Commit Graph

536 Commits

Author SHA1 Message Date
danh-arm b110f61a37 Merge pull request #203 from danh-arm/dh/misc-docs-1.0
Miscellaneous documentation fixes
2014-08-27 19:16:27 +01:00
Sandrine Bailleux 4480425288 Miscellaneous documentation fixes
This patch gathers miscellaneous minor fixes to the documentation, and comments
in the source code.

Change-Id: I631e3dda5abafa2d90f464edaee069a1e58b751b
Co-Authored-By: Soby Mathew <soby.mathew@arm.com>
Co-Authored-By: Dan Handley <dan.handley@arm.com>
2014-08-27 19:13:56 +01:00
danh-arm ae5bb9db5a Merge pull request #202 from achingupta/ag/fw-design-juno-update
Add information about Juno in firmware-design.md
2014-08-27 18:27:19 +01:00
Juan Castillo 2442d24865 Add information about Juno in firmware-design.md
This patch reorganizes the firmware design guide to add information about the
port of the ARM Trusted Firmware to the Juno ARM development platform.

Change-Id: I0b80e2e7a35ccad1af2e971506cfb7fe505f8b84
2014-08-27 17:57:35 +01:00
danh-arm e40ae239f8 Merge pull request #200 from danh-arm/dh/fix-reset-to-bl31-part2
Fix reset to BL3-1 instructions in user guide, part 2
2014-08-27 17:26:30 +01:00
danh-arm 21387b8f73 Merge pull request #201 from danh-arm/jc/juno-user-guide
Add Juno instructions to user guide
2014-08-27 17:25:50 +01:00
Juan Castillo d14e0acf99 Add Juno instructions to user guide
This patch makes the Trusted Firmware build instructions in the
user guide platform independent.

FVP specific instructions have been grouped together under a new
section dedicated to FVP.

Juno specific instructions to build and run the Trusted Firmware,
UEFI and Linux have been added.

Change-Id: I9bfb1b9d732b1f73abbe29f68ac931e1773a4fd5
2014-08-27 15:21:58 +01:00
Dan Handley 7ea4c43772 Fix reset to BL3-1 instructions in user guide, part 2
Fix the instructions for resetting to the BL3-1 entrypoint in the
user guide. The BL3-1 and BL3-2 image locations changed in the fix
to ARM-software/tf-issues#100 (commit 186c1d4). This is distinct
from the similar issue fixed in commit bfb1dd5.

Also clarify the dependence on the FVP_SHARED_DATA_LOCATION and
FVP_TSP_RAM_LOCATION build options, and tidy up the "Notes
regarding Base FVP configuration options" section.

Change-Id: I6b03452a71f0c69efa169852712bcb184242696e
2014-08-27 11:58:52 +01:00
danh-arm 17f89d084a Merge pull request #198 from danh-arm/dh/move-up-dependencies
Move up dependency versions in user guide
2014-08-21 18:30:31 +01:00
danh-arm 4ed74d02e0 Merge pull request #197 from soby-mathew/rationalize_uarts
Rationalize UART usage among different BL stages
2014-08-21 16:44:40 +01:00
Soby Mathew 12d554f941 Rationalize UART usage among different BL stages
This patch changes the UART port assignment for various BL stages
so as to make it consistent on the platform ports. The BL1, BL2 and
BL3-1 now uses UART0 on the FVP port and SoC UART0 on the Juno port.
The BL3-2 uses UART2 on the FVP port and FPGA UART0 on the Juno
port.

This provides an interim fix to ARM-software/tf-issues#220 until
support is added for changing the UART port for a BL image between
cold boot and runtime.

Change-Id: Iae5faea90be3d59e41e597b34a902f93e737505a
2014-08-21 16:30:25 +01:00
Dan Handley ba73bb098c Move up dependency versions in user guide
Move up the version numbers of the following Trusted Firmware
dependencies in the user guide:

*   Foundation and Base FVPs (latest publically available
    versions).

*   EDK2 implementation. The guide now uses the latest version from
    https://github.com/ARM-software/edk2.git. This requires the
    `iasl` package to also be installed.

*   Linux kernel. The guide now uses the latest version from
    https://github.com/ARM-software/linux.git.

*   Linaro OpenEmbedded file system.

*   ARM Development Studio 5.

