Merge pull request #310 from sandrine-bailleux/sb/tf-issue-304-phase1

Enhance BL3-1 entrypoint handling to support non-TF boot firmware - Phase 1

Makefile

@@ -76,6 +76,9 @@ CREATE_KEYS		:= 1
 # Flags to build TF with Trusted Boot support
 TRUSTED_BOARD_BOOT	:= 0
 AUTH_MOD		:= none
+# By default, consider that the platform's reset address is not programmable.
+# The platform Makefile is free to override this value.
+PROGRAMMABLE_RESET_ADDRESS	:= 0
 
 # Checkpatch ignores
 CHECK_IGNORE		=	--ignore COMPLEX_MACRO \
@@ -272,6 +275,10 @@ $(eval $(call assert_boolean,CREATE_KEYS))
 $(eval $(call assert_boolean,TRUSTED_BOARD_BOOT))
 $(eval $(call add_define,TRUSTED_BOARD_BOOT))
 
+# Process PROGRAMMABLE_RESET_ADDRESS flag
+$(eval $(call assert_boolean,PROGRAMMABLE_RESET_ADDRESS))
+$(eval $(call add_define,PROGRAMMABLE_RESET_ADDRESS))
+
 ASFLAGS			+= 	-nostdinc -ffreestanding -Wa,--fatal-warnings	\
 				-Werror -Wmissing-include-dirs			\
 				-mgeneral-regs-only -D__ASSEMBLY__		\

bl1/aarch64/bl1_entrypoint.S

 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2015, 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:
@@ -29,7 +29,7 @@
  */
 
 #include <arch.h>
-#include <asm_macros.S>
+#include <el3_common_macros.S>
 
 	.globl	bl1_entrypoint
 
@@ -42,116 +42,19 @@
 	 */
 
 func bl1_entrypoint
-	/* ---------------------------------------------
-	 * Set the CPU endianness before doing anything
-	 * that might involve memory reads or writes.
-	 * ---------------------------------------------
-	 */
-	mrs	x0, sctlr_el3
-	bic	x0, x0, #SCTLR_EE_BIT
-	msr	sctlr_el3, x0
-	isb
-
-	/* ---------------------------------------------
-	 * Perform any processor specific actions upon
-	 * reset e.g. cache, tlb invalidations etc.
-	 * ---------------------------------------------
-	 */
-	bl	reset_handler
-
-	/* ---------------------------------------------
-	 * 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_el3
-	orr	x0, x0, x1
-	msr	sctlr_el3, x0
-	isb
-
-	/* ---------------------------------------------
-	 * Set the exception vector to something sane.
-	 * ---------------------------------------------
-	 */
-	adr	x0, bl1_exceptions
-	msr	vbar_el3, x0
-	isb
-
-	/* ---------------------------------------------
-	 * Enable the SError interrupt now that the
-	 * exception vectors have been setup.
-	 * ---------------------------------------------
-	 */
-	msr	daifclr, #DAIF_ABT_BIT
-
 	/* ---------------------------------------------------------------------
-	 * The initial state of the Architectural feature trap register
-	 * (CPTR_EL3) is unknown and it must be set to a known state. All
-	 * feature traps are disabled. Some bits in this register are marked as
-	 * Reserved and should not be modified.
-	 *
-	 * CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1
-	 *  or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2.
-	 * CPTR_EL3.TTA: This causes access to the Trace functionality to trap
-	 *  to EL3 when executed from EL0, EL1, EL2, or EL3. If system register
-	 *  access to trace functionality is not supported, this bit is RES0.
-	 * CPTR_EL3.TFP: This causes instructions that access the registers
-	 *  associated with Floating Point and Advanced SIMD execution to trap
-	 *  to EL3 when executed from any exception level, unless trapped to EL1
-	 *  or EL2.
+	 * If the reset address is programmable then bl1_entrypoint() is
+	 * executed only on the cold boot path. Therefore, we can skip the warm
+	 * boot mailbox mechanism.
 	 * ---------------------------------------------------------------------
 	 */
-	mrs	x0, cptr_el3
-	bic	w0, w0, #TCPAC_BIT
-	bic	w0, w0, #TTA_BIT
-	bic	w0, w0, #TFP_BIT
-	msr	cptr_el3, x0
-
-	/* -------------------------------------------------------
-	 * Will not return from this macro if it is a warm boot.
-	 * -------------------------------------------------------
-	 */
-	wait_for_entrypoint
-
-	bl	platform_mem_init
-
-	/* ---------------------------------------------
-	 * Init C runtime environment.
-	 *   - Zero-initialise the NOBITS sections.
-	 *     There are 2 of them:
-	 *       - the .bss section;
-	 *       - the coherent memory section.
-	 *   - Copy the data section from BL1 image
-	 *     (stored in ROM) to the correct location
-	 *     in RAM.
-	 * ---------------------------------------------
-	 */
-	ldr	x0, =__BSS_START__
-	ldr	x1, =__BSS_SIZE__
-	bl	zeromem16
-
-#if USE_COHERENT_MEM
-	ldr	x0, =__COHERENT_RAM_START__
-	ldr	x1, =__COHERENT_RAM_UNALIGNED_SIZE__
-	bl	zeromem16
-#endif
-
-	ldr	x0, =__DATA_RAM_START__
-	ldr	x1, =__DATA_ROM_START__
-	ldr	x2, =__DATA_SIZE__
-	bl	memcpy16
-
-	/* --------------------------------------------
-	 * 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.
-	 * --------------------------------------------
-	 */
-	mrs	x0, mpidr_el1
-	bl	platform_set_stack
+	el3_entrypoint_common					\
+		_set_endian=1					\
+		_warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS	\
+		_secondary_cold_boot=1				\
+		_init_memory=1					\
+		_init_c_runtime=1				\
+		_exception_vectors=bl1_exceptions
 
