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| boot_process [2026/02/22 03:51] – whitetailani | boot_process [2026/02/26 06:02] (current) – Added newlines after steps 3 and 4 to fix formatting benjamin |
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| 1. U-Boot starts up and loads the kernel from the [[storage#rootfs|rootFS]] microSD card.\\ | 1. U-Boot starts up and loads the kernel from the [[storage#rootfs|rootFS]] microSD card.\\ |
| 2. systemd attempts to mount the [[storage#initFS|initFS]] by searching for any partitions named ''%%init%%''. If it cannot find any volumes after 10 seconds, it shuts down. | 2. The kernel loads systemd from /usr/lib/systemd/systemd.\\ |
| 3. The kernel calls to /sbin/init, which later calls ''%%/init/tools/initexec.sh startup%%''. If the ''%%startup%%'' argument is not passed, the script tells you the only valid argument is ''%%startup%%'', then exits.\\ | 3. systemd attempts to mount the [[storage#initFS|initFS]] by searching for any partitions named ''%%init%%''. If it cannot find any volumes after 90 seconds, it shuts down.\\ |
| 4a. /init/tools/initexec.sh sets up a bunch of aliases and environment variables.\\ | 4. The kernel calls to /sbin/init, which later calls ''%%/init/tools/initexec.sh startup%%''. If the ''%%startup%%'' argument is not passed, the script tells you the only valid argument is ''%%startup%%'', then exits.\\ |
| 4b. initexec.sh ensures necessary directories are created, then checks and sets the device's distribution channel.\\ | 5a. /init/tools/initexec.sh sets up a bunch of aliases and environment variables.\\ |
| 4c. It calls a function ''%%do_startup%%'', which checks if there is software to run, and if not, installs it via a function ''%%install_archive%%''. This function misspells "archive" to "archvie" in an echo log.\\ | 5b. initexec.sh ensures necessary directories are created, then checks and sets the device's distribution channel.\\ |
| 4d. It checks if ''%%/init/tmp/reboot.flg exists%%'', and if so, reboots the device.\\ | 5c. It calls a function ''%%do_startup%%'', which checks if there is software to run, and if not, installs it via a function ''%%install_archive%%''. This function misspells "archive" to "archvie" in an echo log.\\ |
| 4e. It calls every script located in /init/autorun/, launching /efad/pgm/NxProx (the CapMetro software), then echoes "Startup completed".software).\\ | 5d. It checks if ''%%/init/tmp/reboot.flg exists%%'', and if so, reboots the device.\\ |
| | 5e. It calls every script located in /init/autorun/, launching /efad/pgm/NxProx (the CapMetro software), then echoes "Startup completed".software).\\ |
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| It is trivially easy to hijack this init sequence by modifying initexec.sh or just inserting a script into /init/autorun. | It is trivially easy to hijack this init sequence by modifying initexec.sh or just inserting a script into /init/autorun. |
