minix/lib/libc/arch/i386/sys-minix/_senda.S
Ben Gras 2d72cbec41 SYSENTER/SYSCALL support
. add cpufeature detection of both
	. use it for both ipc and kernelcall traps, using a register
	  for call number
	. SYSENTER/SYSCALL does not save any context, therefore userland
	  has to save it
	. to accomodate multiple kernel entry/exit types, the entry
	  type is recorded in the process struct. hitherto all types
	  were interrupt (soft int, exception, hard int); now SYSENTER/SYSCALL
	  is new, with the difference that context is not fully restored
	  from proc struct when running the process again. this can't be
	  done as some information is missing.
	. complication: cases in which the kernel has to fully change
	  process context (i.e. sigreturn). in that case the exit type
	  is changed from SYSENTER/SYSEXIT to soft-int (i.e. iret) and
	  context is fully restored from the proc struct. this does mean
	  the PC and SP must change, as the sysenter/sysexit userland code
	  will otherwise try to restore its own context. this is true in the
	  sigreturn case.
	. override all usage by setting libc_ipc=1
2012-09-24 15:53:43 +02:00

17 lines
398 B
ArmAsm

#include <minix/ipcconst.h>
#include <machine/asm.h>
MSGTAB = 8 /* message table */
TABCOUNT = 12 /* number of entries in message table */
ENTRY(_senda_orig)
push %ebp
movl %esp, %ebp
push %ebx
movl TABCOUNT(%ebp), %eax /* eax = count */
movl MSGTAB(%ebp), %ebx /* ebx = table */
movl $SENDA, %ecx /* _senda(table, count) */
int $IPCVEC /* trap to the kernel */
pop %ebx
pop %ebp
ret