# Report about VME-Download-Master-Board(VDMB) ### Discussion about Preboot eXecution Environment(PxE), pros/cons ### Setup * Enable PxE-boot on Asus-X570-Series (Must be in BIOS) * [Manual](https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/PRIME_X570-P/E15829_PRIME_PRO_TUF_GAMING_X570_Series_BIOS_EM_WEB.pdf) Page 29 and 33 #### Pros * Easy to sync multipile system-image between multipile board #### Cons * Since PxE dependent on DHCP server, if you has DHCP-Server in your network domain(192.168.*\<yyy\>*.*xxx*), then you *must* disable one of DHCP server, or binding 2 DHCP server as 1. Because **one network domain can't exist 2 DHCP server** #### Conslution Maybe our *Zybo Solution* seems good (?) ### Error Message `no matching host key type found. Their offer: ssh-rsa` when using `ssh` login VDMB #### Purpose: Enable `SSH` of VDMB, for remote control conveniently Enable just go to `/etc/sshd` to open(append) `port 22` on the VDMB, but encountered error when ```bash [dewei@myPC ~]$ ssh dewei@ip-to-VDMB Unable to negotiate with x.x.x.x port 22: no matching host key type found. Their offer: ssh-rsa ``` Solution: [Refer to here](https://ttys3.dev/post/openssh-8-8-p1-no-matching-host-key-type-found-their-offer-ssh-rsa/) Append following to `~/.ssh/config` ``` bash HostKeyAlgorithms +ssh-rsa PubkeyAcceptedKeyTypes +ssh-rsa ``` ### Show CPU info, for select compile(GCC/Make, 32bits/64bits) tools The CPU is [Intel Core Duo T2500](https://ark.intel.com/content/www/tw/zh/ark/products/27236/intel-core-duo-processor-t2500-2m-cache-2-00-ghz-667-mhz-fsb.html) ``` bash [dewei@NTUSL6 ~]$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 14 model name : Intel(R) Core(TM) Duo CPU T2500 @ 2.00GHz stepping : 12 cpu MHz : 2000.004 cache size : 2048 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon bts aperfmperf pni monitor vmx est tm2 xtpr pdcm dts bogomips : 4000.08 clflush size : 64 cache_alignment : 64 address sizes : 32 bits physical, 32 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 14 model name : Intel(R) Core(TM) Duo CPU T2500 @ 2.00GHz stepping : 12 cpu MHz : 2000.004 cache size : 2048 KB physical id : 0 siblings : 2 core id : 1 cpu cores : 2 apicid : 1 initial apicid : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon bts aperfmperf pni monitor vmx est tm2 xtpr pdcm dts bogomips : 4000.08 clflush size : 64 cache_alignment : 64 address sizes : 32 bits physical, 32 bits virtual power management: ``` ### Compile on Host(your PC), not VDMB Since CPU of VDMB is 32bits, we can compile for it with 64bits-GCC, even on the host(your PC) How to do? [Refer to here](https://stackoverflow.com/questions/3501878/force-gcc-to-compile-32-bit-programs-on-64-bit-platform): add `-m32` flag to `gcc` command ```bash [dewei@myPC ~] gcc -m32 .... ``` ###### tags: `TechReport` `DeWei`