Eureka

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Glossary

  • PoC: Proof of Concept, 概念验证
  • Chisel: tExtended on Scala
  • GDSII: 版图
  • RTL: Register-Transfer Level, RTL 语言包括 SystemVerilog, Verilog, VHDL等
  • FIRRTL: Chisel 的“翻译器”, Chisel -> Verilog
  • shift left: 把验证和调试放在 tape in 阶段
  • GEM5: C Simulator for GPU
  • PPA: Power, Performance, Area, used in deciding how to optimize semiconductor designs
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LLVM & llvm-project

LLVM 是 Low-Level Virtual Machine 的简写，但事实上它与虚拟机关系不大。我们更熟悉它是一套工具链，包括 clang /'klæŋ/, lld, lldb 等等。接触 LLVM 是因为 Mesa llvmpipe 使用 LLVM, 还有 AMDGPU 和 Radeon 的编译器后端都使用 LLVM IR，所以要编译 Mesa 的 -Dgallium-drivers=llvmpipe,radeonsi 都依赖于 LLVM 的诸多组件, 构建 Linux 内核的 eBPF 程序也依赖 LLVM, 构建 perfetto 也依赖 LLVM。这里主要记录 LLVM 的构建和使用的一些问题。

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Regular Expressions

GNU Extensions

Shorthand Classes

shorthand equivalence
\w [[:alnum:]_]
\W [^[:alnum:]_]
\s [[:space:]]
\S [^[:space:]]

Word Boundaries

shorthand matches
\b position at a word boundary
\B position not at a word boundary
\< position at the start of a word
\> position at the end of a word
\` (backtick) position at the start of subject string
\' (single quote) position at the end of subject string

Perl Compatiable Regular Expression (PCRE)

grep multiline match

  • -P: 使用 Perl 正则表达式扩展
  • -z: 让 grep 把输入的行看成是一个多个行的集合，一个整体
  • .*?: 后面的 ? 表示 .* 按 non-greedy 模式匹配，也就是尽可能少(短)的匹配
  • (?s): 让 . 匹配任意字符，包括 \n (aka. PCRE_DOTALL)

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$SHELL - 日常操作

Linux 下的 Shell 有很多， sh, bash, csh, zsh 等, 这里主要记录一下 bash 和 zsh 的一些不同之处

Parameter Expansion

Use an alternate value

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${var:+WORD}
${var+WORD}

如果 var 没有设置或为空，则这个变量展开为 Nothing (注意：不是空 empty, 是 nothing), 如果被设置了（不包括被设置成空），它展开为 + 后面的 WORD.

如果冒号被省略，则 var 即使被设置为空，它也展开为 + 后面的 WORD

Indirect

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${!var}

如果 var 的值是 MESA_DEBUG, 那么这个形式展开后是变量 MESA_DEBUG 的值，例如 export MESA_DEBUG=1, var=MESA_DEBUG, 则最后的展开结果是 1

Quoted

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${var@Q}

带 @Q 指变量展开后的值被单引号引起来，例如 export ABC=abc, echo "ABC=${ABC@Q}" 的结果是 ABC='abc'

awk - 文本处理

Linux 下的文本处理三剑客: grep, sed, awk, 除了它们其实还有一些小巧的命令，如 tr, cut 也可以帮助我们快速处理和格式化文本。
下面以一个例子为例。

在 Linux 内核源码目录下，搜索 drivers/gpu/drm 下所有的 DRIVER_NAME 定义，并排序后格式化输出

命令如下:

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rg '#define DRIVER_NAME' drivers/gpu/drm --no-heading \
    | tr -s '\t' | tr '\t' ' ' | tr -s ' ' \
    | awk -F':' '{printf("%-52s%-40s\n",$1,$2)}' \
    | sort -k4
  • rg (ripgrep) 比 grep 更快，更强大
  • tr 在不带任何选项时，默认执行替换，例子是中将 tab 替换成 空格, -s 表示 squeeze-repeats, 就是去掉重复的字符，例如多个空格只保留一个
  • awk 天生支持 C-Style printf

输出结果:

