1QEMU virt Armv8-A
2=================
3
4Trusted Firmware-A (TF-A) implements the EL3 firmware layer for QEMU virt
5Armv8-A. BL1 is used as the BootROM, supplied with the -bios argument.
6When QEMU starts all CPUs are released simultaneously, BL1 selects a
7primary CPU to handle the boot and the secondaries are placed in a polling
8loop to be released by normal world via PSCI.
9
10BL2 edits the Flattened Device Tree, FDT, generated by QEMU at run-time to
11add a node describing PSCI and also enable methods for the CPUs.
12
13If ``ARM_LINUX_KERNEL_AS_BL33`` is set to 1 then this FDT will be passed to BL33
14via register x0, as expected by a Linux kernel. This allows a Linux kernel image
15to be booted directly as BL33 rather than using a bootloader.
16
17An ARM64 defconfig v5.5 Linux kernel is known to boot, FDT doesn't need to be
18provided as it's generated by QEMU.
19
20Current limitations:
21
22-  Only cold boot is supported
23
24Getting non-TF images
25---------------------
26
27``QEMU_EFI.fd`` can be downloaded from
28http://snapshots.linaro.org/components/kernel/leg-virt-tianocore-edk2-upstream/latest/QEMU-KERNEL-AARCH64/RELEASE_GCC5/QEMU_EFI.fd
29
30or, can be built as follows:
31
32.. code:: shell
33
34    git clone https://github.com/tianocore/edk2.git
35    cd edk2
36    git submodule update --init
37    make -C BaseTools
38    source edksetup.sh
39    export GCC5_AARCH64_PREFIX=aarch64-linux-gnu-
40    build -a AARCH64 -t GCC5 -p ArmVirtPkg/ArmVirtQemuKernel.dsc
41
42````
43
44Then, you will get ``Build/ArmVirtQemuKernel-AARCH64/DEBUG_GCC5/FV/QEMU_EFI.fd``
45
46Please note you do not need to use GCC 5 in spite of the environment variable
47``GCC5_AARCH64_PREFIX``
48
49The rootfs can be built by using Buildroot as follows:
50
51.. code:: shell
52
53    git clone git://git.buildroot.net/buildroot.git
54    cd buildroot
55    make qemu_aarch64_virt_defconfig
56    utils/config -e BR2_TARGET_ROOTFS_CPIO
57    utils/config -e BR2_TARGET_ROOTFS_CPIO_GZIP
58    make olddefconfig
59    make
60
61Then, you will get ``output/images/rootfs.cpio.gz``.
62
63Booting via semi-hosting option
64-------------------------------
65
66Boot binaries, except BL1, are primarily loaded via semi-hosting so all
67binaries has to reside in the same directory as QEMU is started from. This
68is conveniently achieved with symlinks the local names as:
69
70-  ``bl2.bin`` -> BL2
71-  ``bl31.bin`` -> BL31
72-  ``bl33.bin`` -> BL33 (``QEMU_EFI.fd``)
73-  ``Image`` -> linux/arch/arm64/boot/Image
74
75To build:
76
77.. code:: shell
78
79    make CROSS_COMPILE=aarch64-none-elf- PLAT=qemu
80
81To start (QEMU v5.0.0):
82
83.. code:: shell
84
85    qemu-system-aarch64 -nographic -machine virt,secure=on -cpu cortex-a57  \
86        -kernel Image                           \
87        -append "console=ttyAMA0,38400 keep_bootcon"   \
88        -initrd rootfs.cpio.gz -smp 2 -m 1024 -bios bl1.bin   \
89        -d unimp -semihosting-config enable,target=native
90
91Booting via flash based firmwares
92---------------------------------
93
94Boot firmwares are loaded via secure FLASH0 device so ``bl1.bin`` and
95``fip.bin`` should be concatenated to create a ``flash.bin`` that is flashed
96onto secure FLASH0.
