On Mon, 2022-09-19 at 21:47 -0700, mike wrote: /* snip */ > I am having a problem using ldrexb and strexb using inline assembler. The > code is running on a RPi4 on ubuntu 20.04LTS. > > I get an error message "Error: unknown mnemonic `ldrexb' -- `ldrexb > x0,[[sp,8]]'" ldrexb and strexb are Thumb-2 instructions, but RPi4 uses an AArch64 CPU. AArch64 is an extension of the classic ARM instruction set, not an extension of Thumb-2. So you can't use them on AArch64. -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