Change-Id: I95bb863a61e47b9ef8be3d110f7087375ee78add
2014-08-21 16:18:17 +01:00
danh-arm e434cf1aa3 Merge pull request #196 from soby-mathew/sm/tf_juno_support
Add support for Juno in Trusted Firmware
2014-08-21 15:15:49 +01:00
Juan Castillo 38af430af6 Juno: Read primary CPU MPID from SCC GPR_1
This patch removes the PRIMARY_CPU definition hardcoded in the
Juno port. Instead, the primary CPU is obtained at runtime by
reading the SCC General Purpose Register 1 (GPR_1), whose value
is copied by the SCP into shared memory during the boot process.

Change-Id: I3981daa92eb7142250712274cf7f655b219837f5
2014-08-21 14:53:48 +01:00
Juan Castillo efafbc898e Juno: Implement PSCI SYSTEM_OFF and SYSTEM_RESET APIs
This patch adds the Juno platform specific handlers for PSCI
SYSTEM_OFF and SYSTEM_RESET operations.

Change-Id: Ie389adead533ec2314af44d721b4d0f306147c7d
2014-08-21 14:53:48 +01:00
Sandrine Bailleux edfda10a6b Juno: Add support for Test Secure-EL1 Payload
This patch implements the TSP on Juno. It executes from on-chip Trusted
SRAM.

Also, the other bootloader images (i.e. BL1 R/W, BL2 and BL3-1) have
been moved around. The reason is, although there was enough space
overall to store the TSP in SRAM, there was no contiguous free chunk
of SRAM big enough to hold it.

This patch keeps the overall memory layout (i.e. keeping BL1 R/W at
the bottom, BL2 at the top and BL3-1 in between) but moves the base
addresses of all the bootloader images in such a way that:
 - memory fragmentation is reduced enough to fit BL3-2 in;
 - new base addresses are suitable for release builds as well as debug
   ones;
 - each image has a few extra kilobytes for future growth.
   BL3-1 and BL3-2 are the images which received the biggest allocations
   since they will most probably grow the most.

This patch also adds instruction synchronization barriers around the code which
handles the timer interrupt in the TSP. This ensures that the interrupt is not
acknowledged after or EOIed before it is deactivated at the peripheral.

Change-Id: I1c5b51858700027ee283ac85d18e06863a27c72e
2014-08-21 14:53:48 +01:00
Achin Gupta fef4fdb9cc Juno: Implement PSCI CPU_OFF and CPU_SUSPEND APIs
This patch adds support for PSCI CPU_OFF and CPU_SUSPEND APIs to the Juno port
of the ARM Trusted Firmware. The maximum affinity level that can be suspended is
the cluster level (affinity level 1). Support for suspending the system level is
not present.

Change-Id: Ie2c9da0acd7d1b0d5ac64940cdf40347153e52c8
2014-08-21 14:53:48 +01:00
Sandrine Bailleux 01b916bff2 Juno: Implement initial platform port
This patch adds the initial port of the ARM Trusted Firmware on the Juno
development platform. This port does not support a BL3-2 image or any PSCI APIs
apart from PSCI_VERSION and PSCI_CPU_ON. It enables workarounds for selected
Cortex-A57 (#806969 & #813420) errata and implements the workaround for a Juno
platform errata (Defect id 831273).

Change-Id: Ib3d92df3af53820cfbb2977582ed0d7abf6ef893
2014-08-21 14:53:48 +01:00
danh-arm e822d7c1c7 Merge pull request #195 from achingupta/ag/fvp_dt_updates
FVP: Update device trees to match cpuidle driver
2014-08-20 20:15:16 +01:00
danh-arm 7963671c04 Merge pull request #194 from danh-arm/sm/tf-issues#98
Implement the CPU Specific operations framework v3
2014-08-20 20:14:59 +01:00
Achin Gupta bab7bfd282 FVP: Update device trees to match cpuidle driver
This patch updates the representation of idle tables and cpu/cluster topology in
the device tree source files for the FVP to what the latest cpuidle driver in
Linux expects. The device tree binaries have also been updated.

Change-Id: If0668b96234f65aa0435fba52f288c9378bd8824
2014-08-20 19:38:58 +01:00
Soby Mathew 3fd5ddfeb0 Add documentation for CPU specific abstraction and Errata workarounds
This patch adds documentation for CPU specific abstraction in the firmware-
design.md and adds a new document cpu-errata-workarounds.md to describe
the cpu errata workaround build flags.