 	/* ---------------------------------------------
 	 * Architectural init. can be generic e.g.

bl31/aarch64/bl31_entrypoint.S

 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2015, 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:
@@ -29,8 +29,8 @@
  */
 
 #include <arch.h>
-#include <asm_macros.S>
 #include <bl_common.h>
+#include <el3_common_macros.S>
 
 	.globl	bl31_entrypoint
 
@@ -42,154 +42,68 @@
 	 */
 
 func bl31_entrypoint
+#if !RESET_TO_BL31
 	/* ---------------------------------------------------------------
 	 * Preceding bootloader has populated x0 with a pointer to a
 	 * 'bl31_params' structure & x1 with a pointer to platform
 	 * specific structure
 	 * ---------------------------------------------------------------
 	 */
-#if !RESET_TO_BL31
 	mov	x20, x0
 	mov	x21, x1
-#else
-	/* ---------------------------------------------
-	 * Set the CPU endianness before doing anything
-	 * that might involve memory reads or writes.
-	 * ---------------------------------------------
-	 */
-	mrs	x0, sctlr_el3
-	bic	x0, x0, #SCTLR_EE_BIT
-	msr	sctlr_el3, x0
-	isb
-#endif
-
-	/* ---------------------------------------------
-	 * When RESET_TO_BL31 is true, perform any
-	 * processor specific actions upon reset e.g.
-	 * cache, tlb invalidations, errata workarounds
-	 * etc.
-	 * When RESET_TO_BL31 is false, perform any
-	 * processor specific actions which undo or are
-	 * in addition to the actions performed by the
-	 * reset handler in the Boot ROM (BL1).
-	 * ---------------------------------------------
-	 */
-	bl	reset_handler
-
-	/* ---------------------------------------------
-	 * 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_el3
-	orr	x0, x0, x1
-	msr	sctlr_el3, x0
-	isb
-
-	/* ---------------------------------------------
-	 * Initialise cpu_data early to enable crash
-	 * reporting to have access to crash stack.
-	 * Since crash reporting depends on cpu_data to
-	 * report the unhandled exception, not
-	 * doing so can lead to recursive exceptions due
-	 * to a NULL TPIDR_EL3
-	 * ---------------------------------------------
-	 */
-	bl	init_cpu_data_ptr
-
-	/* ---------------------------------------------
-	 * Set the exception vector.
-	 * ---------------------------------------------
-	 */
-	adr	x1, runtime_exceptions
-	msr	vbar_el3, x1
-	isb
-
-	/* ---------------------------------------------
-	 * Enable the SError interrupt now that the
-	 * exception vectors have been setup.
-	 * ---------------------------------------------
-	 */
-	msr	daifclr, #DAIF_ABT_BIT
 
