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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <common.h>
#include <linux/sizes.h>
#include <mach/generic.h>
#include <asm/barebox-arm-head.h>
#include <asm/barebox-arm.h>
#include <mach/imx8-ccm-regs.h>
#include <mach/iomux-mx8.h>
#include <mach/imx8-ddrc.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)
{
void __iomem *iomux = IOMEM(MX8MQ_IOMUXC_BASE_ADDR);
void __iomem *ccm = IOMEM(MX8MQ_CCM_BASE_ADDR);
writel(CCM_CCGR_SETTINGn_NEEDED(0),
ccm + CCM_CCGRn_CLR(CCM_CCGR_UART1));
writel(CCM_TARGET_ROOTn_ENABLE | UART1_CLK_ROOT__25M_REF_CLK,
ccm + CCM_TARGET_ROOTn(UART1_CLK_ROOT));
writel(CCM_CCGR_SETTINGn_NEEDED(0),
ccm + CCM_CCGRn_SET(CCM_CCGR_UART1));
imx_setup_pad(iomux, IMX8MQ_PAD_UART1_TXD__UART1_TX | UART_PAD_CTRL);
imx8_uart_setup_ll();
putc_ll('>');
}
static void nxp_imx8mq_evk_sram_setup(void)
{
enum bootsource src = BOOTSOURCE_UNKNOWN;
int instance = BOOTSOURCE_INSTANCE_UNKNOWN;
int ret = -ENOTSUPP;
ddr_init();
imx8_get_boot_source(&src, &instance);
if (src == BOOTSOURCE_MMC)
ret = imx8_esdhc_start_image(instance);
BUG_ON(ret);
}
/*
* 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
*
* 2. DDR is initialized and full i.MX image is loaded to the
* beginning of RAM
*
* 3. start_nxp_imx8mq_evk, 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 MX8MQ_ATF_BL33_BASE_ADDR,
* executing start_nxp_imx8mq_evk() the third time
*
* 6. Standard barebox boot flow continues
*/
ENTRY_FUNCTION(start_nxp_imx8mq_evk, r0, r1, r2)
{
arm_cpu_lowlevel_init();
if (IS_ENABLED(CONFIG_DEBUG_LL))
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.
*/
nxp_imx8mq_evk_sram_setup();
}
/*
* 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) {
const u8 *bl31;
size_t bl31_size;
get_builtin_firmware(imx_imx8m_bl31_bin, &bl31, &bl31_size);
imx8mq_atf_load_bl31(bl31, bl31_size);
}
/*
* Standard entry we hit once we initialized both DDR and ATF
*/
imx8mq_barebox_entry(__dtb_imx8mq_evk_start);
}
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