Re: How to boot FreeBSD for arm 32 bit as DomU with u-boot on my ARM Chromebook
- In reply to: Mario Marietto : "Re: How to boot FreeBSD for arm 32 bit as DomU with u-boot on my ARM Chromebook"
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Date: Tue, 19 Dec 2023 17:07:40 UTC
....I see that some other interesting files have been produced by u-boot when I have compiled it : u-boot u-boot.lds u-boot.bin u-boot.map u-boot-nodtb.bin u-boot.dtb u-boot.srec u-boot-dtb.bin u-boot.sym So,maybe I should use a different u-boot* file for booting FreeBSD ? On Tue, Dec 19, 2023 at 4:28 PM Mario Marietto <marietto2008@gmail.com> wrote: > Hello to everyone. > > I have compiled the needed u-boot.bin from scratch using this procedure : > > # git clone https://github.com/u-boot/u-boot.git > # cd u-boot > # ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make snow_defconfig : this > line generates the file .config > # nano .config and I've added these parameters : > > CONFIG_ARMV7_NONSEC=n > CONFIG_EFI_GRUB_ARM32_WORKAROUND=y > > the uboot-bin file is generated with this command : > > # ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make > > At this point,I took a look inside the .config file and I saw that the > parameter "CONFIG_ARMV7_NONSEC=n" has been removed. So,for some reason,it > is not accepted and this could be a problem.... > > These are the xen config files that I've used : > > nano freebsd.cfg > > name="test" > kernel="u-boot.bin" > extra = "console=hvc0" > memory=256 > vcpus=1 > disk = [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ] > > nano start-freebsd > > xl create freebsd.cfg > xl console freebsd > > This is what happens when I launch the vm : > > # ./start-freebsd > > Parsing config from freebsd.cfg > xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader found: > Invalid kernel > libxl: error: libxl_dom.c:571:libxl__build_dom: xc_dom_parse_image failed > libxl: error: libxl_create.c:1640:domcreate_rebuild_done: Domain 1:cannot > (re-)build domain: -3 > libxl: error: libxl_domain.c:1183:libxl__destroy_domid: Domain > 1:Non-existent domain > libxl: error: libxl_domain.c:1137:domain_destroy_callback: Domain 1:Unable > to destroy guest > libxl: error: libxl_domain.c:1064:domain_destroy_cb: Domain 1:Destruction > of domain failed > freebsd is an invalid domain identifier (rc=-6) > > > On Mon, Dec 18, 2023 at 12:39 PM Mario Marietto <marietto2008@gmail.com> > wrote: > >> So,ok,I should have said "the second u-boot" ; since the first u-boot >> binary is the "u-boot binary located in the RO memory" of the Chromebook". >> Sorry for the confusion. >> >> On Mon, Dec 18, 2023 at 12:35 PM Mario Marietto <marietto2008@gmail.com> >> wrote: >> >>> ---> There are no specific options in u-boot devoted to FreeBSD >>> >>> This is an important factor. So,what about if,instead of compiling a new >>> version of u-boot on the partition 2,I will recompile the u-boot customized >>> version created by the virtual open system in 2014,that should be installed >>> on the first partition ? It could work if there are no differences between >>> the u-boot that should boot Linux and the u-boot that should boot FreeBSD. >>> >>> Can you give a look at the u-boot source code created by virtual open >>> systems ? You can find it on my google drive : >>> >>> >>> https://drive.google.com/file/d/1eAaZMfd6CU0xiqQfH7sq5wGVzzO09BRm/view?usp=sharing >>> >>> I need to understand if I can recompile it without problem so that it >>> can satisfy my needs (the ability of the file u-boot.bin to boot FreeBSD as >>> domU under Xen,as explained by Stefano Stabellini,the xen developer that >>> suggested to me what I could do to have FreeBSD virtualized under Xen on my >>> Arm Chromebook) ; otherwise the risk is to find later problems that will >>> make me troubles and that I will not able to fix. >>> >>> I gave a look at the virtual open system u-boot and I didn't see any arndale_defconfig >>> inside. So,If I have understood correctly,I should put that file inside the >>> root of the u-boot source code,let's say here : >>> >>> marietto:/home/marietto/Desktop/Files/u-boot_FreeBSD/u-boot-vos # ls >>> >>> .checkpatch.conf README doc >>> net >>> .git api drivers >>> onenand_ipl >>> .gitignore arch dts >>> post >>> COPYING board examples >>> rules.mk >>> CREDITS boards.cfg fs >>> scripts >>> MAINTAINERS common include >>> snapshot.commit >>> MAKEALL config.mk lib >>> spl >>> Makefile cros mkconfig >>> test >>> PRESUBMIT.cfg disk nand_spl >>> tools >>> >>> and I should do : make and make install ? and the file I need,u-boot.bin >>> will be generated ? >>> >>> I didn't find any pre made configuration file inside : >>> >>> u-boot-vos # find . -type f -name "exynos*" >>> >>> ./include/exynos-fb.h >>> ./include/configs/exynos5-common.h >>> ./doc/device-tree-bindings/spi/exynos-spi.txt >>> ./doc/device-tree-bindings/usb/exynos-usb.txt >>> ./drivers/power/exynos-tmu.c >>> ./drivers/power/exynos-cpufreq.c >>> ./drivers/video/exynos-fb.c >>> ./drivers/spi/exynos_spi.c >>> ./board/samsung/dts/exynos5250-spring.dts >>> ./board/samsung/dts/exynos5250-smdk5250.dts >>> ./board/samsung/dts/exynos5250-snow.dts >>> ./board/samsung/dts/exynos5250-daisy.dts >>> ./arch/arm/include/asm/arch-exynos5/exynos-cpufreq.h >>> ./arch/arm/include/asm/arch-exynos5/exynos-tmu.h >>> ./arch/arm/dts/exynos5250.dtsi >>> ./arch/arm/dts/exynos-periph-id.dtsi >>> ./arch/arm/cpu/armv7/exynos5/exynos_cache.c >>> >>> u-boot-vos # find . -type f -name "arndale*" >>> >>> For sure I can't use a newer version of u-boot because otherwise the >>> patches needed to bypass the bootloader protections of the Arm Chromebook >>> (such as a lot of different patches needed to boot correctly Linux) will be >>> broken ; anyway,since it works,I don't need to use an updated version of >>> u-boot. >>> >>> ----> As per my experience, you have to respect these two options, >>> compiling u-boot for FreeBSD: >>> https://github.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-master/files/FreeBSD_Fragment >>> >>> It says that I should use these parameters : >>> >>> CONFIG_ARMV7_NONSEC=n >>> CONFIG_EFI_GRUB_ARM32_WORKAROUND=y >>> >>> These are the parameters used to configure a Linux kernel. I don't >>> understand what's the relation between the compilation of a linux kernel >>> and u-boot. In the past I tried to recompile u-boot,but I didn't have the >>> need to set up those parameters,so I don't know how to do it (but I know >>> how to recompile a Linux kernel). >>> >>> >>> ---> I'm not sure that I'm getting you right, as I don't understand what >>> you mean under "the first u-boot". >>> >>> >>> I'm talking about first u-boot because the whole procedure to boot Linux >>> on the ARM Chromebook,that's explained here : >>> >>> http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook/ >>> >>> >>> at some point they say : >>> >>> >>> To be able to run KVM on ARM platforms, the kernel has to be booted in >>> hypervisor mode. Because of this relatively recent requirement (due to the >>> introduction of the virtualization extensions), up until now all booting >>> methods would boot the kernel in the standard Supervisor mode. >>> >>> For the ARM Chromebook the default boot procedure doesn't allow us to >>> boot in hypervisor mode. Although the laptop's boot mechanism is based on >>> the frequently used u-boot, the binary is located in RO memory. >>> Fortunately, a chained u-boot mechanism can be used (i.e. starting another >>> u-boot after the original). We can then enter hypervisor mode from our >>> custom iteration of u-boot and subsequently load our kernel and userspace. >>> >>> So,the first u-boot is the u-boot provided by virtual open >>> systems,that's able to chainload the "u-boot binary located in RO memory" , >>> that does not boot Chrome OS in hypervisor mode. We don't need it if we >>> want to boot Linux with kvm or xen enabled. >>> >>> On Sun, Dec 17, 2023 at 1:28 AM Stanislav Silnicki < >>> stanislav.silnicki@mailgate.us> wrote: >>> >>>> I'm not an expert in the topic, I only know, that ARM has divided >>>> hardware into two worlds - Secure and Not-So, strictly limiting any >>>> software, running in non-secure world with access to functions and >>>> resources. >>>> https://developer.arm.com/documentation/den0013/d/Security/TrustZone-hardware-architecture?lang=en >>>> >>>> I'm not sure, that I'm getting you right, as I don't understand what >>>> you mean under "the first u-boot". >>>> >>>> As I understand, virtualization (HYP) is running in non-secure world ( >>>> https://developer.arm.com/documentation/ddi0406/c/System-Level-Architecture/The-System-Level-Programmers--Model/The-Virtualization-Extensions), >>>> so my guess (only guess!!!), virtualization software has to prepare >>>> (configure) HW platform in the way, that FreeBSD kernel will not lack any >>>> resources, required to configure MPU, VA, etc. >>>> So, if you lucky to boot virtualizer, which is aware of target OS, that >>>> maybe you can boot the kernel. Although, I doubt, that you need to boot >>>> 'second' u-boot to boot the kernel - there is simply ubldr, which you can >>>> hook somehow from virtualizer.... >>>> >>>> Stan >>>> >>>> >>>> >>>> Mario Marietto wrote: >>>> >>>> >>>> ---> As I understand, it makes sure that u-boot keeps in secure mode >>>> during boot and passes control to ubldr, which boots FreeBSD kernel, in >>>> that mode. >>>> >>>> Can you elaborate your sentence more ? I know that the bootloader >>>> secure mode is bypassed by the virtual open systems u-boot. Are you saying >>>> that when the control passes to the second u-boot,it will happen in secure >>>> mode,so that the bypass that happened loading the first u-boot,is annulled >>>> ? If this is true,maybe can I boot FreeBSD using the virtual-open-system >>>> custom u-boot ? Is this compatible with FreeBSD ? Where can I find the >>>> u-boot.bin that the xen developer talked about ? thanks bro'. >>>> >>>> >>>> >>>> On Sun, Dec 17, 2023 at 12:35 AM Stanislav Silnicki < >>>> stanislav.silnicki@mailgate.us> wrote: >>>> >>>>> Hi Mario, >>>>> >>>>> U-Boot beast is hiding in this den: >>>>> https://source.denx.de/u-boot/u-boot.git >>>>> I took a brief look at your post and it seems to me, that option >>>>> CONFIG_CMO_BY_VA_ONLY is irrelevant to your target armv7 32 bit >>>>> platform: >>>>> https://source.denx.de/u-boot/u-boot/-/blob/master/arch/arm/cpu/armv8/Kconfig?ref_type=heads#L3 >>>>> >>>>> As for compiling the u-boot, it is a doable task, given that you >>>>> understand what you are doing. There are no specific options in u-boot >>>>> devoted to FreeBSD. It is a boot loader, whose mission to make basic >>>>> hardware initialization, read you kernel file from some media into RAM and >>>>> then pass it control. >>>>> >>>>> Basically, you can grab some defconfig, prepared for any other >>>>> Exynos5250 based board (say, this one: >>>>> https://source.denx.de/u-boot/u-boot/-/blob/master/configs/arndale_defconfig?ref_type=heads) >>>>> and adopt it somehow. >>>>> >>>>> As per my experience, you have to respect these two options, compiling >>>>> u-boot for FreeBSD: >>>>> https://github.com/freebsd/freebsd-ports/blob/main/sysutils/u-boot-master/files/FreeBSD_Fragment >>>>> >>>>> As I understand, it makes sure, that u-boot keeps in secure mode >>>>> during boot and passes control to ubldr, which boots FreBSD kernel, in that >>>>> mode. Otherwise, there a lot of surprises you may realize. >>>>> >>>>> Hope, this will help to progress you tasks >>>>> Stan >>>>> >>>>> Mario Marietto wrote: >>>>> >>>>> >>>>> Hello. >>>>> >>>>> I'm trying to boot FreeBSD for arm32 bit as DomU on my ARM Chromebook. >>>>> Basically there are two ways to accomplish this task : >>>>> >>>>> 1) to write a patch that allows the FreeBSD kernel to boot as a zImage >>>>> file. This could be accomplished applying this patch to a specific file >>>>> that's on the source code of FreeBSD : >>>>> >>>>> >>>>> >>>>> https://xenbits.xen.org/gitweb/?p=p...8;hb=0782e25d98cc1391472717035f986c979edef0c9 >>>>> <https://xenbits.xen.org/gitweb/?p=people/julieng/freebsd.git;a=blob_plain;f=sys/arm/conf/XENVIRT;h=ff6433392e6fc2d5fa7c1ad1f7c40155003af9a8;hb=0782e25d98cc1391472717035f986c979edef0c9> >>>>> >>>>> >>>>> This patch was written by Julien Grall a lot of time ago and now it >>>>> does not work anymore. This is the reason : >>>>> >>>>> >>>>> It appears FreeBSD-CURRENT