Am Montag, den 05.08.2019, 11:23 +0200 schrieb Rouven Czerwinski:
> Rework the evk boot flow to use the new piggydata load function and
> install a trampoline for the TF-A setup. This allows the PBL boot
> process to stay in SRAM up until the verification of the piggydata is
> done and main barebox can be loaded.
>
> The trampoline loads 4 bytes right after the trampoline, we copy the
> runtime offset there so the trampoline jumps back into the SRAM PBL.
>
> > Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
> ---
> arch/arm/boards/nxp-imx8mq-evk/Makefile | 4 +-
> arch/arm/boards/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg | 1 +-
> arch/arm/boards/nxp-imx8mq-evk/lowlevel.c | 83 +++----
> arch/arm/boards/nxp-imx8mq-evk/trampoline.S | 11 +-
> images/Makefile.imx | 3 +-
> 5 files changed, 60 insertions(+), 42 deletions(-)
> create mode 100644 arch/arm/boards/nxp-imx8mq-evk/trampoline.S
>
> diff --git a/arch/arm/boards/nxp-imx8mq-evk/Makefile b/arch/arm/boards/nxp-imx8mq-evk/Makefile
> index 0546b0b..7907de4 100644
> --- a/arch/arm/boards/nxp-imx8mq-evk/Makefile
> +++ b/arch/arm/boards/nxp-imx8mq-evk/Makefile
> @@ -1,4 +1,2 @@
> obj-y += board.o
> -lwl-y += lowlevel.o ddr_init.o ddrphy_train.o
> -
> -
> +lwl-y += lowlevel.o ddr_init.o ddrphy_train.o trampoline.o
> diff --git a/arch/arm/boards/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg b/arch/arm/boards/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg
> index aff8321..11463fe 100644
> --- a/arch/arm/boards/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg
> +++ b/arch/arm/boards/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg
> @@ -3,3 +3,4 @@ soc imx8mq
> loadaddr 0x007E1000
> max_load_size 0x3F000
> dcdofs 0x400
> +#include <mach/habv4-imx8-gencsf.h>
> diff --git a/arch/arm/boards/nxp-imx8mq-evk/lowlevel.c b/arch/arm/boards/nxp-imx8mq-evk/lowlevel.c
> index 6451e5d..2e23a4c 100644
> --- a/arch/arm/boards/nxp-imx8mq-evk/lowlevel.c
> +++ b/arch/arm/boards/nxp-imx8mq-evk/lowlevel.c
> @@ -53,20 +53,29 @@ static void setup_uart(void)
>
> 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);
> +extern unsigned char trampoline_start[];
> +extern unsigned char trampoline_end[];
>
> > - if (src == BOOTSOURCE_MMC)
> > - ret = imx8_esdhc_start_image(instance);
> +static void nxp_imx8mq_evk_install_tfa_trampoline(void)
> +{
> > + unsigned int tramp_len;
> > + unsigned int offset;
> > + /*
> > + * Create a trampoline which is places in DRAM and calls back into the
> > + * PBL entry function found in the TCRAM. Register x0 is set to 1 to
> > + * indicate that DRAM setup was already run.
> > + */
> > + tramp_len = (void *)trampoline_end - (void *)trampoline_start;
> > + memcpy((void *)MX8MQ_ATF_BL33_BASE_ADDR, (void *)trampoline_start,
> > + tramp_len);
>
> > - BUG_ON(ret);
> > + offset = get_runtime_offset();
> > + memcpy((void *)MX8MQ_ATF_BL33_BASE_ADDR + tramp_len, &offset,
> > + sizeof(offset));
> }
> -
> /*
> * Power-on execution flow of start_nxp_imx8mq_evk() might not be
> * obvious for a very first read, so here's, hopefully helpful,
> @@ -75,53 +84,53 @@ static void nxp_imx8mq_evk_sram_setup(void)
> * 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
> + * 2. DDR is initialized and the TF-A trampoline is installed in the
> + * DRAM.
> *
> - * 4. BL31 blob is uploaded to OCRAM and the control is transfer to it
> + * 3. TF-A is executed and exits into the trampoline in RAM, which enters the
> + * PBL for the second time. DRAM setup done is indicated by a one in register
> + * x0 by the trampoline
Why change this and add additional register state here? Checking for
EL2 should work fine for this.
