bl2-el3: Add BL2_EL3 image
This patch enables BL2 to execute at the highest exception level
without any dependancy on TF BL1. This enables platforms which already
have a non-TF Boot ROM to directly load and execute BL2 and subsequent BL
stages without need for BL1. This is not currently possible because
BL2 executes at S-EL1 and cannot jump straight to EL3.
Change-Id: Ief1efca4598560b1b8c8e61fbe26d1f44e929d69
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
diff --git a/bl2/aarch32/bl2_el3_entrypoint.S b/bl2/aarch32/bl2_el3_entrypoint.S
new file mode 100644
index 0000000..997b069
--- /dev/null
+++ b/bl2/aarch32/bl2_el3_entrypoint.S
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <bl_common.h>
+#include <el3_common_macros.S>
+
+
+ .globl bl2_entrypoint
+ .globl bl2_run_next_image
+
+
+func bl2_entrypoint
+ /* Save arguments x0-x3 from previous Boot loader */
+ mov r9, r0
+ mov r10, r1
+ mov r11, r2
+ mov r12, r3
+
+ el3_entrypoint_common \
+ _init_sctlr=1 \
+ _warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS \
+ _secondary_cold_boot=!COLD_BOOT_SINGLE_CPU \
+ _init_memory=1 \
+ _init_c_runtime=1 \
+ _exception_vectors=bl2_vector_table
+
+ /*
+ * Restore parameters of boot rom
+ */
+ mov r0, r9
+ mov r1, r10
+ mov r2, r11
+ mov r3, r12
+
+ bl bl2_el3_early_platform_setup
+ bl bl2_el3_plat_arch_setup
+
+ /* ---------------------------------------------
+ * Jump to main function.
+ * ---------------------------------------------
+ */
+ bl bl2_main
+
+ /* ---------------------------------------------
+ * Should never reach this point.
+ * ---------------------------------------------
+ */
+ no_ret plat_panic_handler
+
+endfunc bl2_entrypoint
+
+func bl2_run_next_image
+ mov r8,r0
+
+ /*
+ * MMU needs to be disabled because both BL2 and BL32 execute
+ * in PL1, and therefore share the same address space.
+ * BL32 will initialize the address space according to its
+ * own requirement.
+ */
+ bl disable_mmu_icache_secure
+ stcopr r0, TLBIALL
+ dsb sy
+ isb
+ mov r0, r8
+ bl bl2_el3_plat_prepare_exit
+
+ /*
+ * Extract PC and SPSR based on struct `entry_point_info_t`
+ * and load it in LR and SPSR registers respectively.
+ */
+ ldr lr, [r8, #ENTRY_POINT_INFO_PC_OFFSET]
+ ldr r1, [r8, #(ENTRY_POINT_INFO_PC_OFFSET + 4)]
+ msr spsr, r1
+
+ add r8, r8, #ENTRY_POINT_INFO_ARGS_OFFSET
+ ldm r8, {r0, r1, r2, r3}
+ eret
+endfunc bl2_run_next_image