bootctlAlone

Standalone (or multi-call) bootctl compatible with Android boot HAL CLI.

• Entry: bootctl_main(int argc, char **argv) for use when linked into ksud; define BOOTCTL_STANDALONE for a standalone executable with main().
• Slot detection: Reads /proc/cmdline for androidboot.slot_suffix= / slot_suffix= (e.g. _a / _b). No dependency on boot_control HAL or libcutils.
• Commands: hal-info, get-number-slots, get-current-slot, get-active-boot-slot, get-suffix SLOT. Write operations (set-active-boot-slot, mark-boot-successful, etc.) are not supported in fallback mode and return exit code 69 (EX_UNAVAILABLE).