u-boot/arch/arm/lib/stack.c

/*
 * Copyright (c) 2015 Andreas Bießmann <andreas.devel@googlemail.com>
 *
 * Copyright (c) 2011 The Chromium OS Authors.
 * (C) Copyright 2002-2006
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Marius Groeger <mgroeger@sysgo.de>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>

DECLARE_GLOBAL_DATA_PTR;

int arch_reserve_stacks(void)
{
#ifdef CONFIG_SPL_BUILD
	gd->start_addr_sp -= 128;	/* leave 32 words for abort-stack */
	gd->irq_sp = gd->start_addr_sp;
#else
	/* setup stack pointer for exceptions */
	gd->irq_sp = gd->start_addr_sp;

# if !defined(CONFIG_ARM64)
#  ifdef CONFIG_USE_IRQ
	gd->start_addr_sp -= (CONFIG_STACKSIZE_IRQ + CONFIG_STACKSIZE_FIQ);
	debug("Reserving %zu Bytes for IRQ stack at: %08lx\n",
	      CONFIG_STACKSIZE_IRQ + CONFIG_STACKSIZE_FIQ, gd->start_addr_sp);

	/* 8-byte alignment for ARM ABI compliance */
	gd->start_addr_sp &= ~0x07;
#  endif
	/* leave 3 words for abort-stack, plus 1 for alignment */
	gd->start_addr_sp -= 16;
# endif
#endif

	return 0;
}