u-boot/arch/arm/mach-imx/imx_bootaux.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
*/
#include <common.h>
#include <log.h>
#include <asm/io.h>
#include <asm/mach-imx/sys_proto.h>
#include <command.h>
#include <elf.h>
#include <imx_sip.h>
#include <linux/arm-smccc.h>
#include <linux/compiler.h>
#include <cpu_func.h>
#ifndef CONFIG_IMX8M
const __weak struct rproc_att hostmap[] = { };
static const struct rproc_att *get_host_mapping(unsigned long auxcore)
{
const struct rproc_att *mmap = hostmap;
while (mmap && mmap->size) {
if (mmap->da <= auxcore &&
mmap->da + mmap->size > auxcore)
return mmap;
mmap++;
}
return NULL;
}
/*
* A very simple elf loader for the auxilary core, assumes the image
* is valid, returns the entry point address.
* Translates load addresses in the elf file to the U-Boot address space.
*/
static unsigned long load_elf_image_m_core_phdr(unsigned long addr)
{
Elf32_Ehdr *ehdr; /* ELF header structure pointer */
Elf32_Phdr *phdr; /* Program header structure pointer */
int i;
ehdr = (Elf32_Ehdr *)addr;
phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);
/* Load each program header */
for (i = 0; i < ehdr->e_phnum; ++i, ++phdr) {
const struct rproc_att *mmap = get_host_mapping(phdr->p_paddr);
void *dst, *src;
if (phdr->p_type != PT_LOAD)
continue;
if (!mmap) {
printf("Invalid aux core address: %08x",
phdr->p_paddr);
return 0;
}
dst = (void *)(phdr->p_paddr - mmap->da) + mmap->sa;
src = (void *)addr + phdr->p_offset;
debug("Loading phdr %i to 0x%p (%i bytes)\n",
i, dst, phdr->p_filesz);
if (phdr->p_filesz)
memcpy(dst, src, phdr->p_filesz);
if (phdr->p_filesz != phdr->p_memsz)
memset(dst + phdr->p_filesz, 0x00,
phdr->p_memsz - phdr->p_filesz);
flush_cache((unsigned long)dst &
~(CONFIG_SYS_CACHELINE_SIZE - 1),
ALIGN(phdr->p_filesz, CONFIG_SYS_CACHELINE_SIZE));
}
return ehdr->e_entry;
}
#endif
int arch_auxiliary_core_up(u32 core_id, ulong addr)
{
ulong stack, pc;
if (!addr)
return -EINVAL;
#ifdef CONFIG_IMX8M
stack = *(u32 *)addr;
pc = *(u32 *)(addr + 4);
#else
/*
* handling ELF64 binaries
* isn't supported yet.
*/
if (valid_elf_image(addr)) {
stack = 0x0;
pc = load_elf_image_m_core_phdr(addr);
if (!pc)
return CMD_RET_FAILURE;
} else {
/*
* Assume binary file with vector table at the beginning.
* Cortex-M4 vector tables start with the stack pointer (SP)
* and reset vector (initial PC).
*/
stack = *(u32 *)addr;
pc = *(u32 *)(addr + 4);
}
#endif
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
arm_smccc_smc(IMX_SIP_SRC, IMX_SIP_SRC_M4_START, 0, 0,
0, 0, 0, 0, NULL);
#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
struct arm_smccc_res res;
arm_smccc_smc(IMX_SIP_SRC, IMX_SIP_SRC_M4_STARTED, 0, 0,
0, 0, 0, 0, &res);
return res.a0;
#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(struct cmd_tbl *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 = hextoul(argv[1], NULL);
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",
""
);