Hello, I am writing this from a standalone Sapphire board [1], that is, without the Excavator base board. The CPU is the Rockchip RK3399, which implements ARMv8.0-A.
Currently the boot process is: 1.- Boot ROM 2.- SPL, provided as closed source binary blob [2] 3.- ATF, closed source binary blob [3] (not using the one from [2] because of stability issues) 4.- Mainline u-boot, master branch 5.- Mainline linux, master branch
I would like to use an opensource boot process. As a first approach I try to completely remove the ATF and replace the SPL with the one from u-boot. The modified boot process looks like: 1.- Boot ROM 2.- SPL, from mainline u-boot, master branch 3.- Mainline u-boot, master branch 4.- Mainline linux, master branch But it is not working.
The replaced SPL works fine and loads u-boot. U-boot also works fine, loads linux and jumps into it. But then, linux never gets executed.
I have traced the issue to: arch/arm/include/asm/macro.h 202: msr spsr_el3, \tmp 203: msr elr_el3, \ep 204: eret // This is the last instruction executed
For testing, I have also set CONFIG_ARMV8_SWITCH_TO_EL1 and checked that switch_to_el1 from arch/arm/lib/bootm.c is not reached.
At this point I have a few questions: 1.- Is my first approach feasible? That is, is it possible to boot this CPU without ATF? 2.- If so, what should I do to make it work? Probably it is just a configuration issue, but I do not know what to check. [4] 3.- Else, why do I need ATF?
Regards, Vicenç.
[1] http://opensource.rock-chips.com/wiki_Excavator_sapphire_board [2] https://github.com/rockchip-linux/rkbin/tree/29mirror [3] https://raw.githubusercontent.com/nightseas/armbian-build/master/packages/bl... [4] CONFIG_ARM=y CONFIG_ARCH_ROCKCHIP=y CONFIG_SYS_TEXT_BASE=0x00200000 CONFIG_SPL_LIBCOMMON_SUPPORT=y CONFIG_SPL_LIBGENERIC_SUPPORT=y CONFIG_SYS_MALLOC_F_LEN=0x4000 CONFIG_ROCKCHIP_RK3399=y CONFIG_ROCKCHIP_SPL_RESERVE_IRAM=0x4000 CONFIG_SPL_STACK_R_ADDR=0x80000 # CONFIG_PSCI_RESET is not set CONFIG_CMD_HDMIDETECT=y CONFIG_DEFAULT_DEVICE_TREE="rk3399-evb" CONFIG_DEBUG_UART=y CONFIG_BOOTDELAY=1 # CONFIG_DISPLAY_CPUINFO is not set # CONFIG_DISPLAY_BOARDINFO is not set CONFIG_SPL_STACK_R=y CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x4000 # CONFIG_CMD_IMI is not set # CONFIG_CMD_XIMG is not set # CONFIG_CMD_SAVEENV is not set # CONFIG_CMD_FLASH is not set # CONFIG_CMD_LOADB is not set # CONFIG_CMD_LOADS is not set CONFIG_CMD_MMC=y CONFIG_CMD_USB=y # CONFIG_CMD_SETEXPR is not set # CONFIG_CMD_NET is not set # CONFIG_DOS_PARTITION is not set # CONFIG_ISO_PARTITION is not set CONFIG_SPL_OF_CONTROL=y CONFIG_REGMAP=y CONFIG_SPL_REGMAP=y CONFIG_SYSCON=y CONFIG_SPL_SYSCON=y CONFIG_CLK=y CONFIG_SPL_CLK=y CONFIG_ROCKCHIP_GPIO=y CONFIG_SYS_I2C_ROCKCHIP=y # CONFIG_MMC_WRITE is not set # CONFIG_MMC_HW_PARTITIONING is not set CONFIG_MMC_DW=y CONFIG_MMC_SDHCI=y CONFIG_MMC_SDHCI_ROCKCHIP=y CONFIG_DM_ETH=y # CONFIG_NETDEVICES is not set CONFIG_PINCTRL=y CONFIG_SPL_PINCTRL=y CONFIG_PINCTRL_ROCKCHIP_RK3399=y CONFIG_DM_PMIC=y CONFIG_PMIC_RK8XX=y CONFIG_REGULATOR_PWM=y CONFIG_DM_REGULATOR_FIXED=y CONFIG_REGULATOR_RK8XX=y CONFIG_PWM_ROCKCHIP=y CONFIG_RAM=y CONFIG_SPL_RAM=y CONFIG_BAUDRATE=1500000 CONFIG_DEBUG_UART_BASE=0xFF1A0000 CONFIG_DEBUG_UART_CLOCK=24000000 CONFIG_DEBUG_UART_SHIFT=2 CONFIG_SYSRESET=y CONFIG_USB=y CONFIG_USB_XHCI_HCD=y CONFIG_USB_XHCI_DWC3=y CONFIG_USB_EHCI_HCD=y CONFIG_USB_EHCI_GENERIC=y CONFIG_USB_STORAGE=y CONFIG_USB_KEYBOARD=y CONFIG_USB_HOST_ETHER=y CONFIG_USB_ETHER_ASIX=y CONFIG_USB_ETHER_ASIX88179=y CONFIG_USB_ETHER_MCS7830=y CONFIG_USB_ETHER_RTL8152=y CONFIG_USB_ETHER_SMSC95XX=y CONFIG_DM_VIDEO=y # CONFIG_BACKLIGHT_PWM is not set # CONFIG_VIDEO_BPP8 is not set # CONFIG_VIDEO_BPP16 is not set # CONFIG_VIDEO_BPP32 is not set # CONFIG_VIDEO_ANSI is not set # CONFIG_SYS_WHITE_ON_BLACK is not set CONFIG_DISPLAY=y CONFIG_VIDEO_ROCKCHIP=y CONFIG_DISPLAY_ROCKCHIP_HDMI=y # CONFIG_FAT_WRITE is not set CONFIG_USE_TINY_PRINTF=y CONFIG_ERRNO_STR=y # CONFIG_EFI_LOADER is not set