![Kirill A. Shutemov](/assets/img/avatar_default.png)
Instruction fault status register, IFSR, was introduced on ARMv6 to provide status information about the last insturction fault. It needed for proper prefetch abort handling. Now we have three prefetch abort model: * legacy - for CPUs before ARMv6. They doesn't provide neither IFSR nor IFAR. We simulate IFSR with section translation fault status for them to generalize code; * ARMv6 - provides IFSR, but not IFAR; * ARMv7 - provides both IFSR and IFAR. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
478 lines
10 KiB
ArmAsm
478 lines
10 KiB
ArmAsm
/*
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* linux/arch/arm/kernel/entry-common.S
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*
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* Copyright (C) 2000 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <asm/unistd.h>
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#include <asm/ftrace.h>
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#include <mach/entry-macro.S>
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#include <asm/unwind.h>
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#include "entry-header.S"
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.align 5
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/*
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* This is the fast syscall return path. We do as little as
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* possible here, and this includes saving r0 back into the SVC
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* stack.
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*/
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ret_fast_syscall:
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UNWIND(.fnstart )
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UNWIND(.cantunwind )
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disable_irq @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne fast_work_pending
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/* perform architecture specific actions before user return */
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arch_ret_to_user r1, lr
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restore_user_regs fast = 1, offset = S_OFF
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UNWIND(.fnend )
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/*
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* Ok, we need to do extra processing, enter the slow path.
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*/
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fast_work_pending:
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str r0, [sp, #S_R0+S_OFF]! @ returned r0
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work_pending:
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tst r1, #_TIF_NEED_RESCHED
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bne work_resched
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tst r1, #_TIF_SIGPENDING|_TIF_NOTIFY_RESUME
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beq no_work_pending
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mov r0, sp @ 'regs'
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mov r2, why @ 'syscall'
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bl do_notify_resume
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b ret_slow_syscall @ Check work again
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work_resched:
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bl schedule
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/*
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* "slow" syscall return path. "why" tells us if this was a real syscall.
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*/
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ENTRY(ret_to_user)
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ret_slow_syscall:
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disable_irq @ disable interrupts
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ldr r1, [tsk, #TI_FLAGS]
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tst r1, #_TIF_WORK_MASK
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bne work_pending
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no_work_pending:
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/* perform architecture specific actions before user return */
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arch_ret_to_user r1, lr
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restore_user_regs fast = 0, offset = 0
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ENDPROC(ret_to_user)
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/*
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* This is how we return from a fork.
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*/
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ENTRY(ret_from_fork)
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bl schedule_tail
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get_thread_info tsk
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ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
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mov why, #1
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tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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beq ret_slow_syscall
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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ENDPROC(ret_from_fork)
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.equ NR_syscalls,0
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#define CALL(x) .equ NR_syscalls,NR_syscalls+1
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#include "calls.S"
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#undef CALL
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#define CALL(x) .long x
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CONFIG_DYNAMIC_FTRACE
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ENTRY(mcount)
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stmdb sp!, {r0-r3, lr}
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mov r0, lr
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sub r0, r0, #MCOUNT_INSN_SIZE
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.globl mcount_call
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mcount_call:
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bl ftrace_stub
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ldr lr, [fp, #-4] @ restore lr
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ldmia sp!, {r0-r3, pc}
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ENTRY(ftrace_caller)
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stmdb sp!, {r0-r3, lr}
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ldr r1, [fp, #-4]
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mov r0, lr
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sub r0, r0, #MCOUNT_INSN_SIZE
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.globl ftrace_call
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ftrace_call:
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bl ftrace_stub
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ldr lr, [fp, #-4] @ restore lr
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ldmia sp!, {r0-r3, pc}
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#else
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ENTRY(__gnu_mcount_nc)
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stmdb sp!, {r0-r3, lr}
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ldr r0, =ftrace_trace_function
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ldr r2, [r0]
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adr r0, ftrace_stub
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cmp r0, r2
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bne gnu_trace
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ldmia sp!, {r0-r3, ip, lr}
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mov pc, ip
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gnu_trace:
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ldr r1, [sp, #20] @ lr of instrumented routine
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mov r0, lr
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sub r0, r0, #MCOUNT_INSN_SIZE
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mov lr, pc
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mov pc, r2
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ldmia sp!, {r0-r3, ip, lr}
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mov pc, ip
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ENTRY(mcount)
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stmdb sp!, {r0-r3, lr}
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ldr r0, =ftrace_trace_function
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ldr r2, [r0]
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adr r0, ftrace_stub
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cmp r0, r2
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bne trace
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ldr lr, [fp, #-4] @ restore lr
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ldmia sp!, {r0-r3, pc}
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trace:
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ldr r1, [fp, #-4] @ lr of instrumented routine
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mov r0, lr
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sub r0, r0, #MCOUNT_INSN_SIZE
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mov lr, pc
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mov pc, r2
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ldr lr, [fp, #-4] @ restore lr
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ldmia sp!, {r0-r3, pc}
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#endif /* CONFIG_DYNAMIC_FTRACE */
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.globl ftrace_stub
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ftrace_stub:
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mov pc, lr
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#endif /* CONFIG_FUNCTION_TRACER */
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/*=============================================================================
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* SWI handler
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*-----------------------------------------------------------------------------
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*/
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/* If we're optimising for StrongARM the resulting code won't
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run on an ARM7 and we can save a couple of instructions.
