Hi, While reading the vector_swi() routine for arm linux system call, I found that r0-r12 registers are copied to the kernel stack(below is the code). ENTRY(vector_swi) #ifdef CONFIG_CPU_V7M v7m_exception_entry #else sub sp, sp, #S_FRAME_SIZE stmia sp, {r0 - r12} @ Calling r0 - r12 As per my understanding, during system call arm enters into svc mode and jumps to vector_swi()routine and begins execution. The sp register of svc mode(sp_svc)points to kernel stack. r0-r12 registers are copied to the kernel stack. My question is how is the sp (sp_svc) register setup? How does it know the address of kernel stack? Is this kernel stack same as the process's(the process that called system call) kernel stack? Thanks & Regards