Re: Values generated by the ViryaOS uboot-script-gen do not work correctly on the Chromebook Snow

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Hi Mario,

It is difficult to know how to change uboot-script-gen if we don't know
why it is currently going wrong.

uboot-script-gen assumes that the memory range specified by
MEMORY_START-MEMORY_END is valid and correct.

So if you specified a valid and correct memory range in your config file
(0x41e00000-0x60000000) why is it failing?

The only thing uboot-script-gen does is choosing aligned addresses
within the MEMORY_START-MEMORY_END range. The addresses are supposed not
to overlap (meaning the initrd will not overwrite part of the kernel
when loaded). If the issue is a bug in uboot-script-gen, such as the
generated addresses overlap or they are not aligned, then we can fix the
alignment or overlap bug. To debug this kind of issues please post:
- the imagebuilder config file
- the generate boot.source script
- the size of all the binaries specified in the imagebuilder config file

On the other hand if 0x41e00000-0x60000000 is not a safe memory range to
use, then you need to specify a different memory range.

Cheers,

Stefano



On Mon, 13 Nov 2023, Mario Marietto wrote:
> Hello.
> 
> I'm trying to find an easier way to the problem that you can read here :
> 
> https://github.com/mobile-virt/u-boot-chromebook-xe303c12/tree/chromebook/xen#starting-a-domu-guest
> 
> where Chuck says :
> 
>  6. Create the u-boot shell commands that will be used to boot Xen and dom0.
> 
> Create a file in /home/user (or any other directory) named bootxen.source 
> with these contents :
> 
> 
> mmc dev 1 && mmc rescan 1
> ext2load mmc 1:3 0x42000000 zImage-6.1.61-stb-xen-cbe+
> ext2load mmc 1:3 0x51000000 xen-4.17-armhf-armmp-0x51004000.ub
> ext2load mmc 1:3 0x5ffec000 exynos5250-snow-6.1.61-stb-xen-cbe+.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=1G 
> dom0_max_vcpus=2 bootscrub=0 vwfi=native"
> 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 0x7D7200 >
> fdt set /chosen xen,dom0-bootargs "console=tty1 root=/dev/mmcblk1p4 rw 
> rootwait clk_ignore_unused"
> bootm 0x51000000 - 0x5ffec000
> 
> The hex value 0x7D7200 is the size of the zImage-6.1.61-stb-xen-cbe+ file, 
> and that value is computed from the uboot-script-gen script
> available from here :
> 
> 
> https://gitlab.com/ViryaOS/imagebuilder
> 
> 
> This is the interesting point :
> 
> 
> Please note that most of the other values in the script generated by the 
> ViryaOS uboot-script-gen do not work correctly with the Chromebook
> Snow, but the script does correctly calculate the size of the dom0 Linux 
> kernel image.
> 
> 
> Some time ago Stefano suggested to put the values below for MEMORY_START and 
> MEMORY_END inside the xen-config file :
> 
> 
> nano xen-config file :
> 
> 
> MEMORY_START="0x41e00000"
> MEMORY_END="0x60000000"
> LOAD_CMD="ext2load mmc 1:3"
> BOOT_CMD="bootm"
> DEVICE_TREE="exynos5250-snow.dtb"
> XEN="xen-4.17-armhf"
> XEN_CMD="console=dtuart dtuart=serial0 dom0_mem=768M dom0_max_vcpus=2 
> bootscrub=0 vwfi=native sched=null"
> DOM0_KERNEL="zImage-6.6.0-xen-dma-mapping"
> DOM0_CMD="console=tty earlycon=xen earlyprintk=xen root=/dev/mmcblk1p4 rw 
> rootwait clk_ignore_unused"
> UBOOT_SOURCE="xen.source"
> 
> 
> bash ./uboot-script-gen -c xen-config -d .
> 
> 
> Image Name:    
> Created:      Thu Nov  2 20:59:24 2023
> Image Type:   ARM Linux Kernel Image (uncompressed)
> Data Size:    884744 Bytes = 864.01 KiB = 0.84 MiB
> Load Address: 42c00000
> Entry Point:  42c00000
> 
> 
> Generated uboot script xen.scr, to be loaded at address 0x42000000:
> ext2load mmc 1:3 0x42000000 xen.scr; source 0x42000000
> 
> 
> and I tried to boot Xen and Linux 6.6 as dom0 :
> 
> SMDK5250 # mmc dev 1
> SMDK5250 # ext2load mmc 1:3 0x42000000 xen.scr; source 0x42000000
> but it did not work : it reboots on the verification screen.
> 
> --
> Mario.
> 
>