removed the last step converting the kernel >>>>> file to kernel.bin. The patch can be readily rebased, but without >>>>> kernel.bin that doesn't do too much. >>>>> >>>>> >>>>> >>>>> So,without a rebase of that patch the first option is not applicable. >>>>> And I'm not able to fix it. >>>>> >>>>> 2) booting FreeBSD using U-Boot,as explained to me by a xen developer : >>>>> >>>>> >>>>> I was trying to explain why and how Julien's patch works so that you >>>>> could be the one to re-do something similar or fix the patch on the FreeBSD >>>>> kernel that you are working with. I am happy to help review and write >>>>> patches but I don't work with the FreeBSD kernel so I wouldn't be able to >>>>> help you quickly. However, I might have a suggestion. Do you know if >>>>> FreeBSD can be booted by U-Boot ? Because U-Boot definitely boots as Xen on >>>>> ARM guest firmware/bootloader. You should be able to build U-Boot and use >>>>> the U-Boot binary as Xen guest kernel, then U-Boot could load FreeBSD from >>>>> disk or network and start it. For instance as domU config file: >>>>> >>>>> kernel="/home/petalinux/u-boot.bin" >>>>> disk = [ '/home/petalinux/test.img,raw,xvda' ] >>>>> >>>>> I know it is important to build u-boot with the following config to >>>>> make it work on Xen. >>>>> >>>>> CONFIG_CMO_BY_VA_ONLY=y >>>>> >>>>> >>>>> >>>>> This option seems more doable to me according to my knowledge. But I >>>>> need to understand how to do it. >>>>> >>>>> Well,let's say that on the ARM Chromebook I'm forced to use and >>>>> install a customized version of u-boot,created by virtual open >>>>> systems,because it is the only one that allows bypassing its bootloader >>>>> protection. You can find more information here : >>>>> >>>>> >>>>> http://www.virtualopensystems.com/en/solutions/guides/kvm-on-chromebook/?vos=tech >>>>> >>>>> This is the relevant section to read : >>>>> >>>>> >>>>> Bootloader : >>>>> >>>>> If you wish to skip this chapter you can download a pre-compiled >>>>> binary of the bootloader: >>>>> >>>>> >>>>> $ wget >>>>> http://www.virtualopensystems.com/downloads/guides/kvm_on_chromebook/nv_u-boot-snow.kpart >>>>> >>>>> >>>>> To be able to run KVM on ARM platforms, the kernel has to be booted in >>>>> hypervisor mode. Because of this relatively recent requirement (due to the >>>>> introduction of the virtualization extensions), up until now all booting >>>>> methods would boot the kernel in the standard Supervisor mode. For the ARM >>>>> Chromebook the default boot procedure doesn't allow us to boot in >>>>> hypervisor mode. Although the laptop's boot mechanism is based on the >>>>> frequently used u-boot, the binary is located in RO memory. Fortunately, a >>>>> chained u-boot mechanism can be used (i.e. starting another u-boot after >>>>> the original). We can then enter hypervisor mode from our custom iteration >>>>> of u-boot and subsequently load our kernel and userspace. >>>>> >>>>> Checkout the needed u-boot code : >>>>> >>>>> >>>>> $ git clone git://github.com/virtualopensystems/u-boot.git$ cd >>>>> u-boot$ ./scripts/build.sh >>>>> >>>>> >>>>> If successful, a message about how to copy the bootloader on the USB >>>>> flash disk or SD card will appear. We will use it later when preparing the >>>>> boot medium to start our system. If you have followed the Setting up the >>>>> boot medium chapter and you have a prepared boot device, then you can >>>>> update u-boot by running : >>>>> >>>>> >>>>> $ sudo dd if=nv_uboot-snow.kpart of=/dev/sdX1 >>>>> >>>>> >>>>> >>>>> so,the needed u-boot that we must use should be installed on the first >>>>> partition of the sd card. >>>>> >>>>> There is another relevant section to read : >>>>> >>>>> >>>>> Setting up the boot medium >>>>> >>>>> Now it is time to copy all the relevant files that we created in the >>>>> previous chapters,and use them to boot Chromebook with a different kernel >>>>> and OS. In all these examples the device /dev/sdX is used. Take extra care >>>>> to change the examples to the device that you have attached. Insert the >>>>> boot medium on your workstation and carefully execute the following