linux_dsm_epyc7002/arch/csky/kernel/head.S
Guo Ren 9143a9359d csky: Kernel booting
This patch add boot code. Thx boot params is all in dtb and it's
the only way to let kernel get bootloader param information.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2018-10-25 23:36:19 +08:00

78 lines
1.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/page.h>
#include <abi/entry.h>
__HEAD
ENTRY(_start)
/* set super user mode */
lrw a3, DEFAULT_PSR_VALUE
mtcr a3, psr
psrset ee
SETUP_MMU a3
/* set stack point */
lrw a3, init_thread_union + THREAD_SIZE
mov sp, a3
jmpi csky_start
END(_start)
#ifdef CONFIG_SMP
.align 10
ENTRY(_start_smp_secondary)
/* Invalid I/Dcache BTB BHT */
movi a3, 7
lsli a3, 16
addi a3, (1<<4) | 3
mtcr a3, cr17
tlbi.alls
/* setup PAGEMASK */
movi a3, 0
mtcr a3, cr<6, 15>
/* setup MEL0/MEL1 */
grs a0, _start_smp_pc
_start_smp_pc:
bmaski a1, 13
andn a0, a1
movi a1, 0x00000006
movi a2, 0x00001006
or a1, a0
or a2, a0
mtcr a1, cr<2, 15>
mtcr a2, cr<3, 15>
/* setup MEH */
mtcr a0, cr<4, 15>
/* write TLB */
bgeni a3, 28
mtcr a3, cr<8, 15>
SETUP_MMU a3
/* enable MMU */
movi a3, 1
mtcr a3, cr18
jmpi _goto_mmu_on
_goto_mmu_on:
lrw a3, DEFAULT_PSR_VALUE
mtcr a3, psr
psrset ee
/* set stack point */
lrw a3, secondary_stack
ld.w a3, (a3, 0)
mov sp, a3
jmpi csky_start_secondary
END(_start_smp_secondary)
#endif