Merge pull request #1000 from dp-arm/dp/aarch32-boot

juno/aarch32: Fix boot on Cortex A57 and A72

plat/arm/board/juno/aarch64/juno_helpers.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -266,6 +266,16 @@ endfunc plat_get_my_entrypoint
  * to AArch32 mode is then requested by writing into RMR_EL3.
  */
 func juno_reset_to_aarch32_state
+	/*
+	 * Invalidate all caches before the warm reset to AArch32 state.
+	 * This is required on the Juno AArch32 boot flow because the L2
+	 * unified cache may contain code and data from when the processor
+	 * was still executing in AArch64 state.  This code only runs on
+	 * the primary core, all other cores are powered down.
+	 */
+	mov	x0, #DCISW
+	bl	dcsw_op_all
+
 	emit_movw	w0, BL32_BASE
 	emit_movt	w1, BL32_BASE
 	/* opcode "bx r0" to branch using r0 in AArch32 mode */

plat/arm/board/juno/juno_bl2_setup.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -29,4 +29,28 @@ int bl2_plat_handle_post_image_load(unsigned int image_id)
 
 	return err;
 }
+
+/*
+ * We need to override some of the platform functions when booting SP_MIN
+ * on Juno AArch32.
+ */
+
+static unsigned int scp_boot_config;
+
+void bl2_early_platform_setup(meminfo_t *mem_layout)
+{
+	arm_bl2_early_platform_setup(mem_layout);
+
+	/* Save SCP Boot config before it gets overwritten by SCP_BL2 loading */
+	VERBOSE("BL2: Saving SCP Boot config = 0x%x\n", scp_boot_config);
+	scp_boot_config = mmio_read_32(SCP_BOOT_CFG_ADDR);
+}
+
+void bl2_platform_setup(void)
+{
+	arm_bl2_platform_setup();
+
+	mmio_write_32(SCP_BOOT_CFG_ADDR, scp_boot_config);
+	VERBOSE("BL2: Restored SCP Boot config = 0x%x\n", scp_boot_config);
+}
 #endif /* JUNO_AARCH32_EL3_RUNTIME */