From 944c7a317675d8dbf082a2f144fec1139a5cb811 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Tue, 25 Aug 2015 13:49:41 +0200 Subject: [PATCH] arm: mvebu: Add option to use UART xmodem protocol via kwboot This patch enables the use of the kwboot tool, to boot mainline U-Boot on the Marvell Armada XP/38x SoC's. This is done by returning to the SoC's BootROM after SPL has initialized the SDRAM. We need to make sure to not reconfigure the internal register space and MBARs. Otherwise the BootROM will not be able to continue after SPL jumps back to it. To use this feature, please don't forget to change the BOOT_FROM line in your board specfic kwbimage.cfg file this way: BOOT_FROM uart Tested on these Marvell eval boards: DB-MV784MP-GP - Armada XP DB-88F6820-GP - Armada 38x Signed-off-by: Stefan Roese Cc: Dirk Eibach Cc: Kevin Smith Cc: Luka Perkov --- Makefile | 12 +++++++++++- arch/arm/mach-mvebu/Kconfig | 10 ++++++++++ arch/arm/mach-mvebu/include/mach/cpu.h | 2 ++ arch/arm/mach-mvebu/include/mach/soc.h | 2 +- arch/arm/mach-mvebu/lowlevel_spl.S | 16 ++++++++++++++++ arch/arm/mach-mvebu/spl.c | 25 +++++++++++++++++++++++++ 6 files changed, 65 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index fd06024104..3b2eebf4b7 100644 --- a/Makefile +++ b/Makefile @@ -901,7 +901,7 @@ MKIMAGEFLAGS_u-boot.kwb = -n $(srctree)/$(CONFIG_SYS_KWD_CONFIG:"%"=%) \ -T kwbimage -a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_TEXT_BASE) MKIMAGEFLAGS_u-boot-spl.kwb = -n $(srctree)/$(CONFIG_SYS_KWD_CONFIG:"%"=%) \ - -T kwbimage -a $(CONFIG_SPL_TEXT_BASE) -e $(CONFIG_SPL_TEXT_BASE) + -T kwbimage -a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_TEXT_BASE) MKIMAGEFLAGS_u-boot.pbl = -n $(srctree)/$(CONFIG_SYS_FSL_PBL_RCW:"%"=%) \ -R $(srctree)/$(CONFIG_SYS_FSL_PBL_PBI:"%"=%) -T pblimage @@ -909,8 +909,18 @@ MKIMAGEFLAGS_u-boot.pbl = -n $(srctree)/$(CONFIG_SYS_FSL_PBL_RCW:"%"=%) \ u-boot.img u-boot.kwb u-boot.pbl: u-boot.bin FORCE $(call if_changed,mkimage) +# If the kwboot xmodem protocol is used, to boot U-Boot on the MVEBU +# SoC's, the SPL U-Boot returns to the BootROM after it completes +# the SDRAM setup. The BootROM expects no U-Boot header in the main +# U-Boot image. So we need to combine SPL and u-boot.bin instead of +# u-boot.img in this case. +ifdef CONFIG_MVEBU_BOOTROM_UARTBOOT +u-boot-spl.kwb: u-boot.bin spl/u-boot-spl.bin FORCE + $(call if_changed,mkimage) +else u-boot-spl.kwb: u-boot.img spl/u-boot-spl.bin FORCE $(call if_changed,mkimage) +endif MKIMAGEFLAGS_u-boot-dtb.img = $(MKIMAGEFLAGS_u-boot.img) diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig index 1aa964091a..79ff0e8278 100644 --- a/arch/arm/mach-mvebu/Kconfig +++ b/arch/arm/mach-mvebu/Kconfig @@ -18,4 +18,14 @@ endchoice config SYS_SOC default "mvebu" +config MVEBU_BOOTROM_UARTBOOT + bool "Use kwboot to boot via BootROM xmodem protocol" + help + This option provides support for booting via the Marvell + xmodem protocol, used by the kwboot tool. + + Please don't forget to configure the boot device in + the board specific kwbimage.cfg file this way: + BOOT_FROM uart + endif diff --git a/arch/arm/mach-mvebu/include/mach/cpu.h