5 files changed, 54 insertions, 1 deletions
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 <config.h>
 #include <linux/linkage.h>
 
+#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);
 }