actually AFAIK the APU2 SoC includes a PSP already, the APU1 is still free of that. But even the APU1 SoC has a small LM32 core that you have no source for, see Rudolf Marek's CCC talk "AMD x86 SMU firmware analysis".