Merge pull request #1381 from antonio-nino-diaz-arm/an/kernel-boot

plat/arm: Introduce ARM_LINUX_KERNEL_AS_BL33 build option
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Dimitris Papastamos 2018-05-16 14:26:28 +01:00 committed by GitHub
commit dcf1a04e3b
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3 changed files with 122 additions and 28 deletions

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@ -607,7 +607,7 @@ Common build options
firmware images have been loaded in memory, and the MMU and caches are
turned off. Refer to the "Debugging options" section for more details.
- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
secure interrupts (caught through the FIQ line). Platforms can enable
this directive if they need to handle such interruption. When enabled,
the FIQ are handled in monitor mode and non secure world is not allowed
@ -695,6 +695,15 @@ Arm development platform specific build options
Trusted Watchdog may be disabled at build time for testing or development
purposes.
- ``ARM_LINUX_KERNEL_AS_BL33``: The Linux kernel expects registers x0-x3 to
have specific values at boot. This boolean option allows the Trusted Firmware
to have a Linux kernel image as BL33 by preparing the registers to these
values before jumping to BL33. This option defaults to 0 (disabled). For now,
it only supports AArch64 kernels. ``RESET_TO_BL31`` must be 1 when using it.
If this option is set to 1, ``ARM_PRELOADED_DTB_BASE`` must be set to the
location of a device tree blob (DTB) already loaded in memory. The Linux
Image address must be specified using the ``PRELOADED_BL33_BASE`` option.
- ``ARM_RECOM_STATE_ID_ENC``: The PSCI1.0 specification recommends an encoding
for the construction of composite state-ID in the power-state parameter.
The existing PSCI clients currently do not support this encoding of
@ -1492,41 +1501,92 @@ without a BL33 and prepare to jump to a BL33 image loaded at address
make PRELOADED_BL33_BASE=0x80000000 PLAT=fvp all fip
Boot of a preloaded bootwrapped kernel image on Base FVP
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Boot of a preloaded kernel image on Base FVP
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The following example uses the AArch64 boot wrapper. This simplifies normal
world booting while also making use of TF-A features. It can be obtained from
its repository with:
The following example uses a simplified boot flow by directly jumping from the
TF-A to the Linux kernel, which will use a ramdisk as filesystem. This can be
useful if both the kernel and the device tree blob (DTB) are already present in
memory (like in FVP).
For example, if the kernel is loaded at ``0x80080000`` and the DTB is loaded at
address ``0x82000000``, the firmware can be built like this:
::
git clone git://git.kernel.org/pub/scm/linux/kernel/git/mark/boot-wrapper-aarch64.git
CROSS_COMPILE=aarch64-linux-gnu- \
make PLAT=fvp DEBUG=1 \
RESET_TO_BL31=1 \
ARM_LINUX_KERNEL_AS_BL33=1 \
PRELOADED_BL33_BASE=0x80080000 \
ARM_PRELOADED_DTB_BASE=0x82000000 \
all fip
After compiling it, an ELF file is generated. It can be loaded with the
following command:
Now, it is needed to modify the DTB so that the kernel knows the address of the
ramdisk. The following script generates a patched DTB from the provided one,
assuming that the ramdisk is loaded at address ``0x84000000``. Note that this
script assumes that the user is using a ramdisk image prepared for U-Boot, like
the ones provided by Linaro. If using a ramdisk without this header,the ``0x40``
offset in ``INITRD_START`` has to be removed.
.. code:: bash
#!/bin/bash
# Path to the input DTB
KERNEL_DTB=<path-to>/<fdt>
# Path to the output DTB
PATCHED_KERNEL_DTB=<path-to>/<patched-fdt>
# Base address of the ramdisk
INITRD_BASE=0x84000000
# Path to the ramdisk
INITRD=<path-to>/<ramdisk.img>
# Skip uboot header (64 bytes)
INITRD_START=$(printf "0x%x" $((${INITRD_BASE} + 0x40)) )
INITRD_SIZE=$(stat -Lc %s ${INITRD})
INITRD_END=$(printf "0x%x" $((${INITRD_BASE} + ${INITRD_SIZE})) )
CHOSEN_NODE=$(echo \
"/ { \
chosen { \
linux,initrd-start = <${INITRD_START}>; \
linux,initrd-end = <${INITRD_END}>; \
}; \
};")
echo $(dtc -O dts -I dtb ${KERNEL_DTB}) ${CHOSEN_NODE} | \
dtc -O dtb -o ${PATCHED_KERNEL_DTB} -
And the FVP binary can be run with the following command:
::
<path-to>/FVP_Base_AEMv8A-AEMv8A \
-C bp.secureflashloader.fname=bl1.bin \
-C bp.flashloader0.fname=fip.bin \
-a cluster0.cpu0=<bootwrapped-kernel.elf> \
--start cluster0.cpu0=0x0
<path-to>/FVP_Base_AEMv8A-AEMv8A \
-C pctl.startup=0.0.0.0 \
-C bp.secure_memory=1 \
-C cluster0.NUM_CORES=4 \
-C cluster1.NUM_CORES=4 \
-C cache_state_modelled=1 \
-C cluster0.cpu0.RVBAR=0x04020000 \
-C cluster0.cpu1.RVBAR=0x04020000 \
-C cluster0.cpu2.RVBAR=0x04020000 \
-C cluster0.cpu3.RVBAR=0x04020000 \
-C cluster1.cpu0.RVBAR=0x04020000 \
-C cluster1.cpu1.RVBAR=0x04020000 \
-C cluster1.cpu2.RVBAR=0x04020000 \
-C cluster1.cpu3.RVBAR=0x04020000 \
--data cluster0.cpu0="<path-to>/bl31.bin"@0x04020000 \
--data cluster0.cpu0="<path-to>/<patched-fdt>"@0x82000000 \
--data cluster0.cpu0="<path-to>/<kernel-binary>"@0x80080000 \
--data cluster0.cpu0="<path-to>/<ramdisk.img>"@0x84000000
The ``-a cluster0.cpu0=<bootwrapped-kernel.elf>`` option loads the ELF file. It
also sets the PC register to the ELF entry point address, which is not the
desired behaviour, so the ``--start cluster0.cpu0=0x0`` option forces the PC back
to 0x0 (the BL1 entry point address) on CPU #0. The ``PRELOADED_BL33_BASE`` define
used when compiling the FIP must match the ELF entry point.
Boot of a preloaded kernel image on Juno
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Boot of a preloaded bootwrapped kernel image on Juno
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The procedure to obtain and compile the boot wrapper is very similar to the case
of the FVP. The execution must be stopped at the end of bl2\_main(), and the
loading method explained above in the EL3 payload boot flow section may be used
to load the ELF file over JTAG on Juno.
The Trusted Firmware must be compiled in a similar way as for FVP explained
above. The process to load binaries to memory is the one explained in
`Booting an EL3 payload on Juno`_.
Running the software on FVP
---------------------------

