memdiskfind

memdiskfind

memdiskfind is a specialized utility primarily associated with the SYSLINUX / ISOLINUX project. Its core function is to programmatically locate a memdisk image that has been previously loaded into system memory by the memdisk utility.

The memdisk utility itself is designed to boot entire disk images (e.g., floppy images, hard disk images, or ISO files) directly from RAM. When such an image is loaded, memdiskfind can then be invoked to determine its exact memory address. This capability is crucial in advanced boot environments or multi-stage boot processes, where subsequent bootloaders, kernels, or applications need to know the precise location of the in-memory disk image to access its contents and continue the boot sequence. It operates by scanning specific memory regions for the unique signature of a loaded memdisk image. Unlike typical Linux commands, memdiskfind is generally not used interactively but rather as an internal component within boot scripts or the memdisk program's logic.

memdiskfind is not a general-purpose Linux command for interactive shell use. It is highly specialized and specific to the SYSLINUX/ISOLINUX boot environment and the memdisk utility. It serves primarily as an internal helper within boot processes. It requires a memdisk image to be loaded into memory by the memdisk utility for it to have any meaningful function. Running it in a standard Linux environment without memdisk context will yield no useful result or may indicate no image found.

memdiskfind is rarely, if ever, executed directly by users from a conventional command-line interface. Instead, it functions as an internal subroutine or mechanism within the memdisk utility itself, or it might be called implicitly by custom boot scripts (e.g., within syslinux.cfg configurations) during the boot process. Its purpose is to internally provide the memory address of the loaded memdisk image to other boot components—such as the kernel, an initramfs, or a subsequent bootloader—that need to interact with the contents of the in-memory disk image. Due to this specialized, internal role, memdiskfind does not accept user-defined options or arguments.

memdiskfind is an integral component of the SYSLINUX Project, a suite of bootloaders primarily maintained by H. Peter Anvin. It developed alongside the memdisk utility, which was created to address the need for booting various disk images from RAM, especially in environments where direct disk access was inconvenient or impossible (e.g., netbooting). Its functionality has remained consistent since its inception: to programmatically locate the memdisk image in memory, facilitating complex boot scenarios and chaining of bootloaders. Its development is tied to the evolution and maintenance of the broader SYSLINUX project.

memdisk(1), syslinux(8), isolinux(8)