FWU: Add Generic BL2U FWU image support in BL2

The Firmware Update (FWU) feature needs support for an optional
secure world image, BL2U, to allow additional secure world
initialization required by FWU, for example DDR initialization.

This patch adds generic framework support to create BL2U.

NOTE: A platform makefile must supply additional `BL2U_SOURCES`
      to build the bl2u target. A subsequent patch adds bl2u
      support for ARM platforms.

Change-Id: If2ce036199bb40b39b7f91a9332106bcd4e25413

1 files changed, 127 insertions, 0 deletions

diff --git a/bl2u/aarch64/bl2u_entrypoint.S b/bl2u/aarch64/bl2u_entrypoint.S
new file mode 100644
index 00000000..c9aad81f
--- /dev/null
+++ b/bl2u/aarch64/bl2u_entrypoint.S
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <bl_common.h>
+
+
+	.globl	bl2u_entrypoint
+
+
+func bl2u_entrypoint
+	/*---------------------------------------------
+	 * Store the extents of the tzram available to
+	 * BL2U and other platform specific information
+	 * for future use. x0 is currently not used.
+	 * ---------------------------------------------
+	 */
+	mov	x20, x1
+	mov	x21, x2
+
+	/* ---------------------------------------------
+	 * Set the exception vector to something sane.
+	 * ---------------------------------------------
+	 */
+	adr	x0, early_exceptions
+	msr	vbar_el1, x0
+	isb
+
+	/* ---------------------------------------------
+	 * Enable the SError interrupt now that the
+	 * exception vectors have been setup.
+	 * ---------------------------------------------
+	 */
+	msr	daifclr, #DAIF_ABT_BIT
+
+	/* ---------------------------------------------
+	 * Enable the instruction cache, stack pointer
+	 * and data access alignment checks
+	 * ---------------------------------------------
+	 */
+	mov	x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
+	mrs	x0, sctlr_el1
+	orr	x0, x0, x1
+	msr	sctlr_el1, x0
+	isb
+
+	/* ---------------------------------------------
+	 * Invalidate the RW memory used by the BL2U
+	 * image. This includes the data and NOBITS
+	 * sections. This is done to safeguard against
+	 * possible corruption of this memory by dirty
+	 * cache lines in a system cache as a result of
+	 * use by an earlier boot loader stage.
+	 * ---------------------------------------------
+	 */
+	adr	x0, __RW_START__
+	adr	x1, __RW_END__
+	sub	x1, x1, x0
+	bl	inv_dcache_range
+
+	/* ---------------------------------------------
+	 * Zero out NOBITS sections. There are 2 of them:
+	 *   - the .bss section;
+	 *   - the coherent memory section.
+	 * ---------------------------------------------
+	 */
+	ldr	x0, =__BSS_START__
+	ldr	x1, =__BSS_SIZE__
+	bl	zeromem16
+
+	/* --------------------------------------------
+	 * Allocate a stack whose memory will be marked
+	 * as Normal-IS-WBWA when the MMU is enabled.
+	 * There is no risk of reading stale stack
+	 * memory after enabling the MMU as only the
+	 * primary cpu is running at the moment.
+	 * --------------------------------------------
+	 */
+	bl	plat_set_my_stack
+
+	/* ---------------------------------------------
+	 * Perform early platform setup & platform
+	 * specific early arch. setup e.g. mmu setup
+	 * ---------------------------------------------
+	 */
+	mov	x0, x20
+	mov	x1, x21
+	bl	bl2u_early_platform_setup
+	bl	bl2u_plat_arch_setup
+
+	/* ---------------------------------------------
+	 * Jump to bl2u_main function.
+	 * ---------------------------------------------
+	 */
+	bl	bl2u_main
+
+_panic:
+	b	_panic
+endfunc bl2u_entrypoint