Change-Id: Ia08c2fec0b868a0a107d0264e87a60182797a1bd
2014-08-20 19:14:32 +01:00
Soby Mathew d9bdaf2d98 Add support for selected Cortex-A57 errata workarounds
This patch adds workarounds for selected errata which affect the Cortex-A57 r0p0
part. Each workaround has a build time flag which should be used by the platform
port to enable or disable the corresponding workaround. The workarounds are
disabled by default. An assertion is raised if the platform enables a workaround
which does not match the CPU revision at runtime.

Change-Id: I9ae96b01c6ff733d04dc733bd4e67dbf77b29fb0
2014-08-20 19:14:31 +01:00
Soby Mathew d3f70af6e0 Add CPU specific crash reporting handlers
This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.

Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab
2014-08-20 19:14:31 +01:00
Soby Mathew add403514d Add CPU specific power management operations
This patch adds CPU core and cluster power down sequences to the CPU specific
operations framework introduced in a earlier patch. Cortex-A53, Cortex-A57 and
generic AEM sequences have been added. The latter is suitable for the
Foundation and Base AEM FVPs. A pointer to each CPU's operations structure is
saved in the per-cpu data so that it can be easily accessed during power down
seqeunces.

An optional platform API has been introduced to allow a platform to disable the
Accelerator Coherency Port (ACP) during a cluster power down sequence. The weak
definition of this function (plat_disable_acp()) does not take any action. It
should be overriden with a strong definition if the ACP is present on a
platform.

Change-Id: I8d09bd40d2f528a28d2d3f19b77101178778685d
2014-08-20 19:14:31 +01:00
Soby Mathew 24fb838f96 Add platform API for reset handling
This patch adds an optional platform API (plat_reset_handler) which allows the
platform to perform any actions immediately after a cold or warm reset
e.g. implement errata workarounds. The function is called with MMU and caches
turned off. This API is weakly defined and does nothing by default but can be
overriden by a platform with a strong definition.

Change-Id: Ib0acdccbd24bc756528a8bd647df21e8d59707ff
2014-08-20 19:14:31 +01:00
Soby Mathew 9b47684170 Introduce framework for CPU specific operations
This patch introduces a framework which will allow CPUs to perform
implementation defined actions after a CPU reset, during a CPU or cluster power
down, and when a crash occurs. CPU specific reset handlers have been implemented
in this patch. Other handlers will be implemented in subsequent patches.

Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.

Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956
2014-08-20 19:13:25 +01:00
Soby Mathew aecc084080 Rework use of labels in assembly macros.
This patch provides a workaround for the ASM_ASSERT label issue
and also reworks the use of labels in assembly macros.
If the caller of the ASM_ASSERT macro happened to use the
label '1' to jump past the ASM_ASSERT macro, it would not have
worked since the ASM_ASSERT macro internally used the same label.
Hence, as a workaround, this patch makes the label a high
number in the expectation that the caller will never use it.

Also updated the other assembly macros using numerical labels to
named lables.

Change-Id: Iec892359db84f2391ad2a83a92141c4d7049776a
2014-08-19 14:42:35 +01:00
Achin Gupta a4a8eaeb36 Miscellaneous PSCI code cleanups
This patch implements the following cleanups in PSCI generic code:

1. It reworks the affinity level specific handlers in the PSCI implementation
   such that.

   a. Usage of the 'rc' local variable is restricted to only where it is
      absolutely needed

   b. 'plat_state' local variable is defined only when a direct invocation of
      plat_get_phys_state() does not suffice.

   c. If a platform handler is not registered then the level specific handler
      returns early.

2. It limits the use of the mpidr_aff_map_nodes_t typedef to declaration of
   arrays of the type instead of using it in function prototypes as well.

3. It removes dangling declarations of __psci_cpu_off() and
   __psci_cpu_suspend(). The definitions of these functions were removed in
   earlier patches.

Change-Id: I51e851967c148be9c2eeda3a3c41878f7b4d6978
2014-08-19 14:29:23 +01:00
Achin Gupta 7d2ccfd79d fvp: Rework when platform actions are performed
This patch reworks FVP port's power management implementation to perform
platform actions only when the platform exported hook is invoked for the highest
affinity level to enter/exit the OFF state.

