.section .text._start, "ax"
.global _start
_start:
    # 🕵️ DIAGNOSTIC: BREATHE
    li t0, 0x10000000
    li t1, 0x23 # '#'
    sb t1, 0(t0)

# Clear BSS (64-bit aligned zeroing)
    la t0, __bss_start
    la t1, __bss_end
1:  bge t0, t1, 2f
    sd zero, 0(t0)
    addi t0, t0, 8
    j 1b
2:
    fence rw, rw

    # 🔧 CRITICAL FIX: Set up stack pointer for userland
    # Stack grows down from top of 128MB userland RAM (0x90000000 - 32 bytes for alignment)
    li sp, 0x8FFFFFE0
    
    # 🔧 CRITICAL FIX: Set up global pointer for RISC-V ABI
    # Global pointer should point to .sdata section for efficient global access
    # For userland at 0x88000000, set gp to middle of address space
    .option push
    .option norelax
    la gp, __global_pointer$
    .option pop
    
    # 🕵️ DIAGNOSTIC: READY TO CALL MAIN
    li t0, 0x10000000
    li t1, 0x21 # '!'
    sb t1, 0(t0)

    # Call main(0, NULL)
    li a0, 0
    li a1, 0
    call main

    # 🕵️ DIAGNOSTIC: RETURNED FROM MAIN
    # li t0, 0x10000000
    # li t1, 0x24 # '$'
    # sb t1, 0(t0)

    # Call exit(result)
    call exit

1:  j 1b