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// SPDX-License-Identifier: GPL-2.0
#include <common.h>
#include <firmware.h>
#include <linux/sizes.h>
#include <mach/generic.h>
#include <asm/barebox-arm-head.h>
#include <asm/barebox-arm.h>
#include <mach/imx8m-ccm-regs.h>
#include <mach/iomux-mx8mq.h>
#include <soc/imx8m/ddr.h>
#include <mach/xload.h>
#include <io.h>
#include <debug_ll.h>
#include <asm/cache.h>
#include <asm/sections.h>
#include <asm/mmu.h>
#include <mach/atf.h>
#include <mach/esdctl.h>
#include "ddr.h"
extern char __dtb_imx8mq_evk_start[];
#define UART_PAD_CTRL MUX_PAD_CTRL(PAD_CTL_DSE_3P3V_45_OHM)
static void setup_uart(void)
{
imx8m_early_setup_uart_clock();
imx8mq_setup_pad(IMX8MQ_PAD_UART1_TXD__UART1_TX | UART_PAD_CTRL);
imx8m_uart_setup_ll();
putc_ll('>');
}
/*
* Power-on execution flow of start_nxp_imx8mq_evk() might not be
* obvious for a very first read, so here's, hopefully helpful,
* summary:
*
* 1. MaskROM uploads PBL into OCRAM and that's where this function is
* executed for the first time. At entry the exception level is EL3.
*
* 2. DDR is initialized and the image is loaded from storage into DRAM. The PBL
* part is copied from OCRAM to the TF-A return address in DRAM.
*
* 3. TF-A is executed and exits into the PBL code in DRAM. TF-A has taken us
* from EL3 to EL2.
*
* 4. Standard barebox boot flow continues
*/
static __noreturn noinline void nxp_imx8mq_evk_start(void)
{
if (IS_ENABLED(CONFIG_DEBUG_LL))
setup_uart();
/*
* If we are in EL3 we are running for the first time and need to
* initialize the DRAM and run TF-A (BL31). The TF-A will then jump
* to DRAM in EL2.
*/
if (current_el() == 3) {
enum bootsource src = BOOTSOURCE_UNKNOWN;
int instance = BOOTSOURCE_INSTANCE_UNKNOWN;
int ret = -ENOTSUPP;
size_t bl31_size;
const u8 *bl31;
ddr_init();
/*
* On completion the TF-A will jump to MX8MQ_ATF_BL33_BASE_ADDR
* in EL2. Copy the image there, but replace the PBL part of
* that image with ourselves. On a high assurance boot only the
* currently running code is validated and contains the checksum
* for the piggy data, so we need to ensure that we are running
* the same code in DRAM.
*/
imx8mq_get_boot_source(&src, &instance);
if (src == BOOTSOURCE_MMC)
ret = imx8m_esdhc_load_image(instance, false);
BUG_ON(ret);
memcpy((void *)MX8MQ_ATF_BL33_BASE_ADDR,
__image_start, barebox_pbl_size);
get_builtin_firmware(imx8mq_bl31_bin, &bl31, &bl31_size);
imx8mq_atf_load_bl31(bl31, bl31_size);
/* not reached */
}
/*
* Standard entry we hit once we initialized both DDR and ATF
*/
imx8mq_barebox_entry(__dtb_imx8mq_evk_start);
}
ENTRY_FUNCTION(start_nxp_imx8mq_evk, r0, r1, r2)
{
imx8mq_cpu_lowlevel_init();
relocate_to_current_adr();
setup_c();
nxp_imx8mq_evk_start();
}
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