  • 格式化之前:
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drivers/gpu/drm/solomon/ssd130x.c:#define DRIVER_NAME	"ssd130x"
drivers/gpu/drm/solomon/ssd130x-i2c.c:#define DRIVER_NAME	"ssd130x-i2c"
drivers/gpu/drm/solomon/ssd130x-spi.c:#define DRIVER_NAME	"ssd130x-spi"
drivers/gpu/drm/exynos/exynos_drm_drv.c:#define DRIVER_NAME	"exynos"
drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c:#define DRIVER_NAME		"imx8qxp-display-pixel-link"
drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c:#define DRIVER_NAME	"imx8qxp-pxl2dpi"
drivers/gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c:#define DRIVER_NAME			"imx8qxp-pixel-combiner"
drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c:#define DRIVER_NAME		"imx8qxp-ldb"
drivers/gpu/drm/bridge/imx/imx8qm-ldb-drv.c:#define DRIVER_NAME			"imx8qm-ldb"
drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c:#define DRIVER_NAME "dw-hdmi-gp-audio"
drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c:#define DRIVER_NAME "dw-hdmi-ahb-audio"
drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c:#define DRIVER_NAME "dw-hdmi-i2s-audio"
drivers/gpu/drm/meson/meson_dw_hdmi.c:#define DRIVER_NAME "meson-dw-hdmi"
drivers/gpu/drm/meson/meson_drv.c:#define DRIVER_NAME "meson"
drivers/gpu/drm/omapdrm/omap_drv.c:#define DRIVER_NAME		MODULE_NAME
drivers/gpu/drm/sprd/sprd_drm.c:#define DRIVER_NAME	"sprd"
drivers/gpu/drm/savage/savage_drv.h:#define DRIVER_NAME	"savage"
drivers/gpu/drm/i810/i810_drv.h:#define DRIVER_NAME		"i810"
drivers/gpu/drm/mediatek/mtk_drm_drv.c:#define DRIVER_NAME "mediatek"
drivers/gpu/drm/mga/mga_drv.h:#define DRIVER_NAME		"mga"
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.h:#define DRIVER_NAME		"amdgpu"
drivers/gpu/drm/vboxvideo/vbox_drv.h:#define DRIVER_NAME         "vboxvideo"
drivers/gpu/drm/vkms/vkms_drv.c:#define DRIVER_NAME	"vkms"
drivers/gpu/drm/via/via_dri1.c:#define DRIVER_NAME		"via"
drivers/gpu/drm/sti/sti_drv.c:#define DRIVER_NAME	"sti"
drivers/gpu/drm/imx/ipuv3/imx-ldb.c:#define DRIVER_NAME "imx-ldb"
drivers/gpu/drm/udl/udl_drv.h:#define DRIVER_NAME		"udl"
drivers/gpu/drm/nouveau/nouveau_drv.h:#define DRIVER_NAME		"nouveau"
drivers/gpu/drm/mgag200/mgag200_drv.h:#define DRIVER_NAME		"mgag200"
drivers/gpu/drm/vgem/vgem_drv.c:#define DRIVER_NAME	"vgem"
drivers/gpu/drm/qxl/qxl_drv.h:#define DRIVER_NAME		"qxl"
drivers/gpu/drm/radeon/radeon_drv.h:#define DRIVER_NAME		"radeon"
drivers/gpu/drm/rockchip/rockchip_drm_drv.c:#define DRIVER_NAME	"rockchip"
drivers/gpu/drm/virtio/virtgpu_drv.h:#define DRIVER_NAME "virtio_gpu"
drivers/gpu/drm/tiny/gm12u320.c:#define DRIVER_NAME		"gm12u320"
drivers/gpu/drm/tiny/simpledrm.c:#define DRIVER_NAME	"simpledrm"
drivers/gpu/drm/tiny/ofdrm.c:#define DRIVER_NAME	"ofdrm"
drivers/gpu/drm/v3d/v3d_drv.c:#define DRIVER_NAME "v3d"
drivers/gpu/drm/gma500/psb_drv.h:#define DRIVER_NAME "gma500"
drivers/gpu/drm/hyperv/hyperv_drm_drv.c:#define DRIVER_NAME "hyperv_drm"
drivers/gpu/drm/sis/sis_drv.h:#define DRIVER_NAME		"sis"
drivers/gpu/drm/tdfx/tdfx_drv.h:#define DRIVER_NAME		"tdfx"
drivers/gpu/drm/i915/i915_driver.h:#define DRIVER_NAME		"i915"
drivers/gpu/drm/r128/r128_drv.h:#define DRIVER_NAME		"r128"
drivers/gpu/drm/tiny/cirrus.c:#define DRIVER_NAME "cirrus"
drivers/gpu/drm/tegra/drm.c:#define DRIVER_NAME "tegra"
drivers/gpu/drm/ast/ast_drv.h:#define DRIVER_NAME		"ast"
drivers/gpu/drm/vc4/vc4_drv.c:#define DRIVER_NAME "vc4"
  • 格式化之后:
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drivers/gpu/drm/amd/amdgpu/amdgpu_drv.h             #define DRIVER_NAME "amdgpu"            
drivers/gpu/drm/ast/ast_drv.h                       #define DRIVER_NAME "ast"               
drivers/gpu/drm/tiny/cirrus.c                       #define DRIVER_NAME "cirrus"            
drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c #define DRIVER_NAME "dw-hdmi-ahb-audio" 
drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c  #define DRIVER_NAME "dw-hdmi-gp-audio"  
drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c #define DRIVER_NAME "dw-hdmi-i2s-audio" 
