Modern heterogeneous SoCs (System-on-Chip) contain a set of Hard IPs (HIPs) surrounded by an FPGA fabric for hosting custom Hardware Accelerators (HAs). However, efficiently managing such HAs in an embedded Linux environment involves creating and building custom device drivers specific to the target platform, which negatively impacts development cost, portability and time-to-market. To address this issue, we present LEOSoC, an open-source cross-platform embedded Linux library. LEOSoC reduces the development effort required to interface HAs with applications and makes SoCs easy to use for an embedded software developer who is familiar with the semantics of standard POSIX threads. Using LEOSoC does not require any specific version of the Linux kernel, nor to rebuild a custom driver for each new kernel release. LEOSoC consists of a base hardware system and a software layer. Both hardware and software are portable across SoC from various vendors and the library recognizes and auto-adapts to the target SoC platform on which it is running. Furthermore, LEOSoC allows the application to partially or completely change the structure of the HAs at runtime without rebooting the system by leveraging the underlying platforms? support for dynamic full/partial FPGA reconfigurability. The system has been tested on multiple COTS (Commercial Off The Shelf) boards from different vendors, each one running different versions of Linux and, therefore, proving the real portability and usability of LEOSoC in a specific industrial design.