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: Thu, 28 Dec 2023 16:25:30 UTC
Hello. I'm trying to compile u-boot-2017.05 (because it can boot a 32-bit ARM board. It is an out-of-tree u-boot build that can execute the ubldr to boot FreeBSD. I found it here : https://src.fedoraproject.org/repo/pkgs/uboot-tools/u-boot-2017.05.tar.bz2/sha512/be270f9242a72b05463092a022bbabd54996762de1ff23bf7575124ac02e62f49572a4e2f6f571a5019047d40027e56e35593b5cc373c4a5a39b100c3377ba93/ It has been suggested to me by the U-Boot Xen maintainers. Infact one of them said : Yes, it can boot a 32-bit ARM board. I'm not a FreeBSD person, but I've helped a FreeBSD user booting a 32-bit ARM box with u-boot (GoFlexHome Marvell Kirkwood 6281). The u-boot version was 2017.05. I used an out-of-tree u-boot build. This u-boot executed the ubldr to boot FreeBSD. Please see here : https://forum.doozan.com/read.php?3,49039,82059#msg-82059 So. I tried to compile it directly on my ARM Chromebook,but it failed. And it also fails if compiled with "ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-" on my Ubuntu 23.04 x86_64 workstation : /Chromebook/freebsd-xen/domU-freebsd/bootloaders/u-boot-2017.05# make snow_defconfig HOSTCC scripts/basic/fixdep HOSTCC scripts/kconfig/conf.o HOSTCC scripts/kconfig/zconf.tab.o HOSTLD scripts/kconfig/conf # # configuration written to .config # /Chromebook/freebsd-xen/domU-freebsd/bootloaders/u-boot-2017.05# make scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config.h CFG u-boot.cfg GEN include/autoconf.mk GEN include/autoconf.mk.dep CFG spl/u-boot.cfg GEN spl/include/autoconf.mk CHK include/config/uboot.release CHK include/generated/version_autogenerated.h UPD include/generated/version_autogenerated.h CHK include/generated/timestamp_autogenerated.h UPD include/generated/timestamp_autogenerated.h CC lib/asm-offsets.s gcc: error: unrecognized -march target: armv5 gcc: note: valid arguments are: armv4 armv4t armv5t armv5te armv5tej armv6 armv6j armv6k armv6z armv6kz armv6zk armv6t2 armv6-m armv6s-m armv7 armv7-a armv7ve armv7-r armv7-m armv7e-m armv8-a armv8.1-a armv8.2-a armv8.3-a armv8.4-a armv8.5-a armv8.6-a armv8-m.base armv8-m.main armv8-r armv8.1-m.main armv9-a iwmmxt iwmmxt2 native; did you mean ‘armv4’? gcc: error: missing argument to ‘-march=’ make[1]: *** [Kbuild:44: lib/asm-offsets.s] Errore 1 make: *** [Makefile:1287: prepare0] Errore 2 What should I do to compile it succesfully ? On Sat, Dec 23, 2023 at 7:36 PM Mario Marietto <marietto2008@gmail.com> wrote: > > I've added this parameter to bootxen.source : > > guest_loglvl=all > > bootxen.source : > > mmc dev 1 > ext2load mmc 1:3 0x42000000 zImage-5.4.261-iommu-dma-on-xen > ext2load mmc 1:3 0x51000000 xen-4.17-armhf-armmp-0x51004000.ub > ext2load mmc 1:3 0x5ffec000 exynos5250-snow.dtb > fdt addr 0x5ffec000 > fdt resize 1024 > fdt set /chosen \#address-cells <0x2> > fdt set /chosen \#size-cells <0x2> > fdt set /chosen xen,xen-bootargs "console=dtuart dtuart=serial0 dom0_mem=1152M dom0_max_vcpus=2 bootscrub=0 vwfi=native guest_loglvl=all" > fdt mknod /chosen dom0 > fdt set /chosen/dom0 compatible "xen,linux-zimage" "xen,multiboot-module" "multiboot,module" > fdt set /chosen/dom0 reg <0x0 0x42000000 0x0 0x49F9A8 > > fdt set /chosen xen,dom0-bootargs "console=tty1 root=/dev/mmcblk1p4 rw rootwait clk_ignore_unused --no-log" > bootm 0x51000000 - 0x5ffec000 > > > but when I try to boot FreeBSD I don't get more informations than usual : > > root@devuan-bunsen:/mnt/zroot2/zroot2/OS/Chromebook/domU/freebsd-xen# ./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) > > Are you aware about a new parameter that I can use to have more detailed debug information ? > > On Wed, Dec 20, 2023 at 5:52 AM Warner Losh <imp@bsdimp.com> wrote: >> >> I'd think you'd need the right virtualization loader. I'm not entirely sure the u-boot.bin you've been creating is for a dom-u.. >> If I misunderstood, then the below isn't good advice. Chain booting the u-boot, the first u-boot initializes things so you want >> to start with stage after the SPL. But the different error messages suggest that it's trying to reboot with kexec, which >> isn't supported on armv7 at the moment. >> >> If you could boot in kvm, I think that the following would work.... Though I'm not entirely sure how to >> specify the two .fd files in your setup. The use of qemu is to have an easy env to debug things... I don't >> have a chromebook to try... >> >> My first instinct would be to try qemu on x86 (this is the first step of many to get to your destination). >> >> If you could boot the GENERIC_SD image that we produce using qemu + edk2-arm-code.fd that would >> be a huge first step. This