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#!/usr/bin/env python3
"""Which host field drives FP cmd3's output count, and can it be made large?
The six-TA differential showed FP cmd3 returns dword[+4] = 8 with a zeroed buffer and 4 with
the 'big' profile, so some host input reaches a count-like value. This isolates which input
field does it by varying one dword at a time, and then tries to push that value up.
Relevance: the static reading says the length FP passes to the SYS_DRV 0x33 descriptor is the
constant 0x10. If a host field can drive a length-like quantity, that reading needs revisiting.
Safety: ordinary INVOKEs to FP only. FP does not emit SYS_DRV opcode 0xd.
"""
import argparse, glob, os, struct, sys
def main():
ap = argparse.ArgumentParser()
ap.add_argument('--dir', default='/root/psp/contall')
a = ap.parse_args()
from tinygrad import Device
import tinygrad.runtime.autogen.am.am as am
adev = Device["AMD"].iface.dev_impl; psp = adev.psp
def alloc(n):
pa = adev.mm.palloc(n, align=0x1000, zero=True, boot=False)
return pa, adev.paddr2mc(pa)
def load(blob):
ap_, amc = alloc(0x80000); cp, cmc = alloc(0x8000)
n=(len(blob)+3)&~3
adev.vram.view(ap_,n)[:] = blob + b'\x00'*(n-len(blob)); adev.gmc.flush_hdp()
c = am.struct_psp_gfx_cmd_resp(cmd_id=am.GFX_CMD_ID_LOAD_TA); t=c.cmd.cmd_load_ta
t.app_phy_addr_lo,t.app_phy_addr_hi = amc&0xFFFFFFFF, amc>>32; t.app_len=len(blob)
t.cmd_buf_phy_addr_lo,t.cmd_buf_phy_addr_hi = cmc&0xFFFFFFFF, cmc>>32; t.cmd_buf_len=0x8000
try:
r=psp._ring_submit(c); return r.resp.status&0xFFFFFFFF, r.resp.session_id, cp
except Exception as e:
try: return int(str(e).strip().split()[-1])&0xFFFFFFFF, None, cp
except Exception: return -1, None, cp
def invoke(sid, shm, cid, mutate):
buf = bytearray(0x2000); struct.pack_into('<I', buf, 0, cid)
mutate(buf)
adev.vram.view(shm, len(buf))[:] = bytes(buf); adev.gmc.flush_hdp()
c = am.struct_psp_gfx_cmd_resp(cmd_id=am.GFX_CMD_ID_INVOKE_CMD)
iv=c.cmd.cmd_invoke_cmd; iv.session_id, iv.ta_cmd_id = sid, cid
try:
r=psp._ring_submit(c); st=r.resp.status&0xFFFFFFFF
except Exception as e:
try: st=int(str(e).strip().split()[-1])&0xFFFFFFFF
except Exception: st=-1
adev.gmc.flush_hdp()
return st, bytes(adev.vram.view(shm,32)[:])
cands = glob.glob(os.path.join(a.dir,'ta_19-0-0-8_7e8be282*'))
blob = open(cands[0],'rb').read()
st, sid, shm = load(blob)
print('FP load: %#x sid=%s' % (st, sid))
if st != 0: return 2
base_st, base_out = invoke(sid, shm, 3, lambda b: None)
print('baseline cmd3: st=%#x out=%s' % (base_st, base_out[:16].hex()))
print('\nvarying one dword at a time (value 0x800), reporting changed outputs:')
changed = []
for off in range(4, 0x60, 4):
def mut(b, o=off): struct.pack_into('<I', b, o, 0x800)
s2, out = invoke(sid, shm, 3, mut)
if out[:16] != base_out[:16]:
changed.append((off, out[:16].hex()))
print(' +%#-4x -> st=%#x out=%s' % (off, s2, out[:16].hex()))
if not changed:
print(' (none)')
# push the responsible field up
if changed:
off = changed[0][0]
print('\nscaling field +%#x:' % off)
for v in (0x10, 0x80, 0x100, 0x800, 0x10000, 0xFFFFFFFF):
def mut(b, o=off, val=v): struct.pack_into('<I', b, o, val)
s2, out = invoke(sid, shm, 3, mut)
print(' value %#-12x -> st=%#-12x out=%s' % (v, s2, out[:16].hex()))
c = am.struct_psp_gfx_cmd_resp(cmd_id=am.GFX_CMD_ID_UNLOAD_TA)
c.cmd.cmd_unload_ta.session_id = sid
try: psp._ring_submit(c)
except Exception: pass
return 0
if __name__ == '__main__':
sys.exit(main())
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