Regards,
Lucas
> *
> - * 5. BL31 exits EL3 into EL2 at address MX8MQ_ATF_BL33_BASE_ADDR,
> - * executing start_nxp_imx8mq_evk() the third time
> + * 4. The piggydata is loaded from the SD card and copied to the expected
> + * location in the DRAM.
> *
> - * 6. Standard barebox boot flow continues
> + * 5. Standard barebox boot flow continues
> */
> ENTRY_FUNCTION(start_nxp_imx8mq_evk, r0, r1, r2)
> {
> > + enum bootsource src = BOOTSOURCE_UNKNOWN;
> > + int instance = BOOTSOURCE_INSTANCE_UNKNOWN;
> > + int ret = -ENOTSUPP;
> > + const u8 *bl31;
> > + size_t bl31_size;
> +
> > imx8mq_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 register r0 does not contain 1, we are running for the first time
> > + * and need to initialize the DRAM, install the trampoline and run TF-A
> > + * (BL31).
> > + * Otherwise the 1 indicates that the DRAM setup and trampoline are
> > + * already installed and TF-A has been run. In this case we can skip
> > */
> > - if (current_el() == 3) {
> > - const u8 *bl31;
> > - size_t bl31_size;
> -
> > + if (r0 != 1) {
> > + nxp_imx8mq_evk_sram_setup();
> > + nxp_imx8mq_evk_install_tfa_trampoline();
> > get_builtin_firmware(imx8mq_bl31_bin, &bl31, &bl31_size);
> > imx8mq_atf_load_bl31(bl31, bl31_size);
> > }
>
> > + imx8_get_boot_source(&src, &instance);
> +
> > + if (src == BOOTSOURCE_MMC)
> > + ret = imx8_esdhc_load_piggy(instance);
> > + else
> > + BUG_ON(ret);
> > /*
> > * Standard entry we hit once we initialized both DDR and ATF
> > */
> > imx8mq_barebox_entry(__dtb_imx8mq_evk_start);
> }
> -
> diff --git a/arch/arm/boards/nxp-imx8mq-evk/trampoline.S b/arch/arm/boards/nxp-imx8mq-evk/trampoline.S
> new file mode 100644
> index 0000000..49bd750
> --- /dev/null
> +++ b/arch/arm/boards/nxp-imx8mq-evk/trampoline.S
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: (GPL-2.0) */
> +#include <linux/linkage.h>
> +#include <asm/sections.h>
> > + .section .trampoline,"a"
> > + .globl trampoline_start
> +trampoline_start:
> > > + ldr w19, trampoline_end
> > + mov x0, #0x1
> > + br x19
> > + .globl trampoline_end
> +trampoline_end:
> diff --git a/images/Makefile.imx b/images/Makefile.imx
> index 76beccb..0fd1fe1 100644
> --- a/images/Makefile.imx
> +++ b/images/Makefile.imx
> @@ -582,8 +582,7 @@ image-$(CONFIG_MACH_ZII_IMX7D_DEV) += barebox-zii-imx7d-dev.img
> # ----------------------- i.MX8mq based boards --------------------------
> pblb-$(CONFIG_MACH_NXP_IMX8MQ_EVK) += start_nxp_imx8mq_evk
> CFG_start_nxp_imx8mq_evk.pblb.imximg = $(board)/nxp-imx8mq-evk/flash-header-imx8mq-evk.imxcfg
> -MAX_PBL_MEMORY_SIZE_start_nxp_imx8mq_evk = 0x3f000
> -FILE_barebox-nxp-imx8mq-evk.img = start_nxp_imx8mq_evk.pblb.imximg
> +FILE_barebox-nxp-imx8mq-evk.img = start_nxp_imx8mq_evk.pblb.pimximg
> image-$(CONFIG_MACH_NXP_IMX8MQ_EVK) += barebox-nxp-imx8mq-evk.img
>
> pblb-$(CONFIG_MACH_ZII_IMX8MQ_DEV) += start_zii_imx8mq_dev
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