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#!/usr/bin/env python3
"""Does the PSP validate the ring base and size it is given at ring creation?
Last host->PSP surface: the ring is created by writing base (C2PMSG_69/70) and size
(_71) and a create command to _64, whose low 16 bits are the PSP's own status. So the
firmware reports acceptance directly -- no inference needed.
A zero or huge size is the interesting case: the index bound demonstrated in pass 136 has to
be derived from this size, so a bogus size is the way to remove that bound. A base inside the
trusted region asks whether the PSP will fetch its own commands from protected memory.
Each case: destroy the ring, program the values, create, read the status. If creation is
accepted, submit one real command and see whether it executes -- an accepted-but-bogus ring
that still runs commands is the dangerous outcome.
argv[1] selects the case so one wedge cannot contaminate the others.
"""
import ctypes, glob, struct, sys, time
sys.path.insert(0,'/root/psp/hw')
from tinygrad import Device
import tinygrad.runtime.autogen.am.am as am
adev=Device["AMD"].iface.dev_impl; psp=adev.psp
RESP=864; FRAME=ctypes.sizeof(am.struct_psp_gfx_rb_frame); step=FRAME//4
P=psp.reg_pref
def alloc(n):
pa=adev.mm.palloc(n,align=0x1000,zero=True,boot=False); return pa,adev.paddr2mc(pa)
MAGIC=0x71000001
blob=open(glob.glob('/root/psp/contall/ta_42-0-0-6_1c874c3c*')[0],'rb').read()
ap_,amc=alloc(0x80000); cbuf,cbmc=alloc(0x8000); scratch,smc=alloc(0x1000)
n=(len(blob)+3)&~3
adev.vram.view(ap_,n)[:]=blob+b'\x00'*(n-len(blob)); adev.gmc.flush_hdp()
ring_mc=adev.paddr2mc(psp.ring_paddr); tmr_mc=adev.paddr2mc(psp.tmr_paddr)
CASES={
'control': (ring_mc, psp.ring_size),
'size0': (ring_mc, 0),
'size1': (ring_mc, 1),
'sizemax': (ring_mc, 0xFFFFFFFF),
'size4g': (ring_mc, 0x80000000),
'base_tmr':(tmr_mc, psp.ring_size),
'base0': (0, psp.ring_size),
'unalign': (ring_mc+1, psp.ring_size),
}
case=sys.argv[1]; base,size=CASES[case]
print('case=%s base=%#x size=%#x (real base %#x size %#x)'%(case,base,size,ring_mc,psp.ring_size), flush=True)
if adev.reg(f"{P}_71").read()!=0:
adev.reg(f"{P}_64").write(am.GFX_CTRL_CMD_ID_DESTROY_RINGS); time.sleep(0.05)
t0=time.time(); ready=False
while time.time()-t0<3:
if adev.reg(f"{P}_64").read() & 0x80000000: ready=True; break
print(' sOS ready before create: %s'%ready, flush=True)
adev.wreg_pair(P, "_69", "_70", base)
adev.reg(f"{P}_71").write(size)
adev.reg(f"{P}_64").write(am.PSP_RING_TYPE__KM << 16)
time.sleep(0.1)
st64=adev.reg(f"{P}_64").read()
status=st64 & 0xFFFF
print(' create: _64=%#-12x status=%#-8x -> %s'%(st64,status,
'ACCEPTED' if (st64 & 0x8000FFFF)==0x80000000 else 'rejected/not-ready'), flush=True)
if (st64 & 0x8000FFFF)!=0x80000000:
print(' RESULT %s: creation refused, ring unchanged'%case, flush=True); sys.exit(0)
# accepted -- does a real command execute through this ring?
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=cbmc&0xFFFFFFFF,cbmc>>32; t.cmd_buf_len=0x4000
adev.vram.view(psp.cmd_paddr, ctypes.sizeof(c))[:]=memoryview(c).cast('B')
adev.vram.view(psp.cmd_paddr+RESP,4,'I')[0]=0xA5A5A5A5
adev.vram.view(scratch,4,'I')[0]=0
f=am.struct_psp_gfx_rb_frame(fence_value=MAGIC,
cmd_buf_addr_lo=adev.paddr2mc(psp.cmd_paddr)&0xFFFFFFFF,
cmd_buf_addr_hi=adev.paddr2mc(psp.cmd_paddr)>>32,
fence_addr_lo=smc&0xFFFFFFFF, fence_addr_hi=smc>>32)
adev.vram.view(psp.ring_paddr, FRAME)[:]=bytes(memoryview(f).cast('B'))
adev.gmc.flush_hdp()
h0=adev.reg(f"{P}_81").read()
adev.reg(f"{P}_67").write(step)
t0=time.time(); rs=None
while time.time()-t0<2.0:
adev.gmc.flush_hdp()
v=struct.unpack_from('<I',bytes(adev.vram.view(psp.cmd_paddr+RESP,4)[:]),0)[0]
if v!=0xA5A5A5A5: rs=v; break
adev.gmc.flush_hdp()
fence=struct.unpack_from('<I',bytes(adev.vram.view(scratch,4)[:]),0)[0]
print(' RESULT %s: ACCEPTED, submit resp=%s fence=%s hb=%s'%(case,
hex(rs) if rs is not None else 'TIMEOUT', fence==MAGIC,
adev.reg(f"{P}_81").read()!=h0), flush=True)
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