xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

csky: Support vmlinux bootup with MMU off

Browse Source 
Modify SETUP_MMU macro to fit on both MMU-on or MMU-off enviornment
and vmlinux could bootup from MMU off enviornment for some cases.

Unify the style of _start and _start_smp_secondary in head.S to make
head.S looks more concise and easy to understand.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Guo Ren
2019-04-12 19:08:34 +08:00
parent b4bf274198
commit 205353fa06
4 changed files with 88 additions and 83 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
arch/csky/kernel/head.S
View File

@@ -7,16 +7,11 @@
__HEAD
ENTRY(_start)
/* set super user mode */
lrw a3, DEFAULT_PSR_VALUE
mtcr a3, psr
psrset ee
SETUP_MMU a3
SETUP_MMU
/* set stack point */
lrw a3, init_thread_union + THREAD_SIZE
mov sp, a3
lrw r6, init_thread_union + THREAD_SIZE
mov sp, r6
jmpi csky_start
END(_start)
@@ -24,53 +19,12 @@ 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
SETUP_MMU
/* set stack point */
lrw a3, secondary_stack
ld.w a3, (a3, 0)
mov sp, a3
lrw r6, secondary_stack
ld.w r6, (r6, 0)
mov sp, r6
jmpi csky_start_secondary
END(_start_smp_secondary)

7
arch/csky/kernel/setup.c
View File

@@ -145,7 +145,8 @@ void __init setup_arch(char **cmdline_p)
unsigned long phys_offset;
EXPORT_SYMBOL(phys_offset);
asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
asmlinkage __visible void __init csky_start(unsigned int unused,
void *dtb_start)
{
/* Clean up bss section */
memset(__bss_start, 0, __bss_stop - __bss_start);
@@ -155,10 +156,10 @@ asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
pre_trap_init();
pre_mmu_init();
if (param == NULL)
if (dtb_start == NULL)
early_init_dt_scan(__dtb_start);
else
early_init_dt_scan(param);
early_init_dt_scan(dtb_start);
start_kernel();