 	/* ---------------------------------------------------------------------
-	 * The initial state of the Architectural feature trap register
-	 * (CPTR_EL3) is unknown and it must be set to a known state. All
-	 * feature traps are disabled. Some bits in this register are marked as
-	 * Reserved and should not be modified.
+	 * For !RESET_TO_BL31 systems, only the primary CPU ever reaches
+	 * bl31_entrypoint() during the cold boot flow, so the cold/warm boot
+	 * and primary/secondary CPU logic should not be executed in this case.
 	 *
-	 * CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1
-	 *  or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2.
-	 * CPTR_EL3.TTA: This causes access to the Trace functionality to trap
-	 *  to EL3 when executed from EL0, EL1, EL2, or EL3. If system register
-	 *  access to trace functionality is not supported, this bit is RES0.
-	 * CPTR_EL3.TFP: This causes instructions that access the registers
-	 *  associated with Floating Point and Advanced SIMD execution to trap
-	 *  to EL3 when executed from any exception level, unless trapped to EL1
-	 *  or EL2.
+	 * Also, assume that the previous bootloader has already set up the CPU
+	 * endianness and has initialised the memory.
 	 * ---------------------------------------------------------------------
 	 */
-	mrs	x1, cptr_el3
-	bic	w1, w1, #TCPAC_BIT
-	bic	w1, w1, #TTA_BIT
-	bic	w1, w1, #TFP_BIT
-	msr	cptr_el3, x1
+	el3_entrypoint_common					\
+		_set_endian=0					\
+		_warm_boot_mailbox=0				\
+		_secondary_cold_boot=0				\
+		_init_memory=0					\
+		_init_c_runtime=1				\
+		_exception_vectors=runtime_exceptions
 
-#if RESET_TO_BL31
-	/* -------------------------------------------------------
-	 * Will not return from this macro if it is a warm boot.
-	 * -------------------------------------------------------
-	 */
-	wait_for_entrypoint
-	bl	platform_mem_init
-#endif
-
-	/* ---------------------------------------------
-	 * Zero out NOBITS sections. There are 2 of them:
-	 *   - the .bss section;
-	 *   - the coherent memory section.
-	 * ---------------------------------------------
+	/* ---------------------------------------------------------------------
+	 * Relay the previous bootloader's arguments to the platform layer
+	 * ---------------------------------------------------------------------
 	 */
-	ldr	x0, =__BSS_START__
-	ldr	x1, =__BSS_SIZE__
-	bl	zeromem16
-
-#if USE_COHERENT_MEM
-	ldr	x0, =__COHERENT_RAM_START__
-	ldr	x1, =__COHERENT_RAM_UNALIGNED_SIZE__
-	bl	zeromem16
-#endif
-
-	/* ---------------------------------------------
-	 * Use SP_EL0 for the C runtime stack.
-	 * ---------------------------------------------
+	mov	x0, x20
+	mov	x1, x21
+#else
+	/* ---------------------------------------------------------------------
+	 * For RESET_TO_BL31 systems which have a programmable reset address,
+	 * bl31_entrypoint() is executed only on the cold boot path so we can
+	 * skip the warm boot mailbox mechanism.
+	 * ---------------------------------------------------------------------
 	 */
-	msr	spsel, #0
+	el3_entrypoint_common					\
+		_set_endian=1					\
+		_warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS	\
+		_secondary_cold_boot=1				\
+		_init_memory=1					\
+		_init_c_runtime=1				\
+		_exception_vectors=runtime_exceptions
 
-	/* --------------------------------------------
-	 * 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.
-	 * --------------------------------------------
+	/* ---------------------------------------------------------------------
+	 * For RESET_TO_BL31 systems, BL3-1 is the first bootloader to run so
+	 * there's no argument to relay from a previous bootloader. Zero the
+	 * arguments passed to the platform layer to reflect that.
+	 * ---------------------------------------------------------------------
 	 */
-	mrs	x0, mpidr_el1
-	bl	platform_set_stack
+	mov	x0, 0
+	mov	x1, 0
+#endif /* RESET_TO_BL31 */
 
 	/* ---------------------------------------------
 	 * Perform platform specific early arch. setup
 	 * ---------------------------------------------
 	 */
-#if RESET_TO_BL31
-	mov	x0, 0
-	mov	x1, 0
-#else
-	mov	x0, x20
-	mov	x1, x21
-#endif
-
 	bl	bl31_early_platform_setup
 	bl	bl31_plat_arch_setup
 

docs/firmware-design.md

@@ -184,7 +184,7 @@ BL1 performs minimal architectural initialization as follows.
 
 #### Platform initialization
 
-BL1 enables issuing of snoop and DVM (Distributed Virtual Memory) requests from
+BL1 enables issuing of snoop and DVM (Distributed Virtual Memory) requests to
 the CCI slave interface corresponding to the cluster that includes the
 primary CPU. BL1 also initializes a UART (PL011 console), which enables access
 to the `printf` family of functions in BL1.
@@ -334,7 +334,9 @@ the clock frequency of the system counter, which is provided by the platform.
 BL3-1 performs detailed platform initialization, which enables normal world
 software to function correctly. It also retrieves entrypoint information for
 the BL3-3 image loaded by BL2 from the platform defined memory address populated
-by BL2. BL3-1 also initializes a UART (PL011 console), which enables
+by BL2. It enables issuing of snoop and DVM (Distributed Virtual Memory)
+requests to the CCI slave interface corresponding to the cluster that includes
+the primary CPU. BL3-1 also initializes a UART (PL011 console), which enables
 access to the `printf` family of functions in BL3-1.  It enables the system
 level implementation of the generic timer through the memory mapped interface.
 
