armv7R: K3: j721e: Store boot index from ROM

Obtain the boot index as left behind by the device boot ROM and store
it in scratch pad SRAM for later use before it may get overwritten.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>

diff --git a/arch/arm/mach-k3/j721e_init.c b/arch/arm/mach-k3/j721e_init.c
index ba6a1cf..b7f0546 100644 (file)
--- a/arch/arm/mach-k3/j721e_init.c
+++ b/arch/arm/mach-k3/j721e_init.c
@@ -53,12 +53,25 @@ static void ctrl_mmr_unlock(void)
        mmr_unlock(CTRL_MMR0_BASE, 7);
 }
 
+/*
+ * This uninitialized global variable would normal end up in the .bss section,
+ * but the .bss is cleared between writing and reading this variable, so move
+ * it to the .data section.
+ */
+u32 bootindex __attribute__((section(".data")));
+
+static void store_boot_index_from_rom(void)
+{
+       bootindex = *(u32 *)(CONFIG_SYS_K3_BOOT_PARAM_TABLE_INDEX);
+}
+
 void board_init_f(ulong dummy)
 {
        /*
-        * ToDo:
-        * - Store boot rom index.
+        * Cannot delay this further as there is a chance that
+        * K3_BOOT_PARAM_TABLE_INDEX can be over written by SPL MALLOC section.
         */
+       store_boot_index_from_rom();
 
        /* Make all control module registers accessible */
        ctrl_mmr_unlock();