97
98-  ``bl32.bin`` -> BL32 (``tee-header_v2.bin``)
99-  ``bl32_extra1.bin`` -> BL32 Extra1 (``tee-pager_v2.bin``)
100-  ``bl32_extra2.bin`` -> BL32 Extra2 (``tee-pageable_v2.bin``)
101-  ``bl33.bin`` -> BL33 (``QEMU_EFI.fd``)
102-  ``Image`` -> linux/arch/arm64/boot/Image
103
104To build:
105
106.. code:: shell
107
108    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=qemu BL32=bl32.bin \
109        BL32_EXTRA1=bl32_extra1.bin BL32_EXTRA2=bl32_extra2.bin \
110        BL33=bl33.bin BL32_RAM_LOCATION=tdram SPD=opteed all fip
111
112To build with TBBR enabled, BL31 and BL32 encrypted with test key:
113
114.. code:: shell
115
116    make CROSS_COMPILE=aarch64-linux-gnu- PLAT=qemu BL32=bl32.bin \
117        BL32_EXTRA1=bl32_extra1.bin BL32_EXTRA2=bl32_extra2.bin \
118        BL33=bl33.bin BL32_RAM_LOCATION=tdram SPD=opteed all fip \
119        MBEDTLS_DIR=<path-to-mbedtls-repo> TRUSTED_BOARD_BOOT=1 \
120        GENERATE_COT=1 DECRYPTION_SUPPORT=aes_gcm FW_ENC_STATUS=0 \
121        ENCRYPT_BL31=1 ENCRYPT_BL32=1
122
123To build flash.bin:
124
125.. code:: shell
126
127    dd if=build/qemu/release/bl1.bin of=flash.bin bs=4096 conv=notrunc
128    dd if=build/qemu/release/fip.bin of=flash.bin seek=64 bs=4096 conv=notrunc
129
130To start (QEMU v5.0.0):
131
132.. code:: shell
133
134    qemu-system-aarch64 -nographic -machine virt,secure=on -cpu cortex-a57  \
135        -kernel Image -no-acpi                     \
136        -append 'console=ttyAMA0,38400 keep_bootcon'  \
137        -initrd rootfs.cpio.gz -smp 2 -m 1024 -bios flash.bin   \
138        -d unimp
139
140Running QEMU in OpenCI
141-----------------------
142
143Linaro's continuous integration platform OpenCI supports running emulated tests
144on QEMU. The tests are kicked off on Jenkins and deployed through the Linaro
145Automation and Validation Architecture `LAVA`_.
146
147There are a set of Linux boot tests provided in OpenCI. They rely on prebuilt
148`binaries`_ for UEFI, the kernel, root file system, as well as, any other TF-A
149dependencies, and are run as part of the OpenCI TF-A `daily job`_. To run them
150manually, a `builder`_ job may be triggered with the test configuration
151``qemu-boot-tests``.
152
153
154You may see the following warning repeated several times in the boot logs:
155
156.. code:: shell
157
158    pflash_write: Write to buffer emulation is flawed
159
160Please ignore this as it is an unresolved `issue in QEMU`_, it is an internal
161QEMU warning that logs flawed use of "write to buffer".
162
163.. note::
164    For more information on how to trigger jobs in OpenCI, please refer to
165    Linaro's CI documentation, which explains how to trigger a `manual job`_.
166
167.. _binaries: https://downloads.trustedfirmware.org/tf-a/linux_boot/
168.. _daily job: https://ci.trustedfirmware.org/view/TF-A/job/tf-a-main/
169.. _builder: https://ci.trustedfirmware.org/view/TF-A/job/tf-a-builder/
170.. _LAVA: https://tf.validation.linaro.org/
171.. _manual job: https://tf-ci-users-guide.readthedocs.io/en/latest/#manual-job-trigger
172.. _issue in QEMU: https://git.qemu.org/?p=qemu.git;a=blob;f=hw/block/pflash_cfi01.c;h=0cbc2fb4cbf62c9a033b8dd89012374ff74ed610;hb=refs/heads/master#l500
173