Hi Yanyan,
1. It doesn't set the NS bit to 1 in SCR(I just want it to return without
do anything). The arm_monitor_vector and the smc_handler():
arm_monitor_vector:
ldr pc, [pc, #28]
ldr pc, [pc, #24]
ldr pc, =smc_handler
ldr pc, [pc, #16]
ldr pc, [pc, #12]
ldr pc, [pc, #8]
ldr pc, [pc, #4]
ldr pc, [pc, #0]
smc_handler:
movs pc, lr
2. I didn't do any extra work other than the boot log:
..........
ELF-loader started on CPU: ARM Ltd. Cortex-A9 r2p10
paddr=[20000000..203fbfff]
ELF-loading image 'kernel'
paddr=[10000000..10026fff]
vaddr=[e0000000..e0026fff]
virt_entry=e0000000
ELF-loading image 'sel4test-driver'
paddr=[10027000..10500fff]
vaddr=[8000..4e1fff]
virt_entry=25a6c
Enabling MMU and paging
Jumping to kernel-image entry point...
3. The initialization operations in platform_init.c:
set sp:
#define MONITOR_MODE (0x16)
#define MON_VECTOR_START (0x11000000)
#define VECTOR_BASE 0x11000000
#define STACK_TOP (VECTOR_BASE + (1 << 12) - 0x10)
asm volatile ( "mrs r1, cpsr\n\t"
"cps %0\n\t"
"isb\n"
"mov sp, %1\n\t"
"msr cpsr, r1\n\t"
::"I"(MONITOR_MODE),"r"(STACK_TOP));
copy monitor mode vector to MON_VECTOR_START and write into MVBAR:
uint32_t size = arm_monitor_vector_end - arm_monitor_vector;
printf("Copy monitor mode vector from %x to %x size %x\n",
(arm_monitor_vector), MON_VECTOR_START, size);
memcpy((void *)MON_VECTOR_START, (void *)(arm_monitor_vector), size);
asm volatile ("dmb\n isb\n");
asm volatile ("mcr p15, 0, %0, c12, c0, 1"::"r"(MON_VECTOR_START));
I enter into SVC mode by software interrupt and call the function smc():
asm (".arch_extension sec\n");
asm volatile ("stmfd sp!, {r3-r11, lr}\n\t"
"dsb\n"
"smc #0\n"
"ldmfd sp!, {r3-r11, pc}");
and then the problem arises.
Thank you,
Dongxu Ji
<Yanyan.Shen(a)data61.csiro.au> 于2018年8月28日周二 下午8:30写道：
> Hi,
>
> The smc_handle() in monitor.S, it does nothing but "movs pc, lr".
>
> Does it set the NS bit to 1 in SCR?
>
> Also, what did you do to ensure that 0x11000000 is not used by the kernel?
>
> Could you share the code (if possible) so that I could better understand
> the problem.
>
> Regards,
> Yanyan
>
>
> ------------------------------
> *From:* Devel <devel-bounces(a)sel4.systems> on behalf of 冀东旭 <
> jidongxu1993(a)gmail.com>
> *Sent:* Tuesday, August 28, 2018 1:02 PM
> *To:* devel(a)sel4.systems
> *Subject:* [seL4] SMC in seL4
>
> Hello,
>
> I'm porting sel4 to imx6q sabrelite as the trusted OS in trustzone. I initialize the monitor mode by setting the sp to STACK_TOP and copying arm_monitor_vector to MON_VECTOR_START according to the functions "install_monitor_hook()" and "switch_to_mon_mode()" in "platform_init.c".
>
> #define VECTOR_BASE 0x11000000(addr is not used by the seL4 kernel)
>
> #define STACK_TOP (VECTOR_BASE + (1 << 12) - 0x10)
>
> #define MON_VECTOR_START 0x11000000(The VECTOR_BASE is the same as MON_VECTOR_START)
>
> The smc_handle() in monitor.S, it does nothing but "movs pc, lr". After calling smc in SVC mode, it hangs without any log. If I comment the "smc #0", it can return the caller successfully in usr mode.
>
> stmfd sp!, {r3-r11, lr}
> dsb
> smc #0
> ldmfd sp!, {r3-r11, pc}
>
> Is the sp in monitor mode appropriate? Or I need to do something else in initialization operations? What's wrong with it? Do you have any ideas?
>
> Thank you!
>
> Dongxu Ji
>
>