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@ -81,7 +81,7 @@ void arm_bl31_early_platform_setup(bl31_params_t *from_bl2, uintptr_t soc_fw_con
assert(from_bl2 == NULL);
assert(plat_params_from_bl2 == NULL);
#ifdef BL32_BASE
# ifdef BL32_BASE
/* Populate entry point information for BL32 */
SET_PARAM_HEAD(&bl32_image_ep_info,
PARAM_EP,
@ -90,7 +90,7 @@ void arm_bl31_early_platform_setup(bl31_params_t *from_bl2, uintptr_t soc_fw_con
SET_SECURITY_STATE(bl32_image_ep_info.h.attr, SECURE);
bl32_image_ep_info.pc = BL32_BASE;
bl32_image_ep_info.spsr = arm_get_spsr_for_bl32_entry();
#endif /* BL32_BASE */
# endif /* BL32_BASE */
/* Populate entry point information for BL33 */
SET_PARAM_HEAD(&bl33_image_ep_info,
@ -106,6 +106,19 @@ void arm_bl31_early_platform_setup(bl31_params_t *from_bl2, uintptr_t soc_fw_con
bl33_image_ep_info.spsr = arm_get_spsr_for_bl33_entry();
SET_SECURITY_STATE(bl33_image_ep_info.h.attr, NON_SECURE);
# if ARM_LINUX_KERNEL_AS_BL33
/*
* According to the file ``Documentation/arm64/booting.txt`` of the
* Linux kernel tree, Linux expects the physical address of the device
* tree blob (DTB) in x0, while x1-x3 are reserved for future use and
* must be 0.
*/
bl33_image_ep_info.args.arg0 = (u_register_t)ARM_PRELOADED_DTB_BASE;
bl33_image_ep_info.args.arg1 = 0U;
bl33_image_ep_info.args.arg2 = 0U;
bl33_image_ep_info.args.arg3 = 0U;
# endif
#else /* RESET_TO_BL31 */
/*

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@ -80,6 +80,27 @@ ARM_XLAT_TABLES_LIB_V1 := 0
$(eval $(call assert_boolean,ARM_XLAT_TABLES_LIB_V1))
$(eval $(call add_define,ARM_XLAT_TABLES_LIB_V1))
# Don't have the Linux kernel as a BL33 image by default
ARM_LINUX_KERNEL_AS_BL33 := 0
$(eval $(call assert_boolean,ARM_LINUX_KERNEL_AS_BL33))
$(eval $(call add_define,ARM_LINUX_KERNEL_AS_BL33))
ifeq (${ARM_LINUX_KERNEL_AS_BL33},1)
ifneq (${ARCH},aarch64)
$(error "ARM_LINUX_KERNEL_AS_BL33 is only available in AArch64.")
endif
ifneq (${RESET_TO_BL31},1)
$(error "ARM_LINUX_KERNEL_AS_BL33 is only available if RESET_TO_BL31=1.")
endif
ifndef PRELOADED_BL33_BASE
$(error "PRELOADED_BL33_BASE must be set if ARM_LINUX_KERNEL_AS_BL33 is used.")
endif
ifndef ARM_PRELOADED_DTB_BASE
$(error "ARM_PRELOADED_DTB_BASE must be set if ARM_LINUX_KERNEL_AS_BL33 is used.")
endif
$(eval $(call add_define,ARM_PRELOADED_DTB_BASE))
endif
# Use an implementation of SHA-256 with a smaller memory footprint but reduced
# speed.
$(eval $(call add_define,MBEDTLS_SHA256_SMALLER))