The baud rate initially applied by the Preloader is defined in the following file under the Preloader/U-Boot source tree.
File name: uboot-socfpga\include\configs\socfpga_common.h
00346|/*
00347| * NS16550 Configuration
00348| /
00349|#define CONFIG_SYS_NS16550
00350 |#ifdefine CONFIG_SYS_NS16550
00351|#define UART0_BASE SOCFPGA_UART0_ADDRESS
00352|#define CONFIG_SYS_NS16550_SERIAL
00353|#define CONFIG_SYS _NS16550_REG_SIZE -4
00354|#define CONFIG_CONS_INDEX 1
00355|#define CONFIG_SYS_NS16550_COM1 UART0_BASE
00356|#define CONFIG_SYS_BAUDRATE_ TABLE {4800, 9600, 19200, 38400, 57600, 115200}
00357|#if defined(CONFIG_SOCFPGA_VIRTUAL_TARGET)
00358|#define CONFIG_SYS_NS16550_CLK 1000000
00359|#else
00360|#define CONFIG_SYS_NS16550_CLK (cm_l4_sp_clock)
00361|#endif
00362|#define CONFIG_BAUDRATE 115200
00363|#endif / CONFIG_SYS_NS16550 */
bsp-editor options are not supported, so the definition in the source code must be rewritten.
If you change line 362 in the above source code as follows, the default setting should be set to 9600.
#define CONFIG_BAUDRATE 115200
↓
#define CONFIG_BAUDRATE 9600
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Category: SoC
Tool: SoC EDS
Device: Cyclone® V