---
# System prepended metadata

title: Report about VME-Download-Master-Board(VDMB)
tags: [TechReport, DeWei]

---

# 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`