@@ -412,8 +414,7 @@ updated to develop and exploit new functionality.
 
 #### Required CPU state when calling `bl31_entrypoint()` during cold boot
 
-This function must only be called by the primary CPU, if this is called by any
-other CPU the firmware will abort.
+This function must only be called by the primary CPU.
 
 On entry to this function the calling primary CPU must be executing in AArch64
 EL3, little-endian data access, and all interrupt sources masked:
@@ -543,11 +544,6 @@ implementation via a platform defined mechanism. On a cold boot, the platform
 must place any secondary CPUs into a safe state while the primary CPU executes
 a modified BL3-1 initialization, as described below.
 
-#### Architectural initialization
-
-As the first image to execute in this configuration BL3-1 must ensure that
-interconnect coherency is enabled (if required) before enabling the MMU.
-
 #### Platform initialization
 
 In this configuration, when the CPU resets to BL3-1 there are no parameters
@@ -962,7 +958,7 @@ The sample crash output is shown below.
 ---------------------------------
 
 Trusted Firmware implements a framework that allows CPU and platform ports to
-perform actions immediately after a CPU is released from reset in both the cold
+perform actions very early after a CPU is released from reset in both the cold
 and warm boot paths. This is done by calling the `reset_handler()` function in
 both the BL1 and BL3-1 images. It in turn calls the platform and CPU specific
 reset handling functions.
@@ -971,33 +967,12 @@ Details for implementing a CPU specific reset handler can be found in
 Section 8. Details for implementing a platform specific reset handler can be
 found in the [Porting Guide](see the `plat_reset_handler()` function).
 
-When adding functionality to a reset handler, the following points should be
-kept in mind.
-
-1.   The first reset handler in the system exists either in a ROM image
-     (e.g. BL1), or BL3-1 if `RESET_TO_BL31` is true. This may be detected at
-     compile time using the constant `FIRST_RESET_HANDLER_CALL`.
-
-2.   When considering ROM images, it's important to consider non TF-based ROMs
-     and ROMs based on previous versions of the TF code.
-
-3.   If the functionality should be applied to a ROM and there is no possibility
-     of a ROM being used that does not apply the functionality (or equivalent),
-     then the functionality should be applied within a `#if
-     FIRST_RESET_HANDLER_CALL` block.
-
-4.   If the functionality should execute in BL3-1 in order to override or
-     supplement a ROM version of the functionality, then the functionality
-     should be applied in the `#else` part of a `#if FIRST_RESET_HANDLER_CALL`
-     block.
-
-5.   If the functionality should be applied to a ROM but there is a possibility
-     of ROMs being used that do not apply the functionality, then the
-     functionality should be applied outside of a `FIRST_RESET_HANDLER_CALL`
-     block, so that BL3-1 has an opportunity to apply the functionality instead.
-     In this case, additional code may be needed to cope with different ROMs
-     that do or do not apply the functionality.
-
+When adding functionality to a reset handler, keep in mind that if a different
+reset handling behavior is required between the first and the subsequent
+invocations of the reset handling code, this should be detected at runtime.
+In other words, the reset handler should be able to detect whether an action has
+already been performed and act as appropriate. Possible courses of actions are,
+e.g. skip the action the second time, or undo/redo it.
 
 8.  CPU specific operations framework
 -----------------------------

docs/porting-guide.md

@@ -434,7 +434,7 @@ This function fulfills requirement 1 and 3 listed above.
 This function is called with the MMU and data caches disabled. It is responsible
 for placing the executing secondary CPU in a platform-specific state until the
 primary CPU performs the necessary actions to bring it out of that state and
-allow entry into the OS.
+allow entry into the OS. This function must not return.
 
 In the ARM FVP port, each secondary CPU powers itself off. The primary CPU is
 responsible for powering up the secondary CPU when normal world software
@@ -569,7 +569,7 @@ preserve the values of callee saved registers x19 to x29.
 
 The default implementation doesn't do anything. If a platform needs to override
 the default implementation, refer to the [Firmware Design] for general
-guidelines regarding placement of code in a reset handler.
+guidelines.
 
 ### Function : plat_disable_acp()
 

docs/user-guide.md

@@ -320,6 +320,10 @@ performed.
 *   `BL33_KEY`: This option is used when `GENERATE_COT=1`. It specifies the
     file that contains the BL3-3 private key in PEM format.
 