For example, during a CPU_OFF operation, fvp_affinst_off() is called twice: for
affinity level 0 and affinity level 1 (in that order). CPU specific operations
are deferred until the next invocation if it is determined through a call to
psci_get_max_phys_off_afflvl() that this is CPU is the last in the cluster.

Similarly, during power up if the CPU is the first in the cluster, both CPU and
cluster specific operations are performed when fvp_affinst_on_finish() is
invoked for affinity level 1. Earlier, they were done across the two invocations
of the handler.

Change-Id: I4288ed3ba1385db36a69cc2e598deb219f209b8a
2014-08-19 14:29:23 +01:00
Achin Gupta 0a46e2c340 Add APIs to preserve highest affinity level in OFF state
This patch adds APIs to find, save and retrieve the highest affinity level which
will enter or exit from the physical OFF state during a PSCI power management
operation. The level is stored in per-cpu data.

It then reworks the PSCI implementation to perform cache maintenance only
when the handler for the highest affinity level to enter/exit the OFF state is
called.

For example. during a CPU_SUSPEND operation, state management is done prior to
calling the affinity level specific handlers. The highest affinity level which
will be turned off is determined using the psci_find_max_phys_off_afflvl()
API. This level is saved using the psci_set_max_phys_off_afflvl() API. In the
code that does generic handling for each level, prior to performing cache
maintenance it is first determined if the current affinity level matches the
value returned by psci_get_max_phys_off_afflvl(). Cache maintenance is done if
the values match.

This change allows the last CPU in a cluster to perform cache maintenance
independently. Earlier, cache maintenance was started in the level 0 handler and
finished in the level 1 handler. This change in approach will facilitate
implementation of tf-issues#98.

Change-Id: I57233f0a27b3ddd6ddca6deb6a88b234525b0ae6
2014-08-19 14:29:23 +01:00
Achin Gupta 84c9f1003c Rework state management in the PSCI implementation
This patch pulls out state management from the affinity level specific handlers
into the top level functions specific to the operation
i.e. psci_afflvl_suspend(), psci_afflvl_on() etc.

In the power down path this patch will allow an affinity instance at level X to
determine the state that an affinity instance at level X+1 will enter before the
level specific handlers are called. This will be useful to determine whether a
CPU is the last in the cluster during a suspend/off request and so on.

Similarly, in the power up path this patch will allow an affinity instance at
level X to determine the state that an affinity instance at level X+1 has
emerged from, even after the level specific handlers have been called. This will
be useful in determining whether a CPU is the first in the cluster during a
on/resume request and so on.

As before, while powering down, state is updated before the level specific
handlers are invoked so that they can perform actions based upon their target
state. While powering up, state is updated after the level specific handlers have
been invoked so that they can perform actions based upon the state they emerged
from.

Change-Id: I40fe64cb61bb096c66f88f6d493a1931243cfd37
2014-08-19 14:29:23 +01:00
Achin Gupta 776b68ae59 Add PSCI service specific per-CPU data
This patch adds a structure defined by the PSCI service to the per-CPU data
array. The structure is used to save the 'power_state' parameter specified
during a 'cpu_suspend' call on the current CPU. This parameter was being saved
in the cpu node in the PSCI topology tree earlier.

The existing API to return the state id specified during a PSCI CPU_SUSPEND call
i.e. psci_get_suspend_stateid(mpidr) has been renamed to
psci_get_suspend_stateid_by_mpidr(mpidr). The new psci_get_suspend_stateid() API
returns the state id of the current cpu.

The psci_get_suspend_afflvl() API has been changed to return the target affinity
level of the current CPU. This was specified using the 'mpidr' parameter in the
old implementation.

The behaviour of the get_power_on_target_afflvl() has been tweaked such that
traversal of the PSCI topology tree to locate the affinity instance node for the
current CPU is done only in the debug build as it is an expensive operation.

Change-Id: Iaad49db75abda471f6a82d697ee6e0df554c4caf
2014-08-19 14:29:23 +01:00
Achin Gupta 04fafcee2b Add macro to flush per-CPU data
This patch adds a macro which will flush the contents of the specified member of
the per-CPU data structure to the PoC. This is required to enable an update of a
per-CPU data member to be visible to all observers.

