Place and route by Ciro Santilli 40 Updated 2025-07-16
Given a bunch of interlinked standard cell library elements from the logic synthesis step, actually decide where exactly they are going to go on 2D (stacked 2D) integrated circuit surface.
Sample output format of place and route would be GDSII.
Verilog by Ciro Santilli 40 Updated 2025-07-16
Examples under verilog, more details at Verilator.
riscv/timer.S by Ciro Santilli 40 Updated 2025-07-16
Tested on Ubuntu 23.10:
sudo apt install binutils-riscv64-unknown-elf qemu-system-misc gdb-multiarch
cd riscv
make
Then on shell 1:
qemu-system-riscv64 -machine virt -cpu rv64 -smp 1 -s -S -nographic -bios none -kernel timer.elf
and on shell 2:
gdb-multiarch timer.elf -nh -ex "target remote :1234" -ex 'display /i $pc' -ex 'break *mtrap' -ex 'display *0x2004000' -ex 'display *0x200BFF8'
GDB should break infinitel many times on mtrap as interrupts happen.
In v4.2, look under arch/x86/:
  • include/asm/pgtable*
  • include/asm/page*
  • mm/pgtable*
  • mm/page*
There seems to be no structs defined to represent the pages, only macros: include/asm/page_types.h is specially interesting. Excerpt:
#define _PAGE_BIT_PRESENT   0   /* is present */
#define _PAGE_BIT_RW        1   /* writeable */
#define _PAGE_BIT_USER      2   /* userspace addressable */
#define _PAGE_BIT_PWT       3   /* page write through */
arch/x86/include/uapi/asm/processor-flags.h defines CR0, and in particular the PG bit position:
#define X86_CR0_PG_BIT      31 /* Paging */
Erase SSD securely by Ciro Santilli 40 Updated 2025-07-16
You can't just shred individual sSD files because SSD writes only at large granularities, so hardware/drivers have to copy stuff around all the time to compact it. This means that leftover copies are left around everywhere.
What you can do however is to erase the entire thing with vendor support, which most hardware has support for. On hardware encrypted disks, you can even just erase the keys:
TODO does shredding the
pciutils by Ciro Santilli 40 Updated 2025-07-16
Sotware project that provides lspci.
LSF get version by Ciro Santilli 40 Updated 2025-07-16
Most/all commands have the -V option which prints the version, e.g.:
bsub -V

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
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    Screenshot of the "Derivative" topic page
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    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
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    Figure 4.
    Visual Studio Code extension tree navigation
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    Figure 5.
    Web editor
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    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
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    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
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