b/arch/arm/mach-mvebu/include/mach/cpu.h index 6fa41736e2..5e8bf0c4ce 100644 --- a/arch/arm/mach-mvebu/include/mach/cpu.h +++ b/arch/arm/mach-mvebu/include/mach/cpu.h @@ -119,6 +119,8 @@ int mvebu_mbus_probe(struct mbus_win windows[], int count); int mvebu_soc_family(void); u32 mvebu_get_nand_clock(void); +void return_to_bootrom(void); + int mv_sdh_init(unsigned long regbase, u32 max_clk, u32 min_clk, u32 quirks); /* diff --git a/arch/arm/mach-mvebu/include/mach/soc.h b/arch/arm/mach-mvebu/include/mach/soc.h index 02c21bcded..22abde080e 100644 --- a/arch/arm/mach-mvebu/include/mach/soc.h +++ b/arch/arm/mach-mvebu/include/mach/soc.h @@ -31,7 +31,7 @@ /* SOC specific definations */ #define INTREG_BASE 0xd0000000 #define INTREG_BASE_ADDR_REG (INTREG_BASE + 0x20080) -#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SYS_MVEBU_DDR_A38X) +#if defined(CONFIG_SPL_BUILD) /* * On A38x switching the regs base address without running from * SDRAM doesn't seem to work. So let the SPL still use the diff --git a/arch/arm/mach-mvebu/lowlevel_spl.S b/arch/arm/mach-mvebu/lowlevel_spl.S index 69da7fe7af..2e2181ecea 100644 --- a/arch/arm/mach-mvebu/lowlevel_spl.S +++ b/arch/arm/mach-mvebu/lowlevel_spl.S @@ -5,10 +5,26 @@ #include #include +#ifdef CONFIG_MVEBU_BOOTROM_UARTBOOT ENTRY(save_boot_params) + stmfd sp!, {r0 - r12, lr} /* @ save registers on stack */ + ldr r12, =CONFIG_SPL_BOOTROM_SAVE + str sp, [r12] b save_boot_params_ret ENDPROC(save_boot_params) +ENTRY(return_to_bootrom) + ldr r12, =CONFIG_SPL_BOOTROM_SAVE + ldr sp, [r12] + mov r0, #0x0 /* @ return value: 0x0 NO_ERR */ + ldmfd sp!, {r0 - r12, pc} /* @ restore regs and return */ +ENDPROC(return_to_bootrom) +#else +ENTRY(save_boot_params) + b save_boot_params_ret +ENDPROC(save_boot_params) +#endif + /* * cache_inv - invalidate Cache line * r0 - dest diff --git a/arch/arm/mach-mvebu/spl.c b/arch/arm/mach-mvebu/spl.c index af61ded42e..26ff1a24ac 100644 --- a/arch/arm/mach-mvebu/spl.c +++ b/arch/arm/mach-mvebu/spl.c @@ -34,8 +34,18 @@ void board_init_f(ulong dummy) /* Set global data pointer */ gd = &gdata; +#ifndef CONFIG_MVEBU_BOOTROM_UARTBOOT + /* + * Only call arch_cpu_init() when not returning to the + * Marvell BootROM, which is done when booting via + * the xmodem protocol (kwboot tool). Otherwise the + * internal register will get remapped and the BootROM + * can't continue to run correctly. + */ + /* Linux expects the internal registers to be at 0xf1000000 */ arch_cpu_init(); +#endif /* * Pin muxing needs to be done before UART output, since @@ -54,5 +64,20 @@ void board_init_f(ulong dummy) /* Setup DDR */ ddr3_init(); +#ifdef CONFIG_MVEBU_BOOTROM_UARTBOOT + /* + * Return to the BootROM to continue the Marvell xmodem + * UART boot protocol. As initiated by the kwboot tool. + * + * This can only be done by the BootROM and not by the + * U-Boot SPL infrastructure, since the beginning of the + * image is already read and interpreted by the BootROM. + * SPL has no chance to receive this information. So we + * need to return to the BootROM to enable this xmodem + * UART download. + */ + return_to_bootrom(); +#endif + board_init_r(NULL, 0); } -- 2.25.1