arm: mvebu: Add runtime detection of UART (xmodem) boot-mode

This patch adds runtime detection of the Marvell UART boot-mode (xmodem
protocol). If this boot-mode is detected, SPL will return to the
BootROM to continue the UART booting.

With this patch its now possible, to generate a U-Boot image that
can be booted either from the strapped boot-device (e.g. SPI NOR, MMC,
etc) or via the xmodem protocol from the UART. In the UART case,
the kwboot tool will dynamically insert the UART boot-device type
into the image. And also patch the load address in the header, so
that the mkimage header will be skipped (as its not expected by the
Marvell BootROM).

This simplifies the development for Armada XP / 38x based boards.
As no special images need to be generated by selecting the
MVEBU_BOOTROM_UARTBOOT Kconfig option.

Since the Kconfig option MVEBU_BOOTROM_UARTBOOT is not needed any
more, its now completely removed.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Cc: Dirk Eibach <dirk.eibach@gdsys.cc>
Cc: Phil Sutter <phil@nwl.cc>
Cc: Kevin Smith <kevin.smith@elecsyscorp.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/arch/arm/mach-mvebu/spl.c b/arch/arm/mach-mvebu/spl.c
index 778996eff5..0879873b97 100644
--- a/arch/arm/mach-mvebu/spl.c
+++ b/arch/arm/mach-mvebu/spl.c
@@ -20,8 +20,23 @@ static u32 get_boot_device(void)
 	u32 val;
 	u32 boot_device;
 
+	/*
+	 * First check, if UART boot-mode is active. This can only
+	 * be done, via the bootrom error register. Here the
+	 * MSB marks if the UART mode is active.
+	 */
+	val = readl(CONFIG_BOOTROM_ERR_REG);
+	boot_device = (val & BOOTROM_ERR_MODE_MASK) >> BOOTROM_ERR_MODE_OFFS;
+	debug("BOOTROM_REG=0x%08x boot_device=0x%x\n", val, boot_device);
+	if (boot_device == BOOTROM_ERR_MODE_UART)
+		return BOOT_DEVICE_UART;
+
+	/*
+	 * Now check the SAR register for the strapped boot-device
+	 */
 	val = readl(CONFIG_SAR_REG);	/* SAR - Sample At Reset */
 	boot_device = (val & BOOT_DEV_SEL_MASK) >> BOOT_DEV_SEL_OFFS;
+	debug("SAR_REG=0x%08x boot_device=0x%x\n", val, boot_device);
 	switch (boot_device) {
 #ifdef CONFIG_SPL_MMC_SUPPORT
 	case BOOT_FROM_MMC:
@@ -90,7 +105,6 @@ 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.
@@ -102,6 +116,6 @@ void board_init_f(ulong dummy)
 	 * need to return to the BootROM to enable this xmodem
 	 * UART download.
 	 */
-	return_to_bootrom();
-#endif
+	if (get_boot_device() == BOOT_DEVICE_UART)
+		return_to_bootrom();
 }