+*   `PROGRAMMABLE_RESET_ADDRESS`: This option indicates whether the reset
+    vector address can be programmed or is fixed on the platform. It can take
+    either 0 (fixed) or 1 (programmable). Default is 0.
+
 #### ARM development platform specific build options
 
 *   `ARM_TSP_RAM_LOCATION`: location of the TSP binary. Options:

include/common/asm_macros.S

@@ -99,41 +99,6 @@
 	.size \_name, . - \_name
 	.endm
 
-	/* ---------------------------------------------
-	 * Find the type of reset and jump to handler
-	 * if present. If the handler is null then it is
-	 * a cold boot. The primary cpu will set up the
-	 * platform while the secondaries wait for
-	 * their turn to be woken up
-	 * ---------------------------------------------
-	 */
-	.macro wait_for_entrypoint
-wait_for_entrypoint:
-	mrs	x0, mpidr_el1
-	bl	platform_get_entrypoint
-	cbnz	x0, do_warm_boot
-	mrs	x0, mpidr_el1
-	bl	platform_is_primary_cpu
-	cbnz	x0, do_cold_boot
-
-	/* ---------------------------------------------
-	 * Perform any platform specific secondary cpu
-	 * actions
-	 * ---------------------------------------------
-	 */
-	bl	plat_secondary_cold_boot_setup
-	b	wait_for_entrypoint
-
-	do_warm_boot:
-	/* ---------------------------------------------
-	 * Jump to BL31 for all warm boot init.
-	 * ---------------------------------------------
-	 */
-	blr	x0
-
-	do_cold_boot:
-	.endm
-
 	/*
 	 * This macro declares an array of 1 or more stacks, properly
 	 * aligned and in the requested section

include/common/bl_common.h

@@ -90,18 +90,6 @@
 	(_p)->h.attr = (uint32_t)(_attr) ; \
 	} while (0)
 
-/*******************************************************************************
- * Constant that indicates if this is the first version of the reset handler
- * contained in an image. This will be the case when the image is BL1 or when
- * its BL3-1 and RESET_TO_BL31 is true. This constant enables a subsequent
- * version of the reset handler to perform actions that override the ones
- * performed in the first version of the code. This will be required when the
- * first version exists in an un-modifiable image e.g. a BootROM image.
- ******************************************************************************/
-#if IMAGE_BL1 || (IMAGE_BL31 && RESET_TO_BL31)
-#define FIRST_RESET_HANDLER_CALL
-#endif
-
 #ifndef __ASSEMBLY__
 #include <cdefs.h> /* For __dead2 */
 #include <cassert.h>
@@ -195,9 +183,9 @@ typedef struct image_info {
  * This structure represents the superset of information that can be passed to
  * BL31 e.g. while passing control to it from BL2. The BL32 parameters will be
  * populated only if BL2 detects its presence. A pointer to a structure of this
- * type should be passed in X3 to BL31's cold boot entrypoint
+ * type should be passed in X0 to BL3-1's cold boot entrypoint.
  *
- * Use of this structure and the X3 parameter is not mandatory: the BL3-1
+ * Use of this structure and the X0 parameter is not mandatory: the BL3-1
  * platform code can use other mechanisms to provide the necessary information
  * about BL3-2 and BL3-3 to the common and SPD code.
  *

