# boot.S (RISC-V rv64) — the minimal asm entry.
# QEMU 'virt' with -bios none enters here at 0x80000000 in M-mode,
# all harts. We park every hart but hart 0, set a stack, clear .bss,
# and jump to kmain(). This is the irreducible asm part for this arch.

	.section .text.boot
	.globl _start
_start:
	# Only hart 0 continues; others wait forever (WFI loop).
	csrr	t0, mhartid
	bnez	t0, park

	# Set up the stack (defined in the linker script).
	la	sp, _stack_top

	# Zero the .bss section: [__bss_start, __bss_end).
	la	t0, __bss_start
	la	t1, __bss_end
1:	bgeu	t0, t1, 2f
	sd	zero, (t0)
	addi	t0, t0, 8
	j	1b
2:
	call	kmain

park:
	wfi
	j	park