include/linker/intlist.ld

/*
 * Copyright (c) 2017 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/* This creates a special section which is not included by the final binary,
 * instead it is consumed by the gen_isr_tables.py script.
 *
 * What we create here is a data structure:
 *
 * struct {
 *	void *spurious_irq_handler;
 *	void *sw_irq_handler;
 *	uint32_t num_isrs;
 *	uint32_t num_vectors;
 *	struct _isr_list isrs[];  <- of size num_isrs
 * }
 *
 * Which indicates the memory address of the spurious IRQ handler and the
 * number of isrs that were defined, the total number of IRQ lines in the
 * system,  followed by an appropriate number of instances of
 * struct _isr_list. See include/sw_isr_table.h
 *
 * You will need to declare a bogus memory region for IDT_LIST. It doesn't
 * matter where this region goes as it is stripped from the final ELF image.
 * The address doesn't even have to be valid on the target. However, it
 * shouldn't overlap any other regions. On most arches the following should be
 * fine:
 *
 * MEMORY {
 *	.. other regions ..
 *	IDT_LIST        : ORIGIN = 0xfffff7ff, LENGTH = 2K
 * }
 */

/* We don't set NOLOAD here, as objcopy will not let us extract the intList
 * section into a file if we do so; the resulting file is 0 bytes. We do so
 * with objcopy in Makefile.gen_isr_tables after we have extracted the
 * information we need.
 */

SECTION_PROLOGUE(.intList,,)
{
	KEEP(*(.irq_info))
	LONG((__INT_LIST_END__ - __INT_LIST_START__) / __ISR_LIST_SIZEOF)
	__INT_LIST_START__ = .;
	KEEP(*(.intList))
	__INT_LIST_END__ = .;
} GROUP_LINK_IN(IDT_LIST)