QEMU: how to create a 486 VM without fpu - qemu

I'm trying to create a VM of a 486 without FPU, like the 80486SX. I figured this could be accomplished with QEMU. I couldn't find the possibility to directly specify such a cpu (there's only the option -cpu=486). Based on the documentation, I thought it would be possible to remove the FPU by specifying the cpu as follows
qemu-system-i386 -cpu 486,-fpu (...)
But after I installed Debian 5.0 (the last Debian to support the 486), cat/proc tells me that a FPU is indeed considered present (even though it's not in the flags), and gcc will emit floating point instructions for a simple hello-world style program printing doubles, and QEMU will happily execute it.
user#debian-486-nofpu:~/$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 4
model : 8
model name : 486 DX/4
stepping : 0
cache size : 0 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : no
cpuid level : 1
wp : yes
flags : pse
bogomips : 466.94
clflush size : 32
power management:

Related

install openshift on google cloud ( You need to enable virtualization)?

virtualization is enable i've created machine with
gcloud compute instances create openshift-server --enable-nested-virtualization --zone=europe-north1-a --machine-type=e2-standard-4 --image-family=centos-stream-8 --image-project=centos-cloud
i've add libvirt
sudo yum install libvirt
control the cpu virtual active
You need to enable virtualization in BIOS
[n_turri#openshift-server crc-linux-2.9.0-amd64]$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 2
Core(s) per socket: 2
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 79
Model name: Intel(R) Xeon(R) CPU # 2.20GHz
Stepping: 0
CPU MHz: 2200.214
BogoMIPS: 4400.42
Hypervisor vendor: KVM
Virtualization type: full
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 56320K
NUMA node0 CPU(s): 0-3
but when run the setup
You need to enable virtualization in BIOS ??????
n_turri#openshift-server crc-linux-2.9.0-amd64]$ ./crc setup
INFO Using bundle path /home/n_turri/.crc/cache/crc_libvirt_4.11.3_amd64.crcbundle
INFO Checking if running as non-root
INFO Checking if running inside WSL2
INFO Checking if crc-admin-helper executable is cached
INFO Checking for obsolete admin-helper executable
INFO Checking if running on a supported CPU architecture
INFO Checking minimum RAM requirements
INFO Checking if crc executable symlink exists
INFO Checking if Virtualization is enabled
INFO Setting up virtualization
You need to enable virtualization in BIOS

Why does nvidia-smi return "GPU access blocked by the operating system" in WSL2 under Windows 10 21H2 [closed]

