linux_dsm_epyc7002/arch/riscv/kernel/vmlinux.lds.S
Damien Le Moal 335b139057
riscv: Add SOC early init support
Add a mechanism for early SoC initialization for platforms that need
additional hardware initialization not possible through the regular
device tree and drivers mechanism. With this, a SoC specific
initialization function can be called very early, before DTB parsing
is done by parse_dtb() in Linux RISC-V kernel setup code.

This can be very useful for early hardware initialization for No-MMU
kernels booted directly in M-mode because it is quite likely that no
other booting stage exist prior to the No-MMU kernel.

Example use of a SoC early initialization is as follows:

static void vendor_abc_early_init(const void *fdt)
{
	/*
	 * some early init code here that can use simple matches
	 * against the flat device tree file.
	 */
}
SOC_EARLY_INIT_DECLARE("vendor,abc", abc_early_init);

This early initialization function is executed only if the flat device
tree for the board has a 'compatible = "vendor,abc"' entry;

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-03 10:46:43 -07:00

98 lines
1.5 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
*/
#define LOAD_OFFSET PAGE_OFFSET
#include <asm/vmlinux.lds.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/set_memory.h>
#include <linux/sizes.h>
OUTPUT_ARCH(riscv)
ENTRY(_start)
jiffies = jiffies_64;
SECTIONS
{
/* Beginning of code and text segment */
. = LOAD_OFFSET;
_start = .;
HEAD_TEXT_SECTION
. = ALIGN(PAGE_SIZE);
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
INIT_DATA_SECTION(16)
. = ALIGN(8);
__soc_early_init_table : {
__soc_early_init_table_start = .;
KEEP(*(__soc_early_init_table))
__soc_early_init_table_end = .;
}
/* we have to discard exit text and such at runtime, not link time */
.exit.text :
{
EXIT_TEXT
}
.exit.data :
{
EXIT_DATA
}
PERCPU_SECTION(L1_CACHE_BYTES)
__init_end = .;
. = ALIGN(SECTION_ALIGN);
.text : {
_text = .;
_stext = .;
TEXT_TEXT
SCHED_TEXT
CPUIDLE_TEXT
LOCK_TEXT
KPROBES_TEXT
ENTRY_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.fixup)
_etext = .;
}
/* Start of data section */
_sdata = .;
RO_DATA(SECTION_ALIGN)
.srodata : {
*(.srodata*)
}
EXCEPTION_TABLE(0x10)
. = ALIGN(SECTION_ALIGN);
_data = .;
RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
.sdata : {
__global_pointer$ = . + 0x800;
*(.sdata*)
/* End of data section */
_edata = .;
}
BSS_SECTION(PAGE_SIZE, PAGE_SIZE, 0)
.rel.dyn : {
*(.rel.dyn*)
}
_end = .;
STABS_DEBUG
DWARF_DEBUG
DISCARDS
}