rappel is a Linux-based assembly REPL (read-eval-print loop) supporting Intel syntax. Quite handy to try out various instructions:

rax: 0x0000000000000001	rbx: 0x0000000000000002	rcx: 0x0000000000000000	rdx: 0x0000000000000000
rsi: 0x0000000000000000	rdi: 0x0000000000000000	r8 : 0x0000000000000000	r9 : 0x0000000000000000
r10: 0x0000000000000000	r11: 0x0000000000000000	r12: 0x0000000000000000	r13: 0x0000000000000000
r14: 0x0000000000000000	r15: 0x0000000000000000
rip: 0x0000000000400006	rsp: 0x00007fffd64d8f10	rbp: 0x0000000000000000
flags: 0x0000000000000202 [cf:0, zf:0, of:0, sf:0, pf:0, af:0, df:0]
> add eax,ebx
rax: 0x0000000000000003	rbx: 0x0000000000000002	rcx: 0x0000000000000000	rdx: 0x0000000000000000
rsi: 0x0000000000000000	rdi: 0x0000000000000000	r8 : 0x0000000000000000	r9 : 0x0000000000000000
r10: 0x0000000000000000	r11: 0x0000000000000000	r12: 0x0000000000000000	r13: 0x0000000000000000
r14: 0x0000000000000000	r15: 0x0000000000000000
rip: 0x0000000000400003	rsp: 0x00007fffd64d8f10	rbp: 0x0000000000000000
flags: 0x0000000000000206 [cf:0, zf:0, of:0, sf:0, pf:1, af:0, df:0]

Under the hood, it just runs nasm and observes register values. FP/XMM is supported as well...

posted at: 23:00 | path: /programming | permanent link

Using two 27" monitors now: one Iiyama (3840x2160), one BenQ (1920x1080). The first has way higher DPI. To compensate, I use fractional scaling (175% and 100%). This needs to be enabled for X11, requires Ubuntu 19.04:

gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']"

See here for more details.

posted at: 21:28 | path: /configuration | permanent link