TH1520（C910）boot information: CPU1、CPU2、CPU3: failed to come online ; only CPU0 succeed to come online

[ixgbe01]

build LicheePi4A images link：https://github.com/armbian/build.git
build command: sudo ./compile.sh BOARD=licheepi-4a BRANCH=edge RELEASE=jammy BUILD_MINIMAL=no BUILD_DESKTOP=no KERNEL_CONFIGURE=yes COMPRESS_OUTPUTIMAGE=sha,gpg,xz

Linux6.6 kernel link: https://github.com/revyos/th1520-linux-kernel.git
branch: th1520-v6.6.3

opensbi link: https://github.com/riscv-software-src/opensbi.git
branch: master

how to update opensbi binary? you can refer to the following fix:
thead: update linux to 6.6-rc5, update opensbi binary
armbian/build@3098c2f

LicheePi4A TH1520 boot information txt:
licheePi4A_linux6_6_dmesg_official_opensbi.txt

[ 0.090218] smp: Bringing up secondary CPUs ...
[ 1.102092] CPU1: failed to come online
[ 2.129308] CPU2: failed to come online
[ 3.156496] CPU3: failed to come online
[ 3.160519] smp: Brought up 1 node, 1 CPU

However if we use https://github.com/revyos/opensbi.git （branch: th1520-v1.3.1） , LicheePi4A TH1520 boot information is shown as following:
licheePi4A_linux_6_6_dmesg_revyos_opensbi.txt

[ 0.090069] smp: Bringing up secondary CPUs ...
[ 0.118766] cpu1: Ratio of byte access time to unaligned word access is 6.14, unaligned accesses are fast
[ 0.150904] cpu2: Ratio of byte access time to unaligned word access is 6.14, unaligned accesses are fast
[ 0.183032] cpu3: Ratio of byte access time to unaligned word access is 6.14, unaligned accesses are fast
[ 0.193054] smp: Brought up 1 node, 4 CPUs

[RevySR]

armbian kernel config is wrong.

The commit remove fdt_reset_thead
d1e0f7f

https://github.com/T-head-Semi/zero_stage_boot

[pdp7]

@RevySR Do you know how to make use of the changes in zero_stage_boot? I'm not sure about the steps to deploy it onto a board.

[RevySR]

@RevySR Do you know how to make use of the changes in zero_stage_boot? I'm not sure about the steps to deploy it onto a board.

I don't know. Ren Guo knows how to do it

[SiFiveHolland]

The problem is that upstream OpenSBI is missing a HSM driver for this SoC. With or without zero_stage_boot, a proper HSM driver is still needed for CPU power management (hotplug, cpuidle). And once OpenSBI has a real HSM driver, you don't need any assistance from zero_stage_boot for SMP bringup.

[guoren83]

The problem is that upstream OpenSBI is missing a HSM driver for this SoC. With or without zero_stage_boot, a proper HSM driver is still needed for CPU power management (hotplug, cpuidle). And once OpenSBI has a real HSM driver, you don't need any assistance from zero_stage_boot for SMP bringup.

Yes, the th1520 needs an SoC platform HSM driver. The zero_stage_boot is just for the CPU FPGA prototype to replace the reset_sample.

[guoren83]

@RevySR Do you know how to make use of the changes in zero_stage_boot? I'm not sure about the steps to deploy it onto a board.

I don't know. Ren Guo knows how to do it

Before zero_stage_boot gets into the first-stage bootloader, you could revert the removing reset-sample patch first.

[ixgbe01]

armbian kernel config is wrong.

The commit remove fdt_reset_thead d1e0f7f

https://github.com/T-head-Semi/zero_stage_boot

With the help of your advice, CPU1, CPU2, and CPU3 could succeed to come online normally. Thank you so much!