This RFC is trying to clean up the usage of the internal functions used to manage the protocol and handle lifetimes. Currently we arbitrarily use either InstallProtocol, InstallMultipleProtocol and a combination of efi_add_protocol, efi_create_handle, efi_delete_handle(). The latter is the most problematic one since it blindly removes all protocols from a handle and finally the handle itself. This is prone to coding errors Since someone might inadvertently delete a handle while other consumers still use a protocol.
InstallProtocol is also ambiguous since the EFI spec only demands InstallMultipleProtocol to test and guarantee a duplicate device path is not inadvertently installed on two different handles. So this patch series is preparing the ground in order for InstallMultipleProtocol and UnInstallMultipleProtocol to be used internally in U-Boot.
There is an example on bootefi.c demonstrating how the cleanup would eventually look like. If we agree on the direction, I'll clean up the remaining callsites with InstallMultipleProtocol.
Size differences between old/new binary show that eventually we will manage to reduce the overall code size by getting rid all the unneeded EFI_CALL invocations
add/remove: 4/0 grow/shrink: 1/6 up/down: 1128/-892 (236) Function old new delta __efi_install_multiple_protocol_interfaces - 496 +496 __efi_uninstall_multiple_protocol_interfaces - 412 +412 efi_uninstall_multiple_protocol_interfaces_ext - 108 +108 efi_install_multiple_protocol_interfaces_ext - 108 +108 efi_run_image 288 292 +4 efi_initrd_register 220 212 -8 efi_console_register 344 336 -8 efi_disk_add_dev.part 644 632 -12 efi_root_node_register 256 240 -16 efi_uninstall_multiple_protocol_interfaces 472 84 -388 efi_install_multiple_protocol_interfaces 544 84 -460 Total: Before=547442, After=547678, chg +0.04% add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) Data old new delta Total: Before=101061, After=101061, chg +0.00% add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) RO Data old new delta Total: Before=42925, After=42925, chg +0.00%
Ilias Apalodimas (2): efi_loader: define internal implementation of install/uninstallmultiple cmd: replace efi_create_handle/add_protocol with InstallMultipleProtocol
cmd/bootefi.c | 13 ++- include/efi.h | 2 + include/efi_loader.h | 6 +- lib/efi_loader/efi_boottime.c | 180 ++++++++++++++++++++++++------- lib/efi_loader/efi_capsule.c | 15 +-- lib/efi_loader/efi_console.c | 14 +-- lib/efi_loader/efi_disk.c | 10 +- lib/efi_loader/efi_load_initrd.c | 15 ++- lib/efi_loader/efi_root_node.c | 44 ++++---- 9 files changed, 203 insertions(+), 96 deletions(-)