include/common/el3_common_macros.S

+/*
+ * 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.
+ */
+
+#ifndef __EL3_COMMON_MACROS_S__
+#define __EL3_COMMON_MACROS_S__
+
+#include <arch.h>
+#include <asm_macros.S>
+
+	/*
+	 * Helper macro to initialise EL3 registers we care about.
+	 */
+	.macro el3_arch_init_common _exception_vectors
+	/* ---------------------------------------------------------------------
+	 * 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_el3
+	orr	x0, x0, x1
+	msr	sctlr_el3, x0
+	isb
+
+#if IMAGE_BL31
+	/* ---------------------------------------------------------------------
+	 * Initialise the per-cpu cache pointer to the CPU.
+	 * This is done early to enable crash reporting to have access to crash
+	 * stack. Since crash reporting depends on cpu_data to report the
+	 * unhandled exception, not doing so can lead to recursive exceptions
+	 * due to a NULL TPIDR_EL3.
+	 * ---------------------------------------------------------------------
+	 */
+	bl	init_cpu_data_ptr
+#endif /* IMAGE_BL31 */
+
+	/* ---------------------------------------------------------------------
+	 * Set the exception vectors.
+	 * ---------------------------------------------------------------------
+	 */
+	adr	x0, \_exception_vectors
+	msr	vbar_el3, x0
+	isb
+
+	/* ---------------------------------------------------------------------
+	 * Enable the SError interrupt now that the exception vectors have been
+	 * setup.
+	 * ---------------------------------------------------------------------
+	 */
+	msr	daifclr, #DAIF_ABT_BIT
+
+	/* ---------------------------------------------------------------------
+	 * The initial state of the Architectural feature trap register
+	 * (CPTR_EL3) is unknown and it must be set to a known state. All
+	 * feature traps are disabled. Some bits in this register are marked as
+	 * reserved and should not be modified.
+	 *
+	 * CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1
+	 *  or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2.
+	 *
+	 * CPTR_EL3.TTA: This causes access to the Trace functionality to trap
+	 *  to EL3 when executed from EL0, EL1, EL2, or EL3. If system register
+	 *  access to trace functionality is not supported, this bit is RES0.
+	 *
+	 * CPTR_EL3.TFP: This causes instructions that access the registers
+	 *  associated with Floating Point and Advanced SIMD execution to trap
+	 *  to EL3 when executed from any exception level, unless trapped to EL1
+	 *  or EL2.
+	 * ---------------------------------------------------------------------
+	 */
+	mrs	x0, cptr_el3
+	bic	w0, w0, #TCPAC_BIT
+	bic	w0, w0, #TTA_BIT
+	bic	w0, w0, #TFP_BIT
+	msr	cptr_el3, x0
+	.endm
+
+/* -----------------------------------------------------------------------------
+ * This is the super set of actions that need to be performed during a cold boot
+ * or a warm boot in EL3. This code is shared by BL1 and BL3-1.
+ *
+ * This macro will always perform reset handling, architectural initialisations
+ * and stack setup. The rest of the actions are optional because they might not
+ * be needed, depending on the context in which this macro is called. This is
+ * why this macro is parameterised ; each parameter allows to enable/disable
+ * some actions.
+ *
+ *  _set_endian:
+ *	Whether the macro needs to configure the endianness of data accesses.
+ *
+ *  _warm_boot_mailbox:
+ *	Whether the macro needs to detect the type of boot (cold/warm). The
+ *	detection is based on the platform entrypoint address : if it is zero
+ *	then it is a cold boot, otherwise it is a warm boot. In the latter case,
+ *	this macro jumps on the platform entrypoint address.
+ *
+ *  _secondary_cold_boot:
+ *	Whether the macro needs to identify the CPU that is calling it: primary
+ *	CPU or secondary CPU. The primary CPU will be allowed to carry on with
+ *	the platform initialisations, while the secondaries will be put in a
+ *	platform-specific state in the meantime.
+ *
+ *	If the caller knows this macro will only be called by the primary CPU
+ *	then this parameter can be defined to 0 to skip this step.
+ *
+ * _init_memory:
+ *	Whether the macro needs to initialise the memory.
+ *
+ * _init_c_runtime:
+ *	Whether the macro needs to initialise the C runtime environment.
+ *
+ * _exception_vectors:
+ *	Address of the exception vectors to program in the VBAR_EL3 register.
+ * -----------------------------------------------------------------------------
+ */
+	.macro el3_entrypoint_common					\
+		_set_endian, _warm_boot_mailbox, _secondary_cold_boot,	\
+		_init_memory, _init_c_runtime, _exception_vectors
+
+	.if \_set_endian
+		/* -------------------------------------------------------------
+		 * Set the CPU endianness before doing anything that might
+		 * involve memory reads or writes.
+		 * -------------------------------------------------------------
+		 */
+		mrs	x0, sctlr_el3
+		bic	x0, x0, #SCTLR_EE_BIT
+		msr	sctlr_el3, x0
+		isb
+	.endif /* _set_endian */
+
+	.if \_warm_boot_mailbox
+		/* -------------------------------------------------------------
+		 * This code will be executed for both warm and cold resets.
+		 * Now is the time to distinguish between the two.
+		 * Query the platform entrypoint address and if it is not zero
+		 * then it means it is a warm boot so jump to this address.
+		 * -------------------------------------------------------------
+		 */
+		mrs	x0, mpidr_el1
+		bl	platform_get_entrypoint
+		cbz	x0, do_cold_boot
+		br	x0
+
+	do_cold_boot:
+	.endif /* _warm_boot_mailbox */
+
+	.if \_secondary_cold_boot
+		/* -------------------------------------------------------------
+		 * It is a cold boot.
+		 * The primary CPU will set up the platform while the
+		 * secondaries are placed in a platform-specific state until the
+		 * primary CPU performs the necessary actions to bring them out
+		 * of that state and allows entry into the OS.
+		 * -------------------------------------------------------------
+		 */
+		mrs	x0, mpidr_el1
+		bl	platform_is_primary_cpu
+		cbnz	x0, do_primary_cold_boot
+
+		/* This is a cold boot on a secondary CPU */
+		bl	plat_secondary_cold_boot_setup
+		/* plat_secondary_cold_boot_setup() is not supposed to return */
+	secondary_panic:
+		b	secondary_panic
+
+	do_primary_cold_boot:
+	.endif /* _secondary_cold_boot */
+
+	/* ---------------------------------------------------------------------
+	 * Perform any processor specific actions upon reset e.g. cache, TLB
+	 * invalidations etc.
+	 * ---------------------------------------------------------------------
+	 */
+	bl	reset_handler
+
+	el3_arch_init_common \_exception_vectors
+
+	.if \_init_memory
+		bl	platform_mem_init
+	.endif /* _init_memory */
+
+	/* ---------------------------------------------------------------------
+	 * Init C runtime environment:
+	 *   - Zero-initialise the NOBITS sections. There are 2 of them:
+	 *       - the .bss section;
+	 *       - the coherent memory section (if any).
+	 *   - Relocate the data section from ROM to RAM, if required.
+	 * ---------------------------------------------------------------------
+	 */
+	.if \_init_c_runtime
+		ldr	x0, =__BSS_START__
+		ldr	x1, =__BSS_SIZE__
+		bl	zeromem16
+
+#if USE_COHERENT_MEM
+		ldr	x0, =__COHERENT_RAM_START__
+		ldr	x1, =__COHERENT_RAM_UNALIGNED_SIZE__
+		bl	zeromem16
+#endif
+
+#ifdef __DATA_ROM_START__
+		ldr	x0, =__DATA_RAM_START__
+		ldr	x1, =__DATA_ROM_START__
+		ldr	x2, =__DATA_SIZE__
+		bl	memcpy16
+#endif
+	.endif /* _init_c_runtime */
+
+#if IMAGE_BL31
+	/* ---------------------------------------------------------------------
+	 * Use SP_EL0 for the C runtime stack.
+	 * ---------------------------------------------------------------------
+	 */
+	msr	spsel, #0
+#endif /* IMAGE_BL31 */
+
+	/* ---------------------------------------------------------------------
+	 * 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.
+	 * ---------------------------------------------------------------------
+	 */
+	mrs	x0, mpidr_el1
+	bl	platform_set_stack
+	.endm
+
+#endif /* __EL3_COMMON_MACROS_S__ */