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Installing CUDA on WSL2
I've installed Windows 10 21H2 on both my desktop (AMD 5950X system with RTX3080) and my laptop (Dell XPS 9560 with i7-7700HQ and GTX1050) following the instructions on https://docs.nvidia.com/cuda/wsl-user-guide/index.html:
Install CUDA-capable driver in Windows
Update WSL2 kernel in PowerShell: wsl --update
Install CUDA toolkit in Ubuntu 20.04 in WSL2
(Note that you don't install a CUDA driver in WSL2, the instructions explicitly tell that the CUDA driver should not be installed.):
$ wget https://developer.download.nvidia.com/compute/cuda/repos/wsl-ubuntu/x86_64/cuda-wsl-ubuntu.pin
$ sudo mv cuda-wsl-ubuntu.pin /etc/apt/preferences.d/cuda-repository-pin-600
$ wget https://developer.download.nvidia.com/compute/cuda/11.4.0/local_installers/cuda-repo-wsl-ubuntu-11-4-local_11.4.0-1_amd64.deb
$ sudo dpkg -i cuda-repo-wsl-ubuntu-11-4-local_11.4.0-1_amd64.deb
$ sudo apt-key add /var/cuda-repo-wsl-ubuntu-11-4-local/7fa2af80.pub
$ sudo apt-get update
$ sudo apt-get -y install cuda
The Error
On my desktop nvidia-smi and CUDA samples are working fine in WSL2.
But on my laptop running nvidia-smi in WSL2 returns:
$ nvidia-smi
Failed to initialize NVML: GPU access blocked by the operating system
Failed to properly shut down NVML: GPU access blocked by the operating system
I'm aware my laptop has NVIDIA Optimus with both Intel IGP and NVIDIA GTX1050, but CUDA is working fine in Windows. Only not in WSL2.
But I also could not find any information that CUDA is not supposed to work in WSL2 for Optimus systems.
What I've tried
I've tried the following mitigations, but the error remains:
reinstalling the Windows CUDA driver again and rebooting
Making the GTX1050 the preferred GPU in global settings in the NVIDIA control panel
Making the GTX1050 the default physx processor
Following the same steps for a fresh Ubuntu 18.04 in WSL2
The question
Is this a CUDA WSL2 bug? Or does CUDA simply not work with Optimus? Or how can I fix or further debug this?
More details
I've compared running nvidia-smi.exe in Windows powershell between my desktop and laptop, and they both return the same software versions:
PS C:\WINDOWS\system32> nvidia-smi
Wed Nov 17 21:46:50 2021
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 510.06 Driver Version: 510.06 CUDA Version: 11.6 |
|-------------------------------+----------------------+----------------------+
| GPU Name TCC/WDDM | Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 NVIDIA GeForce ... WDDM | 00000000:01:00.0 Off | N/A |
| N/A 44C P8 N/A / N/A | 75MiB / 4096MiB | 1% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| No running processes found |
+-----------------------------------------------------------------------------+
Even more details
The full nvidia-smi.exe -q on my laptop in Windows Powershell returns the following information about my laptop's GPU:
PS C:\WINDOWS\system32> nvidia-smi -q
==============NVSMI LOG==============
Timestamp : Wed Nov 17 21:48:19 2021
Driver Version : 510.06
CUDA Version : 11.6
Attached GPUs : 1
GPU 00000000:01:00.0
Product Name : NVIDIA GeForce GTX 1050
Product Brand : GeForce
Product Architecture : Pascal
Display Mode : Disabled
Display Active : Disabled
Persistence Mode : N/A
MIG Mode
Current : N/A
Pending : N/A
Accounting Mode : Disabled
Accounting Mode Buffer Size : 4000
Driver Model
Current : WDDM
Pending : WDDM
Serial Number : N/A
GPU UUID : GPU-7645072f-7516-5488-316d-6277d101f64e
Minor Number : N/A
VBIOS Version : 86.07.3e.00.1c
MultiGPU Board : No
Board ID : 0x100
GPU Part Number : N/A
Module ID : 0
Inforom Version
Image Version : N/A
OEM Object : N/A
ECC Object : N/A
Power Management Object : N/A
GPU Operation Mode
Current : N/A
Pending : N/A
GSP Firmware Version : N/A
GPU Virtualization Mode
Virtualization Mode : None
Host VGPU Mode : N/A
IBMNPU
Relaxed Ordering Mode : N/A
PCI
Bus : 0x01
Device : 0x00
Domain : 0x0000
Device Id : 0x1C8D10DE
Bus Id : 00000000:01:00.0
Sub System Id : 0x07BE1028
GPU Link Info
PCIe Generation
Max : 3
Current : 3
Link Width
Max : 16x
Current : 16x
Bridge Chip
Type : N/A
Firmware : N/A
Replays Since Reset : 0
Replay Number Rollovers : 0
Tx Throughput : 0 KB/s
Rx Throughput : 0 KB/s
Fan Speed : N/A
Performance State : P8
Clocks Throttle Reasons
Idle : Active
Applications Clocks Setting : Not Active
SW Power Cap : Not Active
HW Slowdown : Not Active
HW Thermal Slowdown : Not Active
HW Power Brake Slowdown : Not Active
Sync Boost : Not Active
SW Thermal Slowdown : Not Active
Display Clock Setting : Not Active
FB Memory Usage
Total : 4096 MiB
Used : 75 MiB
Free : 4021 MiB
BAR1 Memory Usage
Total : 256 MiB
Used : 2 MiB
Free : 254 MiB
Compute Mode : Default
Utilization
Gpu : 0 %
Memory : 0 %
Encoder : 0 %
Decoder : 0 %
Encoder Stats
Active Sessions : 0
Average FPS : 0
Average Latency : 0
FBC Stats
Active Sessions : 0
Average FPS : 0
Average Latency : 0
Ecc Mode
Current : N/A
Pending : N/A
ECC Errors
Volatile
Single Bit
Device Memory : N/A
Register File : N/A
L1 Cache : N/A
L2 Cache : N/A
Texture Memory : N/A
Texture Shared : N/A
CBU : N/A
Total : N/A
Double Bit
Device Memory : N/A
Register File : N/A
L1 Cache : N/A
L2 Cache : N/A
Texture Memory : N/A
Texture Shared : N/A
CBU : N/A
Total : N/A
Aggregate
Single Bit
Device Memory : N/A
Register File : N/A
L1 Cache : N/A
L2 Cache : N/A
Texture Memory : N/A
Texture Shared : N/A
CBU : N/A
Total : N/A
Double Bit
Device Memory : N/A
Register File : N/A
L1 Cache : N/A
L2 Cache : N/A
Texture Memory : N/A
Texture Shared : N/A
CBU : N/A
Total : N/A
Retired Pages
Single Bit ECC : N/A
Double Bit ECC : N/A
Pending Page Blacklist : N/A
Remapped Rows : N/A
Temperature
GPU Current Temp : 40 C
GPU Shutdown Temp : 102 C
GPU Slowdown Temp : 97 C
GPU Max Operating Temp : 78 C
GPU Target Temperature : N/A
Memory Current Temp : N/A
Memory Max Operating Temp : N/A
Power Readings
Power Management : N/A
Power Draw : N/A
Power Limit : N/A
Default Power Limit : N/A
Enforced Power Limit : N/A
Min Power Limit : N/A
Max Power Limit : N/A
Clocks
Graphics : 0 MHz
SM : 0 MHz
Memory : 405 MHz
Video : 0 MHz
Applications Clocks
Graphics : N/A
Memory : N/A
Default Applications Clocks
Graphics : N/A
Memory : N/A
Max Clocks
Graphics : 1911 MHz
SM : 1911 MHz
Memory : 3504 MHz
Video : 1708 MHz
Max Customer Boost Clocks
Graphics : N/A
Clock Policy
Auto Boost : N/A
Auto Boost Default : N/A
Voltage
Graphics : N/A
Processes : None
Turns out that Windows 10 Update Assistant incorrectly reported it upgraded my OS to 21H2 on my laptop.
Checking Windows version by running winver reports that my OS is still 21H1.
Of course CUDA in WSL2 will not work in Windows 10 without 21H2.
After successfully installing 21H2 I can confirm CUDA works with WSL2 even for laptops with Optimus NVIDIA cards.

