vmlinux

vmlinux is a non-distributable, internal object file produced during the build process of the Linux kernel. It contains the uncompressed, executable kernel code and data, but it is not a bootable kernel image itself. The vmlinux file is essential for debugging and for use by various kernel development tools. It represents the complete kernel symbol table and all the compiled object code before any linking or stripping of symbols occurs.

Developers often use vmlinux to perform tasks such as analyzing kernel memory dumps, debugging live kernel instances using tools like GDB, and for generating kernel symbol maps. Tools like `objdump` and `readelf` can be used to inspect the contents of vmlinux. While it contains the core kernel logic, it lacks the necessary bootloader components and file system structures required to load and run independently on hardware. The bootable kernel image, typically named `vmlinuz`, is derived from vmlinux through further processing, including compression and the addition of a bootloader. Therefore, vmlinux serves as an intermediate artifact, crucial for understanding and manipulating the kernel's internal structure.