plat/arm/board/fvp/fvp_bl31_setup.c

@@ -45,13 +45,13 @@ void bl31_early_platform_setup(bl31_params_t *from_bl2,
 	 * No need for locks as no other CPU is active.
 	 */
 	fvp_cci_init();
-#if RESET_TO_BL31
+
 	/*
-	 * Enable CCI coherency for the primary CPU's cluster
-	 * (if earlier BL has not already done so).
+	 * Enable CCI coherency for the primary CPU's cluster.
+	 * Earlier bootloader stages might already do this (e.g. Trusted
+	 * Firmware's BL1 does it) but we can't assume so. There is no harm in
+	 * executing this code twice anyway.
 	 * FVP PSCI code will enable coherency for other clusters.
 	 */
 	fvp_cci_enable();
-
-#endif /* RESET_TO_BL31 */
 }

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

@@ -42,10 +42,6 @@
 	/* --------------------------------------------------------------------
 	 * void plat_reset_handler(void);
 	 *
-	 * Before adding code in this function, refer to the guidelines in
-	 * docs/firmware-design.md to determine whether the code should reside
-	 * within the FIRST_RESET_HANDLER_CALL block or not.
-	 *
 	 * For Juno r0:
 	 * - Implement workaround for defect id 831273 by enabling an event
 	 *   stream every 65536 cycles.
@@ -58,13 +54,9 @@
 	 * - The default value for the L2 Tag RAM latency for Cortex-A57 is
 	 *   suitable.
 	 * - Defect #831273 doesn't affect Juno r1.
-	 *
-	 * This code is included only when FIRST_RESET_HANDLER_CALL is defined
-	 * since it should be executed only during BL1.
 	 * --------------------------------------------------------------------
 	 */
 func plat_reset_handler
-#ifdef FIRST_RESET_HANDLER_CALL
 	/* --------------------------------------------------------------------
 	 * Determine whether this code is running on Juno r0 or Juno r1.
 	 * Keep this information in x2.
@@ -123,6 +115,5 @@ apply_831273:
 	msr     CNTKCTL_EL1, x0
 ret:
 	isb
-#endif /* FIRST_RESET_HANDLER_CALL */
 	ret
 endfunc plat_reset_handler