step. >>>>> First we need to properly format the boot medium. >>>>> >>>>> In the uboot source directory : >>>>> >>>>> >>>>> $ sudo ./scripts/sdcard.sh /dev/sdX >>>>> >>>>> >>>>> This will erase all data and create 4 partitions in the medium, along >>>>> with copying the u-boot binary to the first partition: >>>>> >>>>> >>>>> Partition 1 = ChromeOS signed binary (V.O.S chained u-boot) >>>>> Partition 2 = not used >>>>> Partition 3 = EXT2 partition for u-boot files (uImage and >>>>> exynos5250-snow.dtb) >>>>> Partition 4 = EXT4 partition for userspace files >>>>> >>>>> >>>>> With u-boot being copied, next is the kernel image and DTB file. From >>>>> the kernel source execute : >>>>> >>>>> >>>>> $ mkdir ../mnt/ >>>>> $ sudo mount /dev/sdX3 ../mnt/ >>>>> $ sudo cp arch/arm/boot/uImage ../mnt/ >>>>> $ sudo cp arch/arm/boot/dts/exynos5250-snow.dtb ../mnt/ >>>>> $ sudo umount /dev/sdX3 >>>>> >>>>> >>>>> Finally, we have to copy the Ubuntu userspace filesystem that we >>>>> created earlier: >>>>> >>>>> >>>>> $ sudo mount /dev/sdX4 mnt/$ sudo cp -a ./precise/* mnt/$ sudo umount >>>>> /dev/sdX4 >>>>> >>>>> >>>>> >>>>> Now,my idea is to chainload the already chain loaded u-boot created by >>>>> V.O.S to the new u-boot that we need for booting FreeBSD and that can be >>>>> installed in the partition n.2,as shown in this scheme,because it is not >>>>> used : >>>>> >>>>> >>>>> Partition 1 = ChromeOS signed binary (V.O.S chained u-boot) >>>>> Partition 2 = not used (maybe we can install the u-boot for arm 32 >>>>> bit,compatible with FreeBSD on this partition) >>>>> Partition 3 = EXT2 partition for u-boot files (uImage and >>>>> exynos5250-snow.dtb) >>>>> Partition 4 = EXT4 partition for userspace files >>>>> >>>>> >>>>> Take in consideration that default boot string is hardcoded here,in >>>>> the snow.h file of the custom u-boot created by VOS : >>>>> >>>>> >>>>> >>>>> https://github.com/virtualopensyste...18a39b6c177dff58a/include/configs/snow.h#L101 >>>>> <https://github.com/virtualopensystems/u-boot/blob/eecfeb578e296ef3b739ac918a39b6c177dff58a/include/configs/snow.h#L101> >>>>> >>>>> >>>>> and it needs to be recompiled because it should point to the partition >>>>> n.2,where I will install the u-boot files as explained here : >>>>> >>>>> >>>>> https://wiki.freebsd.org/arm/Chromebook >>>>> >>>>> >>>>> I have some questions to ask before I start working on this. >>>>> >>>>> 1) The xen developer said : >>>>> >>>>> >>>>> You should be able to build U-Boot and use the U-Boot binary as Xen >>>>> guest kernel... >>>>> >>>>> >>>>> >>>>> where is the u-boot binary,according to this document ? >>>>> >>>>> https://wiki.freebsd.org/arm/Chromebook >>>>> >>>>> I don't see it. >>>>> >>>>> >>>>> 2) where is the source code of the file that I can get here : >>>>> >>>>> >>>>> http://commondatastorage.googleapis.com/chromeos-localmirror/distfiles/nv_uboot-snow-simplefb.kpart.bz2 >>>>> >>>>> I need the source code if I want to recompile u-boot so that it can >>>>> point to the partition 4. >>>>> >>>>> Maybe it can be found on this link : >>>>> >>>>> http://linux-exynos.org/dist/chromebook/nv_uboot/ >>>>> >>>>> but it can't be opened.... >>>>> >>>>> >>>>> 3) in this specific scenario the source code of u-boot should run on >>>>> arm 32 bit,not on arm 64,because I have the Samsung Chromebook "SNOW" model >>>>> XE303C12,that's powered by a Samsung Exynos 5250 (ARMv7 32 bit Cortex A15) >>>>> Soc. >>>>> >>>>> >>>>> 4) I'm not sure if I can chainload the customized u-boot created by >>>>> V.O.S that should be installed on the first partition with the u-boot >>>>> tailored for booting FreeBSD that should be installed on the partition 2.... >>>>> >>>>> >>>>> 5) the xen developer said that u-boot should be compiled enabling this >>>>> option : >>>>> >>>>> >>>>> Code: >>>>> >>>>> CONFIG_CMO_BY_VA_ONLY=y >>>>> >>>>> >>>>> >>>>> Well,can you provide some good source that can help me to understand >>>>> how I can recompile u-boot for FreeBSD ? thanks. >>>>> >>>>> -- >>>>> Mario. >>>>> >>>>> >>>> >>>> -- >>>> Mario. >>>> >>>> >>> >>> -- >>> Mario. >>> >> >> >> -- >> Mario. >> > > > -- > Mario. > -- Mario.