Qemu load OpenSBI debug error

I am using QEMU to build sifive_ U simulates the environment to debug opensbi, but when debugging through the GDB remote end, the code is stuck in the opensbi cold start code. When I separate GDB, QEMU can run normally

OpenSBI v1.0-92-g9dc5ec5
   ____                    _____ ____ _____
  / __ \                  / ____|  _ \_   _|
 | |  | |_ __   ___ _ __ | (___ | |_) || |
 | |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
 | |__| | |_) |  __/ | | |____) | |_) || |_
  \____/| .__/ \___|_| |_|_____/|____/_____|
        | |
        |_|

Platform Name             : SiFive HiFive Unleashed A00
Platform Features         : medeleg
Platform HART Count       : 2
Platform IPI Device       : aclint-mswi
Platform Timer Device     : aclint-mtimer @ 1000000Hz
Platform Console Device   : sifive_uart
Platform HSM Device       : ---
Platform Reboot Device    : gpio-restart
Platform Shutdown Device  : ---
Firmware Base             : 0x80000000
Firmware Size             : 1320 KB
Runtime SBI Version       : 0.3

Domain0 Name              : root
Domain0 Boot HART         : 1
Domain0 HARTs             : 0*,1*
Domain0 Region00          : 0x0000000002000000-0x000000000200ffff (I)
Domain0 Region01          : 0x0000000080000000-0x00000000801fffff ()
Domain0 Region02          : 0x0000000000000000-0xffffffffffffffff (R,W,X)
Domain0 Next Address      : 0x0000000080200000
Domain0 Next Arg1         : 0x0000000082200000
Domain0 Next Mode         : S-mode
Domain0 SysReset          : yes

Boot HART ID              : 1
Boot HART Domain          : root
Boot HART Priv Version    : v1.10
Boot HART Base ISA        : rv64imafdc
Boot HART ISA Extensions  : none
Boot HART PMP Count       : 16
Boot HART PMP Granularity : 4
Boot HART PMP Address Bits: 54
Boot HART MHPM Count      : 0
Boot HART MIDELEG         : 0x0000000000000222
Boot HART MEDELEG         : 0x000000000000b109