plat/arm/common/arm_bl31_setup.c

@@ -179,16 +179,16 @@ void bl31_early_platform_setup(bl31_params_t *from_bl2,
 	 * No need for locks as no other CPU is active.
 	 */
 	arm_cci_init();
-#if RESET_TO_BL31
+
 	/*
-	 * Enable CCI coherency for the primary CPU's cluster
-	 * (if earlier BL has not already done so).
+	 * Enable CCI coherency for the primary CPU's cluster.
+	 * Earlier bootloader stages might already do this (e.g. Trusted
+	 * Firmware's BL1 does it) but we can't assume so. There is no harm in
+	 * executing this code twice anyway.
 	 * Platform specific PSCI code will enable coherency for other
 	 * clusters.
 	 */
 	cci_enable_snoop_dvm_reqs(MPIDR_AFFLVL1_VAL(read_mpidr()));
-
-#endif /* RESET_TO_BL31 */
 }
 
 /*******************************************************************************

services/std_svc/psci/psci_entry.S

 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2015, 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:
@@ -30,6 +30,7 @@
 
 #include <arch.h>
 #include <asm_macros.S>
+#include <el3_common_macros.S>
 #include <psci.h>
 #include <xlat_tables.h>
 
@@ -52,69 +53,30 @@ psci_aff_suspend_finish_entry:
 	adr	x23, psci_afflvl_suspend_finishers
 
 psci_aff_common_finish_entry:
-#if !RESET_TO_BL31
-	/* ---------------------------------------------
-	 * Perform any processor specific actions which
-	 * undo or are in addition to the actions
-	 * performed by the reset handler in the BootROM
-	 * (BL1) e.g. cache, tlb invalidations, errata
-	 * workarounds etc.
-	 * ---------------------------------------------
-	 */
-	bl      reset_handler
-
-	/* ---------------------------------------------
-	 * Enable the instruction cache, stack pointer
-	 * and data access alignment checks.
-	 * It can be assumed that BL3-1 entrypoint code
-	 * will do this when RESET_TO_BL31 is set. The
-	 * same  assumption cannot be made when another
-	 * boot loader executes before BL3-1 in the warm
-	 * boot path e.g. BL1.
-	 * ---------------------------------------------
-	 */
-	mov	x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
-	mrs	x0, sctlr_el3
-	orr	x0, x0, x1
-	msr	sctlr_el3, x0
-	isb
-#endif
-
-	/* ---------------------------------------------
-	 * Initialise the pcpu cache pointer for the CPU
-	 * ---------------------------------------------
-	 */
-	bl	init_cpu_data_ptr
-
-	/* ---------------------------------------------
-	 * Set the exception vectors
-	 * ---------------------------------------------
-	 */
-	adr	x0, runtime_exceptions
-	msr	vbar_el3, x0
-	isb
-
-	/* ---------------------------------------------
-	 * Enable the SError interrupt now that the
-	 * exception vectors have been setup.
-	 * ---------------------------------------------
-	 */
-	msr	daifclr, #DAIF_ABT_BIT
-
-	/* ---------------------------------------------
-	 * Use SP_EL0 for the C runtime stack.
-	 * ---------------------------------------------
-	 */
-	msr	spsel, #0
-
-	/* --------------------------------------------
-	 * Give ourselves a stack whose memory will be
-	 * marked as Normal-IS-WBWA when the MMU is
-	 * enabled.
-	 * --------------------------------------------
+	/*
+	 * On the warm boot path, most of the EL3 initialisations performed by
+	 * 'el3_entrypoint_common' must be skipped:
+	 *
+	 *  - Only when the platform bypasses the BL1/BL3-1 entrypoint by
+	 *    programming the reset address do we need to set the CPU endianness.
+	 *    In other cases, we assume this has been taken care by the
+	 *    entrypoint code.
+	 *
+	 *  - No need to determine the type of boot, we know it is a warm boot.
+	 *
+	 *  - Do not try to distinguish between primary and secondary CPUs, this
+	 *    notion only exists for a cold boot.
+	 *
+	 *  - No need to initialise the memory or the C runtime environment,
+	 *    it has been done once and for all on the cold boot path.
 	 */
-	mrs	x0, mpidr_el1
-	bl	platform_set_stack
+	el3_entrypoint_common					\
+		_set_endian=PROGRAMMABLE_RESET_ADDRESS		\
+		_warm_boot_mailbox=0				\
+		_secondary_cold_boot=0				\
+		_init_memory=0					\
+		_init_c_runtime=0				\
+		_exception_vectors=runtime_exceptions
 
 	/* --------------------------------------------
 	 * Enable the MMU with the DCache disabled. It