lucmann

lucmann

• beqz s0, 1f Expands to beq s0, x0, 1f jump to label 1f if s0 == x0. Note that label 1f means to go to numeric label 1 FORWARD of the given position whose opposite is label 1b meaning to go to numeric label 1 BACKWARD of the given position.
• csrrw t3, CSR_SSCRATCH, a0 Write the value in the csr register CSR_SSCRATCH to t3 register and write the value in a0 back to CSR_SSCRATCH
• jal purgatory Expands to jal x1, purgatory and unconditionally jump to function purgatory() and write PC+4 into x1 (return address) register
• jal t0, .Lbyte_copy_until_aligned_forward Write PC+4 into register t0 and unconditionally jump to label .Lbyte_copy_until_aligned_forward.
• jalr s0 Expands to jalr x1, s0, 0 meaning the target address to jump to is s0 + 0 and write PC+4 into x1 (return address) register

lucmann

• ldp x0, x1, [sp, #0x10] load values from sp+0x10 into x0, x1 respectively

• svc #0x0 trigger SuperVisor Call exception, used to implement syscall, 0x0 is an argument passed into the exception handler (sw intr handler in linux)

lucmann

$ ulimit -a
-t: cpu time (seconds)              unlimited
-f: file size (blocks)              unlimited
-d: data seg size (kbytes)          unlimited
-s: stack size (kbytes)             8192
-c: core file size (blocks)         0
-m: resident set size (kbytes)      unlimited
-u: processes                       31178
-n: file descriptors                1024
-l: locked-in-memory size (kbytes)  65536

lucmann

#!/usr/bin/env bash

set -x

for c in `ls /sys/bus/cpu/devices/cpu[^0]*/online`; do
    echo $1 > $c # 2> /dev/null # delete the first comment sign # in this line if you care about what's wrong.
done

lucmann

$ git remote -v
amd	git@gitlab.freedesktop.org:agd5f/linux.git (fetch)
amd	git@gitlab.freedesktop.org:agd5f/linux.git (push)
drm	git://anongit.freedesktop.org/drm/drm (fetch)
drm	git://anongit.freedesktop.org/drm/drm (push)
drm-misc	git://anongit.freedesktop.org/drm/drm-misc (fetch)
drm-misc	git://anongit.freedesktop.org/drm/drm-misc (push)
mlankhorst	git://people.freedesktop.org/~mlankhorst/linux (fetch)
mlankhorst	git://people.freedesktop.org/~mlankhorst/linux (push)
riscv	git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git (fetch)

lucmann

set from="luc@sietium.com"
set realname="Luc Ma"

# ==================== IMAP =============================
set imap_user = "onion0709@gmail.com"

# git-send-email
# set imap_pass = "xxxx xxxx xxxx xxxx"

lucmann

 git log -L"/^VERSION = /,/^NAME = /:Makefile" --pretty="%h" --no-patch |  
   while read revision; do git show "$revision":Makefile | 
     sed -n -e '/^VERSION = [0-9]/ { N; N; N; N; s/\n/ /g; p }' | 
       sed -e 's/VERSION = //' -e 's/ PATCHLEVEL = /./' -e 's/ SUBLEVEL = /./' -e 's/ EXTRAVERSION = *//' -e 's/NAME/ NAME/'; done

lucmann

 echo "#include <stdio.h>\nint main() { int a = sizeof(struct {}); printf(\"a = %d\\\n\", a); }" | gcc -x c -
 # a = 0
 
  echo "#include <stdio.h>\nint main() { int a = sizeof(struct {}); printf(\"a = %d\\\n\", a); }" | gcc -x c++ -
  # <stdin>:2:36: error: types may not be defined in ‘sizeof’ expressions

lucmann

find -name 'ARB-*.md' -printf '%P\n' | awk '{orig=$0; gsub(/-/, "_"); print "mv", orig, $0}' | bash

# notes
#
# -printf '%P\n' to strip preceding './' from find's output
# orig=$0 to save original file name
# gsub(/-/, "_") to subsititue '-' in the original file name to '_' in the target file name, it happens to '$0' in place
# print "mv", orig, $0 to generate shell command