AnyPS5/docs/dev/debt/libSceBeisobmf.md

libSceBeisobmf technical debt

Unknown function info

• libSceBeisobmf pending exports - 8 named callable exports remain among the 18 exports listed in the PS5 3.20 export table and cross-checked against PS5 firmware 13.60. Their signatures and behaviour are unverified; the declarations use the no-parameter unknown-signature convention and throw through NotImplemented_nid_no_patch.
• Ten box/decoder accessors are implemented from Ghidra 12.1.4 static analysis of libSceBeisobmf.sprx in PS5 firmware 13.60. The layouts are not verified against a console.
  • Box accessors: getchildbox at 0x3190 reads box+0x10; getnextbox at 0x31a0 reads box+0x20; getdiskoffset at 0x3220 reads box+0x80; getstate at 0x3200 reads box+0x8c; and gettype at 0x3210 reads box+0x90.
  • Member lookup at 0x7ce0 uses the member list at box+0x40 and cursor at box+0x50. Helpers 0x6ea0, 0x6ee0, and 0x6ec0 initialize, read, and advance the cursor through each member's +0x10 link. Helper 0x7040 reads the member name at +0x18. getmember_length at 0x3130 uses helper 0x7060 to read +0x68; getmember_type at 0x3170 uses helper 0x7050 to read +0x6c; and getmember_ptr at 0x3150 uses helper 0x7000 to select inline data at +0x58 or external data at +0x60 when the type is < 20 and its bit is set in mask 0x97800.
  • getflags32b at 0x31b0 looks up "flags", uses the member pointer helper at 0x7000, then reads three bytes. decoder_next_disk_offset at 0x30b0 returns 0xffffffff for a null decoder and otherwise reads decoder+0xc0.
  • Safe host results for null or unreadable inputs are: null for pointer accessors, 0 for scalar accessors, and 0xffffffff for decoder_next_disk_offset. The flags and decoder null results are visible in firmware; the remaining values are defensive fallbacks because exceptions must not escape these APS5_VABI exports. Guest fields are copied with GuestCopyIn_nid_no_patch; the member cursor is written with GuestCopyOut_nid_no_patch. Unreadable inputs and cyclic member lists fail inside the helper and become the safe fallback at the export boundary.