will give you the boot loader, I believe, to boot in the VM that you need better >> than going via the u-boot route. Since you are booting in a virtualized environment, I think it wouldn't >> matter which one :). >> >> So, I did the following to boot the virtualized armv7 FreeBSD environment, following a post on the forums I found and knew to have the right recipe: >> https://forums.freebsd.org/threads/run-boot-freebsd-arm-32bit-image-in-qemu.80765/ >> >> 1. pkg install qemu >> 2. mkdir qemu-armv7-env >> 3. cd qemu-armv7-env >> 4. fetch https://download.freebsd.org/releases/arm/armv7/ISO-IMAGES/14.0/FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD.img.xz >> 5. xz -d -T 0 FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD.img.xz >> 6. dd if=/dev/zero of=pflash0.img bs=1m count=64 >> 7. dd if=/dev/zero of=pflash1.img bs=1m count=64 >> 8. dd if=/usr/local/share/qemu/edk2-arm-code.fd of=pflash0.img conv=notrunc >> 9. dd if=/usr/local/share/qemu/edk2-arm-vars.fd of=pflash1.img conv=notrunc >> 10. cat > start-freebsd-arm.sh >> #!/bin/sh >> qemu-system-arm \ >> -M virt \ >> -m 1024 \ >> -drive file=pflash0.img,format=raw,if=pflash,readonly=on \ >> -drive file=pflash1.img,format=raw,if=pflash \ >> -drive file=$1.img,if=virtio,cache=writethrough \ >> -nographic \ >> -serial mon:stdio >> ^D >> 11. chmod +x start-freebsd-arm.sh >> 12. ./start-freebsd-arm.sh FreeBSD-14.0-RELEASE-arm-armv7-GENERICSD >> >> But I hit a snag with this on qemu 8.1.2 and 8.1.3 with both 13.2 and 14.0: >> >> Starting devd. >> Starting dhclient. >> DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 7 >> Fatal kernel mode data abort: 'Alignment Fault' on read >> trapframe: 0xc4b36a60 >> FSR=00000001, FAR=dd96701a, spsr=20000013 >> r0 =00000000, r1 =00000001, r2 =00000001, r3 =c4b36b4c >> r4 =00000014, r5 =d6618800, r6 =dd96702e, r7 =0000022c >> r8 =00000000, r9 =0000022c, r10=dd96701a, r11=c4b36b90 >> r12=4300ffff, ssp=c4b36af0, slr=c04a9728, pc =c04a9750 >> >> panic: Fatal abort >> cpuid = 0 >> time = 1680843057 >> KDB: stack backtrace: >> #0 0xc035786c at kdb_backtrace+0x48 >> #1 0xc02fdd20 at vpanic+0x140 >> #2 0xc02fdbe0 at vpanic+0 >> #3 0xc06304ac at abort_align+0 >> #4 0xc063052c at abort_align+0x80 >> #5 0xc063017c at abort_handler+0x480 >> #6 0xc060f480 at exception_exit+0 >> #7 0xc04a9750 at udp_input+0x288 >> #8 0xc0473f54 at ip_input+0x1e0 >> #9 0xc04447c0 at netisr_dispatch_src+0xf8 >> #10 0xc043bf2c at ether_demux+0x1a4 >> #11 0xc043d5e4 at ether_nh_input+0x480 >> #12 0xc04447c0 at netisr_dispatch_src+0xf8 >> #13 0xc043c404 at ether_input+0x50 >> #14 0xc01c0838 at vtnet_rx_vq_process+0x880 >> #15 0xc01b70d0 at vtpci_intx_intr+0xac >> #16 0xc02b87f0 at ithread_loop+0x2ec >> #17 0xc02b465c at fork_exit+0xc0 >> Uptime: 19s >> >> I don't know if this is a problem with qemu or FreeBSD's kernel... >> >> Warner >> >> On Tue, Dec 19, 2023 at 3:25 PM Mario Marietto <marietto2008@gmail.com> wrote: >>> >>> I've asked some help on the channel #arm on Reddit and someone replied : >>> >>> https://www.reddit.com/r/arm/comments/18mcir8/i_cant_boot_freebsd_for_arm32_bit_as_domu_with/ >>> >>> Maybe his answer can be useful to understand why it does not work. >>> >>> On Tue, Dec 19, 2023 at 8:33 PM Stefano Stabellini <sstabellini@kernel.org> wrote: >>>> >>>> +Michal >>>> >>>> Hi Mario, >>>> >>>> I am not sure about booting FreeBSD, but I am certain that u-boot works >>>> fine as DomU kernel on ARMv8 (not sure about ARMv7). With this config >>>> file: >>>> >>>> name="test" >>>> kernel="u-boot.bin" >>>> extra = "console=hvc0" >>>> memory=256 >>>> vcpus=1 >>>> disk = [ 'FreeBSD-13.2-RELEASE-armv7.img,raw,xvda' ] >>>> >>>> I don't know for sure if you can boot FreeBSD but you should definitely >>>> be able to see the u-boot command line prompt. The fact that you are >>>> getting this message: >>>> >>>> xc: error: panic: xg_dom_core.c:689: xc_dom_find_loader: no loader found: Invalid kernel >>>> >>>> Means that something is not right in the u-boot configuration or u-boot >>>> build. Michal and Artem (CCed) might know more. From what I recall, >>>> there was nothing special required to get u-boot.bin to boot as domU >>>> kernel, so now I wonder if it is an ARMv7 vs. ARMv8 issue. >>>> >>>> Cheers, >>>> >>>> Stefano >>>> >>>> >>>> On Tue, 19 Dec 2023, Mario Marietto wrote: >>>> > ....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-Extens >>>> > ions), 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 >>>> > >>>> > >>>> > 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 >>>> > >>>> > >>>> > 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. >>>> > >>>> > >>> >>> >>> >>> -- >>> Mario. > > > > -- > Mario. -- Mario.