drivers/gpu/drm/exynos/exynos_drm_drv.c             #define DRIVER_NAME "exynos"            
drivers/gpu/drm/tiny/gm12u320.c                     #define DRIVER_NAME "gm12u320"          
drivers/gpu/drm/gma500/psb_drv.h                    #define DRIVER_NAME "gma500"            
drivers/gpu/drm/hyperv/hyperv_drm_drv.c             #define DRIVER_NAME "hyperv_drm"        
drivers/gpu/drm/i810/i810_drv.h                     #define DRIVER_NAME "i810"              
drivers/gpu/drm/i915/i915_driver.h                  #define DRIVER_NAME "i915"              
drivers/gpu/drm/imx/ipuv3/imx-ldb.c                 #define DRIVER_NAME "imx-ldb"           
drivers/gpu/drm/bridge/imx/imx8qm-ldb-drv.c         #define DRIVER_NAME "imx8qm-ldb"        
drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c     #define DRIVER_NAME "imx8qxp-display-pixel-link"
drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c        #define DRIVER_NAME "imx8qxp-ldb"       
drivers/gpu/drm/bridge/imx/imx8qxp-pixel-combiner.c #define DRIVER_NAME "imx8qxp-pixel-combiner"
drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c        #define DRIVER_NAME "imx8qxp-pxl2dpi"   
drivers/gpu/drm/mediatek/mtk_drm_drv.c              #define DRIVER_NAME "mediatek"          
drivers/gpu/drm/meson/meson_drv.c                   #define DRIVER_NAME "meson"             
drivers/gpu/drm/meson/meson_dw_hdmi.c               #define DRIVER_NAME "meson-dw-hdmi"     
drivers/gpu/drm/mga/mga_drv.h                       #define DRIVER_NAME "mga"               
drivers/gpu/drm/mgag200/mgag200_drv.h               #define DRIVER_NAME "mgag200"           
drivers/gpu/drm/nouveau/nouveau_drv.h               #define DRIVER_NAME "nouveau"           
drivers/gpu/drm/tiny/ofdrm.c                        #define DRIVER_NAME "ofdrm"             
drivers/gpu/drm/qxl/qxl_drv.h                       #define DRIVER_NAME "qxl"               
drivers/gpu/drm/r128/r128_drv.h                     #define DRIVER_NAME "r128"              
drivers/gpu/drm/radeon/radeon_drv.h                 #define DRIVER_NAME "radeon"            
drivers/gpu/drm/rockchip/rockchip_drm_drv.c         #define DRIVER_NAME "rockchip"          
drivers/gpu/drm/savage/savage_drv.h                 #define DRIVER_NAME "savage"            
drivers/gpu/drm/tiny/simpledrm.c                    #define DRIVER_NAME "simpledrm"         
drivers/gpu/drm/sis/sis_drv.h                       #define DRIVER_NAME "sis"               
drivers/gpu/drm/sprd/sprd_drm.c                     #define DRIVER_NAME "sprd"              
drivers/gpu/drm/solomon/ssd130x.c                   #define DRIVER_NAME "ssd130x"           
drivers/gpu/drm/solomon/ssd130x-i2c.c               #define DRIVER_NAME "ssd130x-i2c"       
drivers/gpu/drm/solomon/ssd130x-spi.c               #define DRIVER_NAME "ssd130x-spi"       
drivers/gpu/drm/sti/sti_drv.c                       #define DRIVER_NAME "sti"               
drivers/gpu/drm/tdfx/tdfx_drv.h                     #define DRIVER_NAME "tdfx"              
drivers/gpu/drm/tegra/drm.c                         #define DRIVER_NAME "tegra"             
drivers/gpu/drm/udl/udl_drv.h                       #define DRIVER_NAME "udl"               
drivers/gpu/drm/v3d/v3d_drv.c                       #define DRIVER_NAME "v3d"               
drivers/gpu/drm/vboxvideo/vbox_drv.h                #define DRIVER_NAME "vboxvideo"         
drivers/gpu/drm/vc4/vc4_drv.c                       #define DRIVER_NAME "vc4"               
drivers/gpu/drm/vgem/vgem_drv.c                     #define DRIVER_NAME "vgem"              
drivers/gpu/drm/via/via_dri1.c                      #define DRIVER_NAME "via"               
drivers/gpu/drm/virtio/virtgpu_drv.h                #define DRIVER_NAME "virtio_gpu"        
drivers/gpu/drm/vkms/vkms_drv.c                     #define DRIVER_NAME "vkms"              
drivers/gpu/drm/omapdrm/omap_drv.c                  #define DRIVER_NAME MODULE_NAME