Change-Id: I20e0feb9b9f345dc5a1162e88adc7956a7ad7a64
2014-08-19 14:29:23 +01:00
danh-arm f139a39a61 Merge pull request #191 from danh-arm/jc/tf-issues/218
Add support for PSCI SYSTEM_OFF and SYSTEM_RESET APIs v2
2014-08-19 11:48:38 +01:00
Juan Castillo d5f1309306 Add support for PSCI SYSTEM_OFF and SYSTEM_RESET APIs
This patch adds support for SYSTEM_OFF and SYSTEM_RESET PSCI
operations. A platform should export handlers to complete the
requested operation. The FVP port exports fvp_system_off() and
fvp_system_reset() as an example.

If the SPD provides a power management hook for system off and
system reset, then the SPD is notified about the corresponding
operation so it can do some bookkeeping. The TSPD exports
tspd_system_off() and tspd_system_reset() for that purpose.

Versatile Express shutdown and reset methods have been removed
from the FDT as new PSCI sys_poweroff and sys_reset services
have been added. For those kernels that do not support yet these
PSCI services (i.e. GICv3 kernel), the original dtsi files have
been renamed to *-no_psci.dtsi.

Fixes ARM-software/tf-issues#218

Change-Id: Ic8a3bf801db979099ab7029162af041c4e8330c8
2014-08-19 11:42:45 +01:00
Dan Handley a1d80440c4 Merge pull request #189 from achingupta/ag/tf-issues#153
Unmask SError interrupt and clear SCR_EL3.EA bit
2014-08-19 11:04:21 +01:00
Dan Handley 57a18ff489 Merge pull request #181 from danh-arm/dh/tsp_fvp_dependency
Move TSP private declarations into separate header
Clarify platform porting interface to TSP
2014-08-19 11:03:01 +01:00
Dan Handley 5a06bb7e0b Clarify platform porting interface to TSP
* Move TSP platform porting functions to new file:
  include/bl32/tsp/platform_tsp.h.

* Create new TSP_IRQ_SEC_PHY_TIMER definition for use by the generic
  TSP interrupt handling code, instead of depending on the FVP
  specific definition IRQ_SEC_PHY_TIMER.

* Rename TSP platform porting functions from bl32_* to tsp_*, and
  definitions from BL32_* to TSP_*.

* Update generic TSP code to use new platform porting function names
  and definitions.

* Update FVP port accordingly and move all TSP source files to:
  plat/fvp/tsp/.

* Update porting guide with above changes.

Note: THIS CHANGE REQUIRES ALL PLATFORM PORTS OF THE TSP TO
      BE UPDATED

Fixes ARM-software/tf-issues#167

Change-Id: Ic0ff8caf72aebb378d378193d2f017599fc6b78f
2014-08-19 10:55:54 +01:00
Achin Gupta 0c8d4fef28 Unmask SError interrupt and clear SCR_EL3.EA bit
This patch disables routing of external aborts from lower exception levels to
EL3 and ensures that a SError interrupt generated as a result of execution in
EL3 is taken locally instead of a lower exception level.

The SError interrupt is enabled in the TSP code only when the operation has not
been directly initiated by the normal world. This is to prevent the possibility
of an asynchronous external abort which originated in normal world from being
taken when execution is in S-EL1.

Fixes ARM-software/tf-issues#153

Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
2014-08-15 10:21:50 +01:00
Dan Handley da0af78aa2 Move TSP private declarations into separate header
Move the TSP private declarations out of tsp.h and into a new
header, tsp_private.h. This clarifies the TSP interface to the TSPD.

Change-Id: I39af346eeba3350cadcac56c02d97a5cb978c28b
2014-08-14 11:25:41 +01:00
danh-arm e98f414b2f Merge pull request #187 from danh-arm/dh/refactor-drivers
Refactor platform porting interface to drivers v2
2014-08-14 11:22:47 +01:00
Dan Handley 3279f6251e Simplify interface to TZC-400 driver
The TZC-400 driver previously allowed the possibility of multiple
controller instances to be present in the same executable. This
was unnecessary since there will only ever be one instance.

This change simplifies the tzc_init() function to only take the
base address argument needed by implementation, conforming to the
driver initialization model of other drivers. It also hides some
of the implementation details that were previously exposed by the
API.

