It may be because the device information is incomplete. You can mount based on specific device information, not necessarily /dev/sda. In addition, what file system is your U disk? If it is NTFS, arm may not be able to recognize it. If it is fat/fat32, you can use mount -f vfat to mount it.
ARM development board, conceptually, is very similar to software outsourcing (software outsourcing refers to software outsourcing providers in order to concentrate on core competitiveness business, reduce project costs, and at the same time improve the quality of project implementation. Subcontract all or part of the work in your software project to a suitable software company for completion).
With the rapid development of information technology and the improvement of people's living standards, the development of medical electronic equipment has been greatly promoted. The development trend of today's medical electronic equipment is high precision, real-time, low power consumption and small size. Size, as the core of medical electronic equipment, MCU (microprocessor) is also evolving along with this development trend. From the early 8-bit MCU to the current 32-bit RISC (reduced instruction set computer) MCU. According to the needs of the market, the American ADI Company has recently launched a microprocessor ADμC7024 based on the ARM (Advanced Reduced Instruction Set Computer) core, which is an outstanding representative of the current 32-bit RISC MCU. ADμC7024's excellent processing capabilities, integration of numerous on-chip peripheral devices and low power consumption of the chip are fully qualified to meet the current needs of medical electronic equipment and future development goals.