crontab - 定时任务

crontab -e (添加定时任务)， 不光可以添加周期性的定时任务，也可以添加开机时一次性任务

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@reboot /home/luc/mystart.sh

crontab 是每用户的， 就是说当前用户设定的任务，只有当前用户的权限，所以如果有些情况下任务执行需要 root 权限，就需要切换到 root 用户后 crontab -e

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Markdown to PDF

Highly recommended 3 utilities:

  • pandoc 标记语言转换领域的"瑞士军刀"
  • TexLive 开发最为活跃的 TeX 发行版之一
  • eisvogel 简洁的 pandoc LaTex 模板

eisvogel 要求一个完整的 TexLive 的安装环境，但通常像 CentOS 这样的 Linux 发行版自带的 TexLive 并不完整。

How to Install texlive.iso

Quick Install

将 TexLive 的镜像下载并挂载后，通过顶层目录下的 install-tl 这个 Perl 脚本程序安装，整个安装过程要注意以下几点。

mount ISO image

假设在 Linux 下，通过 root 用户或 sudo 挂载镜像文件

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mkdir -p /mnt/iso
mount /path/to/texlive.iso /mnt/iso -o loop

run installer

TexLive 的 installer 是一个 perl script, 提供 text mode 和 GUI mode 两种安装模式.

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======================> TeX Live installation procedure <=====================

======>   Letters/digits in <angle brackets> indicate   <=======
======>   menu items for actions or customizations      <=======
= help>   https://tug.org/texlive/doc/install-tl.html   <=======

 Detected platform: GNU/Linux on x86_64

 <B> set binary platforms: 1 out of 6

 <S> set installation scheme: scheme-full

 <C> set installation collections:
     40 collections out of 41, disk space required: 7262 MB (free: 168365 MB)