The FVP port has been updated accordingly.

THIS CHANGE REQUIRES ALL PLATFORM PORTS THAT USE THE TZC-400
DRIVER TO BE UPDATED

Fixes ARM-software/tf-issues#181

Change-Id: I7b721edf947064989958d8f457d6462d92e742c8
2014-08-14 11:17:52 +01:00
Dan Handley 935db69328 Move IO storage source to drivers directory
Move the remaining IO storage source file (io_storage.c) from the
lib to the drivers directory. This requires that platform ports
explicitly add this file to the list of source files.

Also move the IO header files to a new sub-directory, include/io.

Change-Id: I862b1252a796b3bcac0d93e50b11e7fb2ded93d6
2014-08-14 11:17:03 +01:00
Dan Handley 6d16ce0bfe Remove redundant io_init() function
The intent of io_init() was to allow platform ports to provide
a data object (io_plat_data_t) to the IO storage framework to
allocate into. The abstraction was incomplete because io_plat_data_t
uses a platform defined constant and the IO storage framework
internally allocates other arrays using platform defined constants.

This change simplifies the implementation by instantiating the
supporting objects in the IO storage framework itself. There is now
no need for the platform to call io_init().

The FVP port has been updated accordingly.

THIS CHANGE REQUIRES ALL PLATFORM PORTS THAT USE THE IO STORAGE
FRAMEWORK TO BE UDPATED.

Change-Id: Ib48ac334de9e538064734334c773f8b43df3a7dc
2014-08-14 11:16:15 +01:00
Dan Handley cae3ef992e Remove platform dependency in CCI-400 driver
* Create cci_init() function in CCI-400 driver to allow platform
  to provide arguments needed by the driver (i.e. base address
  and cluster indices for the ACE slave interfaces).

* Rename cci_(en|dis)able_coherency to
  cci_(en|dis)able_cluster_coherency to make it clear that
  the driver only enables/disables the coherency of CPU
  clusters and not other devices connected to the CCI-400.

* Update FVP port to use new cci_init() function and remove
  unnecessary CCI defintions from platform_def.h. Also rename
  fvp_cci_setup() to fvp_cci_enable() to more clearly
  differentiate between CCI initialization and enabling.

THIS CHANGE REQUIRES PLATFORM PORTS THAT USE THE CCI-400 DRIVER
TO BE UPDATED

Fixes ARM-software/tf-issues#168

Change-Id: I1946a51409b91217b92285b6375082619f607fec
2014-08-14 10:49:20 +01:00
danh-arm f0e240d7f5 Merge pull request #184 from jcastillo-arm/jc/tf-issues/100
FVP: make usage of Trusted DRAM optional at build time
2014-08-14 09:52:22 +01:00
danh-arm 233020911d Merge pull request #186 from danh-arm/dh/fix-reset-to-bl31
Fix reset to BL3-1 instructions in user guide
2014-08-14 09:50:45 +01:00
Juan Castillo 186c1d4b26 FVP: make usage of Trusted DRAM optional at build time
This patch groups the current contents of the Trusted DRAM region at
address 0x00_0600_0000 (entrypoint mailboxes and BL3-1 parameters) in
a single shared memory area that may be allocated to Trusted SRAM
(default) or Trusted DRAM at build time by setting the
FVP_SHARED_DATA_LOCATION make variable. The size of this shared
memory is 4096 bytes.

The combination 'Shared data in Trusted SRAM + TSP in Trusted DRAM'
is not currently supported due to restrictions in the maximum number
of mmu tables that can be created.

Documentation has been updated to reflect these changes.

Fixes ARM-software/tf-issues#100

Change-Id: I26ff04d33ce4cacf8d770d1a1e24132b4fc53ff0
2014-08-14 09:32:48 +01:00
Dan Handley bfb1dd51c0 Fix reset to BL3-1 instructions in user guide
Fix the instructions for resetting to the BL3-1 entrypoint in the
user guide. The BL3-1 and BL3-2 image locations changed in the fix
to ARM-software/tf-issues#117 (commit a1b6db6).

Fixes ARM-software/tf-issues#237

Change-Id: I764eb17c66034511efb984c0e7cfda29bd99198f
2014-08-13 12:06:42 +01:00