Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) ==========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) ELF Note PowerPC Namespace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) ==========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) The PowerPC namespace in an ELF Note of the kernel binary is used to store
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) capabilities and information which can be used by a bootloader or userland.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) Types and Descriptors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) ---------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) The types to be used with the "PowerPC" namesapce are defined in [#f1]_.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	1) PPC_ELFNOTE_CAPABILITIES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Define the capabilities supported/required by the kernel. This type uses a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) bitmap as "descriptor" field. Each bit is described below:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) - Ultravisor-capable bit (PowerNV only).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	#define PPCCAP_ULTRAVISOR_BIT (1 << 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) Indicate that the powerpc kernel binary knows how to run in an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) ultravisor-enabled system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) In an ultravisor-enabled system, some machine resources are now controlled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) by the ultravisor. If the kernel is not ultravisor-capable, but it ends up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) being run on a machine with ultravisor, the kernel will probably crash
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) trying to access ultravisor resources. For instance, it may crash in early
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) boot trying to set the partition table entry 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) In an ultravisor-enabled system, a bootloader could warn the user or prevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) the kernel from being run if the PowerPC ultravisor capability doesn't exist
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) or the Ultravisor-capable bit is not set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) References
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) ----------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) .. [#f1] arch/powerpc/include/asm/elfnote.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)