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

[Mario Marietto <marietto2008@xxxxxxxxx>]

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.