 <D> set directories:
   TEXDIR (the main TeX directory):
     !! default location: /usr/local/texlive/2022
     !! is not writable or not allowed, please select a different one!
   TEXMFLOCAL (directory for site-wide local files):
     /usr/local/texlive/texmf-local
   TEXMFSYSVAR (directory for variable and automatically generated data):
     /usr/local/texlive/2022/texmf-var
   TEXMFSYSCONFIG (directory for local config):
     /usr/local/texlive/2022/texmf-config
   TEXMFVAR (personal directory for variable and automatically generated data):
     ~/.texlive2022/texmf-var
   TEXMFCONFIG (personal directory for local config):
     ~/.texlive2022/texmf-config
   TEXMFHOME (directory for user-specific files):
     ~/texmf

 <O> options:
   [ ] use letter size instead of A4 by default
   [X] allow execution of restricted list of programs via \write18
   [X] create all format files
   [X] install macro/font doc tree
   [X] install macro/font source tree
   [ ] create symlinks to standard directories
   [X] after install, set CTAN as source for package updates

 <V> set up for portable installation

Actions:
 <I> start installation to hard disk
 <P> save installation profile to 'texlive.profile' and exit
 <Q> quit

Enter command:
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Options customization:

 <P> use letter size instead of A4 by default: [ ]
 <E> execution of restricted list of programs: [X]
 <F> create all format files:                  [X]
 <D> install font/macro doc tree:              [X]
 <S> install font/macro source tree:           [X]
 <L> create symlinks in standard directories:  [X]
            binaries to: /usr/bin
            manpages to: /usr/man
                info to: /usr/info
 <Y> after install, set CTAN as source for package updates:
                                               [X]

最好勾选此选项，避免使用 TexLive 时各种 Not Found, 原因是 TexLive 默认安装路径并不是标准 Linux 可执行程序的路径(如 /usr/bin), 而是 /usr/local/texlive, 如在 x86_64 安装 texlive2022.iso, 则可执行程序被安装在 /usr/local/texlive/2022/bin/x86_64-linux. 假如不想因为该路径没有在 PATH 里，最好就是在安装时直接在 /usr/bin 下创建相应符号链接。

texlive-full

在使用 xelatex, pdflatex 等 latex 程序时，可以常常遇到类似

! LaTeX Error: File 'fontawesome.sty' not found

xxx.sty 这样的报错，一般是缺少某个 texlive 包，但 texlive 的包太多了，如果懒得一个一个安装，可以

sudo apt install texlive-full

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find 命令

find 命令用来在目录树里查找文件。本文主要介绍 GNU find. 它从每个 starting-point 开始递归搜索，通过求值 expression 的真值来确定输出结果。

find 的命令行组成

example-of-find

  • Options
  • Starting-point
  • Expression
    • Tests
    • Actions
    • Global options
    • Position options
    • Operators

Examples

  • 只在当前目录搜索（不递归）不以 f 或 g 或 h 开头的目录

    • find . -maxdepth 1 -name '[^fgh]*' -type d
      • -type d: 找目录
      • -type f: 找文件(不包括 symbolic link)
      • -type l: 找符号链接文件

  • 排除/proc 和 /tmp 这两个目录

    • find / -path /proc -prune -o -path /tmp -prune -o -name "README.md"
      • -prune 告诉 find 跳过前面的目录，也可以用 \( -o \) 将多个 -path 合并，只保留一个 -prune

  • 只在当前目录查找除了指定及隐藏目录以外的所有目录，打印并删除

    • find -maxdepth 1 \( -path ./gh -o -path ./aaa -o -path ./mesa-install -o -path ./1.3.290.0 -o -path ./1.3.280.1 \) -prune -o -type d ! -name ".*" -print -exec rm -rf {} \;
      • 注意匹配隐藏目录时用 .*, . 在 shell 里不是通配符
      • -print： 不让 ./gh, ./aaa 这些目录出现在 find 命令的输出结果中

  • 查找 ~/gh 目录下只有文件属主(u)有执行权限(x)的文件 (精确匹配文件的 permission bits)

    • find ~/gh -perm u=x -type f

  • 查找 ~/gh 目录下文件属主(u)有执行权限(x) 的文件（组用户(g)或其它用户(o)可能有或没有执行权限）

    • find ~/gh -perm -u=x -type f
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