How to achieve individual AMP contexts reboot？

[gege0500]

HSS v2023.02 added:
watchdog: support for rebooting individual AMP contexts

May I ask where the corresponding program is located in HSS? Is it here?

How can I test the individual AMP contexts reboot function?

[griffini]

Note: in boards/mpfs-icicle-kit/def_config, we have CONFIG_ALLOW_COLDREBOOT_ALWAYS` enabled. This will make every context reboot a full chip reboot, by default.

To test per-context reboot, ensure that CONFIG_ALLOW_COLDREBOOT_ALWAYS is disabled in your .config file in the toplevel directory. Then rebuild and reprogram the HSS to your board (make; make program). Issue a reboot from Linux in an AMP build, and it will reboot just the context associated with Linux. By default, a context is only allowed warm reboot itself.

The Kconfig option CONFIG_ALLOW_COLDREBOOT permits cold reboots for a privileged context. In order to allow a context issue a cold reboot, either CONFIG_ALLOW_COLDREBOOT_ALWAYS must enabled or the context in question must have the option the option allow-reboot: cold added to its entry in the hss-payload-generator YAML configuration file. For example:

    set-name: 'PolarFire-SoC-HSS::AmpTestImage'
    hart-entry-points: {u54_1: '0x80200000', u54_2: '0x80200000', u54_3: '0x80200000, u54_4: '0xB0000000''}
    payloads:
      test/baremetal.elf: {exec-addr: '0xB0000000', owner-hart: u54_4, priv-mode: prv_m, skip-opensbi: true}
      test/u-boot-dtb.bin:    {exec-addr: '0x80200000', owner-hart: u54_1, secondary-hart: u54_2, secondary-hart: u54_3, priv-mode: prv_s, payload-name: 'u-boot-dtb', allow-reboot: cold}

Per-context or cold reboot is implemented by catching the SBI_EXT_SRST ecall.

[Shivaraj199]

hello I am running One BM Application and generating it via payload generator, I have enable cold reboot in YAML file. but the code gets hanged in the eCALL. is there any example or documentation for ecall.

YAML file
hart-entry-points: {u54_1: '0x91800000', u54_2: '0x00000000', u54_3: '0x00000000', u54_4: '0x91C00000'}
payloads:
test/mpfs-rpmsg-master.elf: {exec-addr: '0x91800000', owner-hart: u54_1, priv-mode: prv_m, skip-opensbi: true,allow-reboot: cold}

[griffini]

Hi @Shivaraj199,

Can you provide some more details about what you are seeing?

When you say that the "code gets hanged in the eCALL", what code is making this ecall? If it is your mpfs-rpmsg-master.elf application, and it is using an ecall to access IHC functionality in the HSS, then you need to remove skip-opensbi: true in your code, and to make sure that you are not overriding the SBI Trap Handler.

[Shivaraj199]

Hello @griffini

I am running a custom freeRTOS application with just standalone master context which i hacked from amp examples running on one application core, I have removed out all the remote context hence there is no ihc.

I am am trying to achieve the function below and the code I tried to refer I pass the thwe arguments from sbi_ecall_interface.h

#define SBI_EXT_SRST_RESET 0x0

#define SBI_SRST_RESET_TYPE_SHUTDOWN 0x0
#define SBI_SRST_RESET_TYPE_COLD_REBOOT 0x1
#define SBI_SRST_RESET_TYPE_WARM_REBOOT 0x2

#define SBI_SRST_RESET_REASON_NONE 0x0
#define SBI_SRST_RESET_REASON_SYSFAIL 0x1
sbi_ecall(int ext, int fid, unsigned long arg0,
unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4,
unsigned long arg5)
{
struct sbiret ret;

register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
asm volatile ("ecall"
	      : "+r" (a0), "+r" (a1)
	      : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
	      : "memory");
ret.error = a0;
ret.value = a1;

return ret;

}

Am i missing something?

[griffini]

Are you running with OpenSBI (and with the standard HSS interrupt vector in place) ?

Or did you use skip-opensbi in the payload generator, and you have installed a custom interrupt handler? If so, then you won't easily be able to use the default ecalls to perform a context reboot.