运行具有多个核心的火箭芯片

Question

以下程序计算核心数并打印它。如果我编译程序

riscv64-unknown-elf-gcc -static -mcmodel=medany -Ttext 0x80000000
minimal.S -nostdlib -nostartfiles -o minimal.riscv.elf

并使用spike

运行它

spike -p2 minimal.riscv.elf

输出

# of Cores: 2

如果我使用火箭芯片生成器（使用4234cff）构建的火箭芯片做同样的事情

make CONFIG=DualCoreConfig

并在其上运行程序

./emulator-rocketchip-DualCoreConfig minimal.riscv.elf

输出

# of Cores: 1

虽然它应该是2.我是否必须以不同方式构建火箭芯片，还是需要在某处激活另一个核心？

    .data
    .align 4
num_harts: .dword 0
message: .ascii "# of Cores: "
number_of_cores: .ascii "0"
end: .ascii "\n"
    .align 4
syscall_data: .space 64

    .text
    .globl _start

_start:
        csrr    a0, mhartid          # get core id
        la      t1, num_harts        # load address of num_harts
        li      t2, 1                # set register t2=1
        amoadd.w zero, t2, (t1)      # use atomar instruction to count and write # of cores

        rdcycle t0                   # read cycles
        li      t1, 50000            # set t1=50000
        add     t1, t0, t1           # add 50000 to read cycles and store in t1
3:      rdcycle t0                   # read cycles
        blt     t0, t1, 3b           # until t0 == t1
while:  bne     a0, zero, while      # let all cores exept core 0 run infinitely
        la      t0, num_harts        # load address of num_harts
        lw      a0, 0(t0)            # set a0=num_harts
        add     a0, a0, 48           # convert # of cores to ascii
        la      t0, number_of_cores  # get address of reserved string
        sb      a0, 0(t0)            # write # of cores to number_of_cores
        add     a7, zero, 64         # set syscall for write
        add     a0, zero, 1          # set a0 to 1
        la      a1, message          # set a1 to address of message
        add     a2, zero, 17         # set length of address
        la      t4, syscall_data     # end of string
        sd      a7, 0(t4)            # write values to memory
        sd      a0, 8(t4)
        sd      a1, 16(t4)
        sd      a2, 24(t4)
        la      t0, tohost           # execute syscall
        sd      t4, (t0)
1:      ld      t5, 64(t0)
        beq     t5, zero, 1b
        sd      zero, 64(t0)
        add     a0, zero, 1          # end program
        sd      a0, (t0)
3:      j       3b


.section ".tohost","aw",@progbits
.align 6
.globl tohost
tohost: .dword 0
.align 6
.globl fromhost
fromhost: .dword 0