u-boot/arch/arm/mach-imx/imx_bootaux.c
Igor Opaniuk 89038264bb mach-imx: bootaux: add dcache flushing before enabling M4
This patch fixes the issue with broken bootaux command,
when M4 binary is loaded and data cache isn't flushed
before M4 core is enabled.

Reproducing:
> tftpboot ${loadaddr} ${board_name}/hello_world.bin
> cp.b ${loadaddr} 0x7F8000 $filesize
> bootaux 0x7F8000

Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
2020-01-07 10:26:56 +01:00

103 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
*/
#include <common.h>
#include <asm/io.h>
#include <asm/mach-imx/sys_proto.h>
#include <command.h>
#include <imx_sip.h>
#include <linux/compiler.h>
#include <cpu_func.h>
int arch_auxiliary_core_up(u32 core_id, ulong boot_private_data)
{
ulong stack, pc;
if (!boot_private_data)
return -EINVAL;
stack = *(u32 *)boot_private_data;
pc = *(u32 *)(boot_private_data + 4);
printf("## Starting auxiliary core stack = 0x%08lX, pc = 0x%08lX...\n",
stack, pc);
/* Set the stack and pc to M4 bootROM */
writel(stack, M4_BOOTROM_BASE_ADDR);
writel(pc, M4_BOOTROM_BASE_ADDR + 4);
flush_dcache_all();
/* Enable M4 */
#ifdef CONFIG_IMX8M
call_imx_sip(IMX_SIP_SRC, IMX_SIP_SRC_M4_START, 0, 0, 0);
#else
clrsetbits_le32(SRC_BASE_ADDR + SRC_M4_REG_OFFSET,
SRC_M4C_NON_SCLR_RST_MASK, SRC_M4_ENABLE_MASK);
#endif
return 0;
}
int arch_auxiliary_core_check_up(u32 core_id)
{
#ifdef CONFIG_IMX8M
return call_imx_sip(IMX_SIP_SRC, IMX_SIP_SRC_M4_STARTED, 0, 0, 0);
#else
unsigned int val;
val = readl(SRC_BASE_ADDR + SRC_M4_REG_OFFSET);
if (val & SRC_M4C_NON_SCLR_RST_MASK)
return 0; /* assert in reset */
return 1;
#endif
}
/*
* To i.MX6SX and i.MX7D, the image supported by bootaux needs
* the reset vector at the head for the image, with SP and PC
* as the first two words.
*
* Per the cortex-M reference manual, the reset vector of M4 needs
* to exist at 0x0 (TCMUL). The PC and SP are the first two addresses
* of that vector. So to boot M4, the A core must build the M4's reset
* vector with getting the PC and SP from image and filling them to
* TCMUL. When M4 is kicked, it will load the PC and SP by itself.
* The TCMUL is mapped to (M4_BOOTROM_BASE_ADDR) at A core side for
* accessing the M4 TCMUL.
*/
static 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);
if (!addr)
return CMD_RET_FAILURE;
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",
""
);