Supercomputer System Design in Samsung Advanced Institute of Technology* Node Boot Architecture design for Green Supercomputer Project- Boot Architecture Design for RISC-V Architecture-based SoCs on Supercomputer Compute Nodes- Boot Architecture preliminary study for ARM Neoverse N2-based SoCs- Boot Firmware Stack pre-development using RISC-V VisionFive2 Reference Board- Development of EDK2, Oreboot, LinuxBoot(OSF), U-boot RISC-V Boot Firmware- U-boot VisionFive2 Board Opensource Contribution

Custom SoC Development Team in Samsung System LSI Division* A lead developer and system software architect of ExynosAuto SoC at Samsung Automotive team.- Linux Kernel Maintainer and Core BSP developer for Exynosauto SoC- Android Automotive Solution development both Native and Virtualization- Yocto Linux and IVI BSP platform development for Native and Virtualization- ExynosAuto v9 SoC BSP Lead Developer and Linux Kernel Open Source Contributor- Designed Yocto-based BSP architecture (layers) to support multiple customer's requirements and their architectures- Support for single binary BSP kernels on both v9 and v920 SoCs- Android Automotive GKI development lead and Google collaboration- ExynosAuto v920 EVT0 SoC Linux kernel Bring-up lead (Linux kernel Bring-up on Synopsys Zebu)

A-Project Team in Samsung System LSI Division* Automotive SoC Linux Kernel and BSP Development- Exynos Auto v9 SoC BSP Development(GPIO, I2C, SPI)- Designed Yocto-based BSP architecture- Onsite support for Daimler Gen20x project in Germany (as PO role for Samsung BSP team)

Software R&D Center in Samsung DS* ARTIK10 (Exynos 5422) / ARTIK5 (Exynos 3250) Kernel / IoT Platform Development- Porting Android-based u-boot to Linux platform (Fedora)- Porting Android-based Linux kernel to Linux platform (Fedora)- Development of DRM/DRI based display system (MIPI-DSI / HDMI)- Configure Mali GPU (T628/400) X11/Wayland system- Developed BSP (clock/GPIO/I2C/SPI/USB)- Developed Fedora root file system for IoT platformsIoT Business Team in Samsung SSIC* ARTIK71x(Nexell s5p6818) / ARTIK53x(Nexell s5p4418) Kernel / IoT Platform Development- Booting and maintenance of u-boot v2016 version- Linux kernel v4.1/v4.4 version Bring-up & Maintenance- Development of DRM/DRI based display system (MIPI-DSI/LVDS/HDMI/RGB)- Development of Mali GPU (Mali-400) X11/Wayland system- Developed Ubuntu 16.04 root file system for IoT platform- Yocto-based IoT platform development* ARTIK310s(sip-s31nx) kernel / IoT platform development- Booting and maintenance of u-boot v2018.05 version- Bringing up and maintaining Linux kernel v4.14 version- Clock Management Unit (CMU) driver development based on ARTIK310S Common Clock Framework- sm5011 PMIC driver development- Design and implementation of U-boot/Linux kernel device-tree structure- Developed Yocto-based build system (eMMC, SDBoot, Emmc-installer image generation)- Implemented kernel verification boot (based on FIT image)- Implemented kernel module signing- Implemented and validated DM-Verity (module/firmware/rootFS partition)

Kernel&BSP Part in Samsung Software R&D Center* World-First ARM64 Platform Enabling on Tizen 3.0- Linux Kernel Bring-up (3.17 Kernel) and Optimization on ARM Juno Board- Low memory Handling and Memory Compression using Zram- Upgraded Compiler (GCC4.9.2) to the latest version for ARM64 support and upgraded Toolchain Packages (glibc/binutils/gdb/gmp, etc.)- Build 800 packages that make up Tizen and apply ARM64 patches- ARM64bit performance analysis and compiler optimization (Binary Size/Memory Size)- Tizen ARM64bit Programming Guide- Collaboration with Intel developers to enable ARM64 builds in the Tizen Common Profile

Kernel&BSP Part in Samsung DMC R&D Center* Tizen Reference Kernel Development- Optimize eMMC/Filesystem (ext4/vfat) Performance- Memory (Readahead, Writeback) Optimization- Contiguous Memory Allocator (CMA) implementation and optimization- Tizen Reference Kernel(GS3-based) Public Open(1.0, 2.0, 2.1, 2.2, 2.2.1)* Android+Tizen Virtualization Project(Linux Kernel Para-Virtualization)- Virtualizing Android (Dom0) and Tizen (DomU) on a Nexus10 Project- Running Android and Tizen simultaneously on a Xen Hypervisor.- Developed a modification to the Android bootloader to enable hyp mode to jump to the Xen hypervisor.- Modify Android Ramdisk to boot Tizen (DomU) after Android (Dom0) has finished booting.- Modify Android Framebuffer Driver for Display virtualization to output screen from framebuffer from the corresponding Domain on each screen transition- Virtualize Display driver to meet GPU Sync* Implementing Checkpoint/Restore in Tizen WebApp (http://www.criu.org/)- Contribution of ARM part of CRIU opensource- Implemented WebApp's Checkpoint using CRIU- Modify and implement code for checkpoint in Webkit and EFL* Optimizing user memcpy with a 2D graphics accelerator- Implemented dmaengine (memcpy/memset) operation for Exynos g2d driver- Implemented ARM user page pinning to minimize the mapping overhead of user memory- Implemented mechanism for parallel copy using multiple memory-to-memory dma devices simultaneously- Implemented Asynchronous memory copy user API* Galaxy Gear1/Gear2 Model Preliminary Kernel Development- Galaxy Gear1 kernel pre-development based on 3.10 kernel version (BSP/USB driver)- Developed Galaxy Gear2 kernel based on 3.16 kernel version (BSP/USB driver)- Performance analysis and optimization with Perf/Ftrace/ARM Streamline- Developed kernel features for Smack(Security) support on VFAT filesystems* Tizen 3.0 Linux Kernel, Compiler, and Base Maintainer

Kernel&BSP Part in Samsung DMC R&D Center* NX300 Digital Camera DRIMe4 SoC Kernel Bring-up- Bootloader Development (u-boot)- 2.6.39-based Kernel Development/BSP Bring-up- Clock/GPIO/HRTimer/I2C/I2S/DMA BSP/Driver Development and Verification- Designware MMC/USB 3.0 Driver Porting- Migration to 3.5 version, the final commercialized kernel- Mechanism Guide for Fast booting

Multicore Lab in Samsung Advanced Institute of Technology* Semantic and Relation Based File System Development- Keyword Extraction from File Content and Metadata- Constructing Keyword Graph using Latent Semantic Analysis* Linux Kernel/BSP – Instant Boot on Tegra20 Board- Developing the part that optimizes the bootloader and loads the snapshot image- Creating a Snapshot image (swsusp) in the Kernel- Memory optimization to minimize Snapshot image- Device driver initcall optimization

Flash System Software / Software Center in Samsung CTO* Hybrid HDD/PCI Flash Cache Windows Device Driver- Storing file system meta data to OneNand regions on H-HDDs- Storing Windows Prefetch data on OneNand for fast booting- Implemented Storage Filter Driver to implement the above functions- Advance development of Flash Cache Driver to connect to PCI-e- Allocate data that is mainly subject to random I/O to the Flash Cache area- Improved application launch performance by allocating to the area used by ReadyBoost and Vista's Superfetch

Samsung Software Membership Daegu Region Manager- Selects outstanding university talents and places them in various business units of Samsung Electronics through various projects and technical training.