Update NETWORK-BOOT-TROUBLESHOOTING.md to clarify the boot process after start4.elf, emphasizing the importance of config.txt settings for kernel and initramfs. Introduce checks for GPU logging and ensure proper configuration for UART. Modify initramfs scripts to improve DHCP lease acquisition and ensure shell output is directed to the serial console. Update ensure-tftpboot-config-kernel-initrd.sh to enforce necessary config settings and link DTB files in serial-prefix directories for better device compatibility.
Introduce a new section in NETWORK-BOOT-TROUBLESHOOTING.md addressing issues where boot stops after start4.elf, detailing necessary config.txt settings for kernel and initramfs. Include instructions for ensuring the presence of required files in the TFTP root and a command to verify configurations on the LXC. Update initrd.img to reflect changes in the network boot process.
