entry.asm
storage-db_tcore/codes/os/src/entry.asm
    .section .text.entry
    .globl _start
_start:
    # tp:hart_id 
    mv a0,tp # RustSBI
    #mv tp, a0 # OpenSBI
    la a1, boot_stack_top
    slli a0, a0, 15 # hart_id* stacksize
    add a0, a0, a1
    # a0 = boot_stack_top + hart_id* stacksize
    mv sp, a0
    call rust_main

    .section .bss.stack
    .globl boot_stack
boot_stack:
    .space 4096 * 8
    .globl boot_stack_top
boot_stack_top:
boot_stack2:
    .space 4096 * 8
    .globl boot_stack_top2
boot_stack_top2: