u-boot/arch/mips/mach-octeon/lowlevel_init.S
Stefan Roese e9609dc38b mips: octeon: use mips_mach_early_init() to copy to L2 cache
This patch adds the code to copy itself from bootrom location to a
different location (TEXT_BASE) to the Octeon platform. Its used in
this case to copy the complete U-Boot image into L2 cache, which
greatly improves the bootup time - especially in regard to the
very long and complex DDR4 init code.

The Kconfig symbol CONFIG_MIPS_MACH_EARLY_INIT is enabled with this
patch for Octeon.

Signed-off-by: Stefan Roese <sr@denx.de>
2020-07-18 15:47:50 +02:00

69 lines
1.4 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Stefan Roese <sr@denx.de>
*/
#include <config.h>
#include <asm-offsets.h>
#include <asm/cacheops.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/asm.h>
.set noreorder
LEAF(lowlevel_init)
jr ra
nop
END(lowlevel_init)
LEAF(mips_mach_early_init)
move s0, ra
bal __dummy
nop
__dummy:
/* Get the actual address that we are running at */
PTR_LA a7, __dummy
dsubu t3, ra, a7 /* t3 now has reloc offset */
PTR_LA t1, _start
daddu t0, t1, t3 /* t0 now has actual address of _start */
/* Calculate end address of copy loop */
PTR_LA t2, _end
daddiu t2, t2, 0x4000 /* Increase size to include appended DTB */
daddiu t2, t2, 127
ins t2, zero, 0, 7 /* Round up to cache line for memcpy */
/* Copy ourself to the L2 cache from flash, 32 bytes at a time */
1:
ld a0, 0(t0)
ld a1, 8(t0)
ld a2, 16(t0)
ld a3, 24(t0)
sd a0, 0(t1)
sd a1, 8(t1)
sd a2, 16(t1)
sd a3, 24(t1)
addiu t0, 32
addiu t1, 32
bne t1, t2, 1b
nop
sync
/*
* Return to start.S now running from TEXT_BASE, which points
* to DRAM address space, which effectively is L2 cache now.
* This speeds up the init process extremely, especially the
* DDR init code.
*/
dsubu s0, s0, t3 /* Fixup return address with reloc offset */
jr.hb s0 /* Jump back with hazard barrier */
nop
END(mips_mach_early_init)