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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 Christian Hemp
*/
#include <common.h>
#include <firmware.h>
#include <linux/sizes.h>
#include <mach/imx/generic.h>
#include <asm/barebox-arm-head.h>
#include <asm/barebox-arm.h>
#include <mach/imx/imx8m-ccm-regs.h>
#include <mach/imx/iomux-mx8mq.h>
#include <soc/imx8m/ddr.h>
#include <mach/imx/xload.h>
#include <io.h>
#include <debug_ll.h>
#include <mach/imx/debug_ll.h>
#include <asm/cache.h>
#include <asm/sections.h>
#include <asm/mmu.h>
#include <mach/imx/atf.h>
#include <mach/imx/esdctl.h>
#include "ddr.h"
extern char __dtb_z_imx8mq_phytec_phycore_som_start[];
#define UART_PAD_CTRL MUX_PAD_CTRL(PAD_CTL_DSE_3P3V_45_OHM)
static void setup_uart(void)
{
void __iomem *uart = IOMEM(MX8M_UART1_BASE_ADDR);
imx8m_early_setup_uart_clock();
imx8mq_setup_pad(IMX8MQ_PAD_UART1_TXD__UART1_TX | UART_PAD_CTRL);
imx8m_uart_setup(uart);
pbl_set_putc(imx_uart_putc, uart);
putc_ll('>');
}
static __noreturn noinline void phytec_phycore_imx8mq_start(void)
{
setup_uart();
if (get_pc() < MX8MQ_DDR_CSD1_BASE_ADDR) {
/*
* We assume that we were just loaded by MaskROM into
* SRAM if we are not running from DDR. We also assume
* that means DDR needs to be initialized for the
* first time.
*/
ddr_init();
}
/*
* Straight from the power-on we are at EL3, so the following
* code _will_ load and jump to ATF.
*
* However when we are re-executed upon exit from ATF's
* initialization routine, it is EL2 which means we'll skip
* loadting ATF blob again
*/
if (current_el() == 3)
imx8mq_load_and_start_image_via_tfa();
/*
* Standard entry we hit once we initialized both DDR and ATF
*/
imx8mq_barebox_entry(__dtb_z_imx8mq_phytec_phycore_som_start);
}
/*
* Power-on execution flow of start_phytec_phycore_imx8mq() 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
*
* 2. DDR is initialized and full i.MX image is loaded to the
* beginning of RAM
*
* 3. start_phytec_phycore_imx8mq, now in RAM, is executed again
*
* 4. BL31 blob is uploaded to OCRAM and the control is transfer to it
*
* 5. BL31 exits EL3 into EL2 at address MX8M_ATF_BL33_BASE_ADDR,
* executing start_phytec_phycore_imx8mq() the third time
*
* 6. Standard barebox boot flow continues
*/
ENTRY_FUNCTION(start_phytec_phycore_imx8mq, r0, r1, r2)
{
imx8mq_cpu_lowlevel_init();
relocate_to_current_adr();
setup_c();
phytec_phycore_imx8mq_start();
}
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