stm32mp1: select boot device and partition

Bootrom loads SPL from SDCARD or eMMC
according BootPin selection.

Then SPL loads U-Boot on the same mmc device
with the following predefined GPT partitioning:

on SDCARD: gpt partitioning
  1: SPL
  2: SPL#2
  3: U-Boot
  4: bootable partition

on eMMC:
  The 2 boot partitions are used for SPL (2 copy)
    boot1: SPL
    boot2: SPL#2
  The user partition use gpt partitioning
    1: U-Boot
    2: bootable partition

This patch select the correct SPL partition
(3 for SDCARD on mmc0 and 1 for eMMC on mmc1)
according the BootRom information saved in TAMP register
and based on configuration flasg:
- CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
  => for BOOT_DEVICE_MMC1 or mmc 0 in U-Boot
- CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_MMC2 (new)
  => for BOOT_DEVICE_MMC2 or mmc 1 in U-Boot

And the correct boot_targets is selected according the environment
variables boot_device and boot_instance, with preboot command,
to search the bootable partition with kernel on this device
(generic distro support).

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

arch/arm/mach-stm32mp/Kconfig

@@ -38,6 +38,14 @@ config SYS_TEXT_BASE
 		when DDR driver is used:
 		  DDR + 1MB (0xC0100000)
 
+config SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_MMC2
+	hex "Partition on MMC2 to use to load U-Boot from"
+	depends on SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
+	default 1
+	help
+	  Partition on the second MMC to load U-Boot from when the MMC is being
+	  used in raw mode
+
 source "board/st/stm32mp1/Kconfig"
 
 endif

arch/arm/mach-stm32mp/spl.c

@@ -7,9 +7,27 @@
 #include <common.h>
 #include <dm.h>
 #include <spl.h>
+#include <asm/io.h>
 
 u32 spl_boot_device(void)
 {
+	u32 boot_mode;
+
+	boot_mode = (readl(TAMP_BOOT_CONTEXT) & TAMP_BOOT_MODE_MASK) >>
+		    TAMP_BOOT_MODE_SHIFT;
+	clrsetbits_le32(TAMP_BOOT_CONTEXT,
+			TAMP_BOOT_MODE_MASK,
+			boot_mode << TAMP_BOOT_MODE_SHIFT);
+
+	switch (boot_mode) {
+	case BOOT_FLASH_SD_1:
+	case BOOT_FLASH_EMMC_1:
+		return BOOT_DEVICE_MMC1;
+	case BOOT_FLASH_SD_2:
+	case BOOT_FLASH_EMMC_2:
+		return BOOT_DEVICE_MMC2;
+	}
+
 	return BOOT_DEVICE_MMC1;
 }
 
@@ -18,6 +36,18 @@ u32 spl_boot_mode(const u32 boot_device)
 	return MMCSD_MODE_RAW;
 }
 
+int spl_boot_partition(const u32 boot_device)
+{
+	switch (boot_device) {
+	case BOOT_DEVICE_MMC1:
+		return CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION;
+	case BOOT_DEVICE_MMC2:
+		return CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_MMC2;
+	default:
+		return -EINVAL;
+	}
+}
+
 void board_init_f(ulong dummy)
 {
 	struct udevice *dev;

include/configs/stm32mp1.h

@@ -82,6 +82,12 @@
 
 #include <config_distro_bootcmd.h>
 
+#define STM32MP_PREBOOT	\
+	"echo \"Boot over ${boot_device}${boot_instance}!\"; " \
+	"if test \"${boot_device}\" = \"mmc\"; then " \
+		"env set boot_targets \"mmc${boot_instance}\"; "\
+	"fi;"
+
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	"scriptaddr=0xC0000000\0" \
 	"pxefile_addr_r=0xC0000000\0" \
@@ -90,6 +96,7 @@
 	"ramdisk_addr_r=0xC4100000\0" \
 	"fdt_high=0xffffffff\0" \
 	"initrd_high=0xffffffff\0" \
+	"preboot=" STM32MP_PREBOOT "\0" \
 	BOOTENV
 
 #endif /* ifndef CONFIG_SPL_BUILD */