[U-Boot] [PATCH 06/11] imx: imx-common: introduce boot auxiliary core

[Peng Fan]

Hi Stefan,
On Wed, Jan 06, 2016 at 10:59:17PM -0800, Stefan Agner wrote:
>On 2016-01-04 21:56, Peng Fan wrote:
>> From: Peng Fan <peng.fan at nxp.com>
>> 
>> To boot a auxiliary core in asymmetric multicore system, introduce the
>> new command "bootaux" to do it. Example of boot auxliary core from
>> 0x70000000 where stores the boot head information that should be
>> parsed by auxiliary core, "bootaux 0x70000000".
>
>This reminds me of a question which was nagging me lately:
>Is the M4 core of SoloX/MX7 running a boot ROM? Or who/what is "parsing
>the boot head information"?

There is no bootrom for m4 core. The bootimage for M4 contains stack
info and pc info. bootaux command will use the info extracted from bootimage.

See the following code:
"
int arch_auxiliary_core_up(u32 core_id, u32 boot_private_data)
{
	struct src *src_reg;
	u32 stack, pc;

	if (!boot_private_data)
		return 1;

	stack = *(u32 *)boot_private_data;
	pc = *(u32 *)(boot_private_data + 4);

	/* Set the stack and pc to M4 bootROM */
	writel(stack, M4_BOOTROM_BASE_ADDR);
	writel(pc, M4_BOOTROM_BASE_ADDR + 4);

	/* Enable M4 */
	src_reg = (struct src *)SRC_BASE_ADDR;
	setbits_le32(&src_reg->scr, 0x00400000);
	clrbits_le32(&src_reg->scr, 0x00000010);

	return 0;
}

"

>
>
>> Introduce Kconfig option IMX_BOOTAUX.
>> 
>> Signed-off-by: Ye.Li <ye.li at nxp.com>
>> Signed-off-by: Peng Fan <peng.fan at nxp.com>
>> ---
>>  arch/arm/imx-common/Kconfig       |  6 ++++
>>  arch/arm/imx-common/Makefile      |  1 +
>>  arch/arm/imx-common/imx_bootaux.c | 59 +++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 66 insertions(+)
>>  create mode 100644 arch/arm/imx-common/imx_bootaux.c
>> 
>> diff --git a/arch/arm/imx-common/Kconfig b/arch/arm/imx-common/Kconfig
>> index c4f48bb..1b7da5a 100644
>> --- a/arch/arm/imx-common/Kconfig
>> +++ b/arch/arm/imx-common/Kconfig
>> @@ -11,3 +11,9 @@ config IMX_RDC
>>  	  i.MX Resource domain controller is used to assign masters
>>  	  and peripherals to differet domains. This can be used to
>>  	  isolate resources.
>> +
>> +config IMX_BOOTAUX
>> +	bool "Support boot auxiliary core"
>> +	depends on ARCH_MX7 || ARCH_MX6
>> +	help
>> +	  bootaux [addr] to boot auxiliary core.
>> diff --git a/arch/arm/imx-common/Makefile b/arch/arm/imx-common/Makefile
>> index 568f41c..30e66ba 100644
>> --- a/arch/arm/imx-common/Makefile
>> +++ b/arch/arm/imx-common/Makefile
>> @@ -28,6 +28,7 @@ obj-y 	+= cache.o init.o
>>  obj-$(CONFIG_CMD_SATA) += sata.o
>>  obj-$(CONFIG_IMX_VIDEO_SKIP) += video.o
>>  obj-$(CONFIG_IMX_RDC) += rdc-sema.o
>> +obj-$(CONFIG_IMX_BOOTAUX) += imx_bootaux.o
>>  obj-$(CONFIG_SECURE_BOOT)    += hab.o
>>  endif
>>  ifeq ($(SOC),$(filter $(SOC),vf610))
>> diff --git a/arch/arm/imx-common/imx_bootaux.c
>> b/arch/arm/imx-common/imx_bootaux.c
>> new file mode 100644
>> index 0000000..da424a7
>> --- /dev/null
>> +++ b/arch/arm/imx-common/imx_bootaux.c
>> @@ -0,0 +1,59 @@
>> +/*
>> + * Copyright (C) 2016 Freescale Semiconductor, Inc.
>> + *
>> + * SPDX-License-Identifier:	GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <command.h>
>> +
>> +/* Allow for arch specific config before we boot */
>> +static int __arch_auxiliary_core_up(u32 core_id, u32 boot_private_data)
>> +{
>> +	/* please define platform specific arch_auxiliary_core_up() */
>> +	return CMD_RET_FAILURE;
>> +}
>> +
>> +int arch_auxiliary_core_up(u32 core_id, u32 boot_private_data)
>> +	__attribute__((weak, alias("__arch_auxiliary_core_up")));
>> +
>> +/* Allow for arch specific config before we boot */
>> +static int __arch_auxiliary_core_check_up(u32 core_id)
>> +{
>> +	/* please define platform specific arch_auxiliary_core_check_up() */
>> +	return 0;
>> +}
>> +
>> +int arch_auxiliary_core_check_up(u32 core_id)
>> +	__attribute__((weak, alias("__arch_auxiliary_core_check_up")));
>> +
>> +int do_bootaux(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>> +{
>> +	ulong addr;
>> +	int ret, up;
>> +
>> +	if (argc < 2)
>> +		return CMD_RET_USAGE;
>> +
>> +	up = arch_auxiliary_core_check_up(0);
>> +	if (up) {
>> +		printf("## Auxiliary core is already up\n");
>> +		return CMD_RET_SUCCESS;
>> +	}
>> +
>> +	addr = simple_strtoul(argv[1], NULL, 16);
>> +
>> +	printf("## Starting auxiliary core at 0x%08lX ...\n", addr);
>> +
>> +	ret = arch_auxiliary_core_up(0, addr);
>> +	if (ret)
>> +		return CMD_RET_FAILURE;
>> +
>> +	return CMD_RET_SUCCESS;
>> +}
>> +
>> +U_BOOT_CMD(
>> +	bootaux, CONFIG_SYS_MAXARGS, 1,	do_bootaux,
>> +	"Start auxiliary core",
>
>What kind of image are supported by the bootaux command? Afaik, this is
>some special/binary only format right?

Yeah. I just got the image from our rtos team, I do not have detail
info about the format.

>
>Probably another discussion, but before polluting the command namespace:
>Is that what we generally want?

Hmm, bootaux invokes
arch_auxiliary_core_check_up
arch_auxiliary_core_u

And arch code takes the responsibility to implement these two functions.

We try to make this common, but not sure whether this is ok for other SoCs.
So I move the command to arch/arm/imx-common

Thanks,
Peng.

>
>--
>Stefan
>
>> +	""
>> +);