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
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