what's the max resolution that I can achieve using xvfb?

xvfb :1 -screen 0 1600x1200x24
Using this command I can get a 1600x1200 screen. But what keeps me from setting it to xvfb :1 -screen 0 160000x120000x32? Are there any limitations on the screen size that I can use? Is it limited by amount of CPU and RAM that the virtual screen is gonna use?
I couldn't find anything in the documentation that says anything related to this.
xvfb documentation link
I did not find reliable information, i tested with 8k, it works at home (it's bit slow):
xvfb-run -a -s "-screen 0 7680x4320x24" <x11 app>
My config:
CPU: AMD R7 5800H
RAM: 32 GB
GPU: RTX 3070 125W (OC to 140W)

Why boot system, load two versions of u-boot?

I have a gateway device with MT7620a in MIPS architecture. The device has installed OpenWRT. If I connect to device via UART with the goal of flashing new firmware I see something I don't understand, MCU loading two version U-Boot.
U-Boot 1.1.3
Ralink UBoot Version: 4.3.0.0
Here is Log System after start
U-Boot 1.1.3 (Apr 27 2015 - 13:54:38)
Board: Ralink APSoC DRAM: 128 MB
relocate_code Pointer at: 87fb8000
enable ephy clock...done. rf reg 29 = 5
SSC disabled.
spi_wait_nsec: 29
spi device id: 1c 70 18 1c 70 (70181c70)
find flash: EN25QH128A
raspi_read: from:30000 len:1000
*** Warning - bad CRC, using default environment
============================================
Ralink UBoot Version: 4.3.0.0
--------------------------------------------
ASIC 7620_MP (Port5<->None)
DRAM component: 1024 Mbits DDR, width 16
DRAM bus: 16 bit
Total memory: 128 MBytes
Flash component: SPI Flash
Date:Apr 27 2015 Time:13:54:38
Of course I have a few additional questions in this issue:
What is different between these U-Boot ?
Why does my device need two versions U-Boot ?
Whether this u-boots need separate *.bin image or these is together
in one image *.bin ? In my device is only one partition for u-boot image and one partition for variables:
mtd0: 00030000 00010000 "u-boot"
mtd1: 00010000 00010000 "u-boot-env"
As Alexandre Belloni said, there is probably only one version of U-Boot on your device, it just has two different version identifiers.
The reason for this is that manufacturers often need to modify the U-Boot source code in order to get it to operate on their device, or to add features.
On your device, it looks like the version of U-Boot that Ralink pulled from the official U-Boot source code repository is 1.1.3. Ralink's own internal version number that they use for tracking their internal modifications is 4.3.0.0.
There is probably only one u-boot and "Ralink UBoot Version: 4.3.0.0" is an internal u-boot version for Ralink.

Facing issues while launching demo for Oculus SDK 0.6.0.1

I am facing below exception while launching the Oculus SDK 0.6.0.1 demo program.
**Exception Info
Exception report file: C:\Users\Exception Report (2015-06-26 12.41.23).txt
Exception minidump file: C:\Users\Exception Minidump (2015-06-26 12.41.23).mdmp
Time (GMT): 2015/06/26 12:41:23
Time (local): 2015/06/26 18:11:23
Thread name: (not available)
Thread handle: 0x000000d8
Thread sys id: 976 (0x3d0)
Exception instruction address: 0x0ff4f677 (see callstack below)
Exception description: ACCESS_VIOLATION reading address 0x00000000
Exception location: ovr_WaitTillTime (59911)**
below is my app and system Info :
App Info
Process path: C:\Users\Downloads\ovr_sdk_win_0.6.0.0\OculusSDK\Samples\OculusWorldDemo\Release\OculusWorldDemo.exe
App format: 32 bit
App version info not present
System Info
OS name: Windows 7, version: 6.1 build 7601, 32 bit, platform id: 2, service pack: Service Pack 1
Debugger present: no
Processor count: 4
Processor type: x86
Processor level: 6
Processor revision: 10759
Memory load: 87%
Total physical memory: 3240 MiB
Available physical memory: 389 MiB
Total page file memory: 6480 MiB
Available page file memory: 2323 MiB
Total virtual memory: 2047 MiB
Free virtual memory: 1974 MiB
Can someone help me to understand what to do, to fix this issue :(
You didn't include any info about your video hardware & drivers; the first thing I'd try is upgrading them. Also try upgrading to the latest Oculus 0.7.0.1 runtime.