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--pb */
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#ifdef CONFIG_CPU_ARM710
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#define A710(code...) code
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.Larm710bug:
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ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
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mov r0, r0
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add sp, sp, #S_FRAME_SIZE
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subs pc, lr, #4
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#else
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#define A710(code...)
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#endif
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.align 5
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ENTRY(vector_swi)
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sub sp, sp, #S_FRAME_SIZE
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stmia sp, {r0 - r12} @ Calling r0 - r12
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ARM( add r8, sp, #S_PC )
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ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
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THUMB( mov r8, sp )
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THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr
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mrs r8, spsr @ called from non-FIQ mode, so ok.
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str lr, [sp, #S_PC] @ Save calling PC
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str r8, [sp, #S_PSR] @ Save CPSR
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str r0, [sp, #S_OLD_R0] @ Save OLD_R0
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zero_fp
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/*
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* Get the system call number.
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*/
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#if defined(CONFIG_OABI_COMPAT)
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/*
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* If we have CONFIG_OABI_COMPAT then we need to look at the swi
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* value to determine if it is an EABI or an old ABI call.
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*/
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#ifdef CONFIG_ARM_THUMB
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tst r8, #PSR_T_BIT
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movne r10, #0 @ no thumb OABI emulation
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ldreq r10, [lr, #-4] @ get SWI instruction
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#else
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ldr r10, [lr, #-4] @ get SWI instruction
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A710( and ip, r10, #0x0f000000 @ check for SWI )
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A710( teq ip, #0x0f000000 )
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A710( bne .Larm710bug )
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#endif
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#ifdef CONFIG_CPU_ENDIAN_BE8
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rev r10, r10 @ little endian instruction
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#endif
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#elif defined(CONFIG_AEABI)
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/*
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* Pure EABI user space always put syscall number into scno (r7).
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*/
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A710( ldr ip, [lr, #-4] @ get SWI instruction )
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A710( and ip, ip, #0x0f000000 @ check for SWI )
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A710( teq ip, #0x0f000000 )
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A710( bne .Larm710bug )
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#elif defined(CONFIG_ARM_THUMB)
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/* Legacy ABI only, possibly thumb mode. */
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tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
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addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
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ldreq scno, [lr, #-4]
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#else
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/* Legacy ABI only. */
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ldr scno, [lr, #-4] @ get SWI instruction
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A710( and ip, scno, #0x0f000000 @ check for SWI )
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A710( teq ip, #0x0f000000 )
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A710( bne .Larm710bug )
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#endif
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#ifdef CONFIG_ALIGNMENT_TRAP
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ldr ip, __cr_alignment
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ldr ip, [ip]
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mcr p15, 0, ip, c1, c0 @ update control register
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#endif
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enable_irq
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get_thread_info tsk
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adr tbl, sys_call_table @ load syscall table pointer
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ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
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#if defined(CONFIG_OABI_COMPAT)
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/*
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* If the swi argument is zero, this is an EABI call and we do nothing.
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*
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* If this is an old ABI call, get the syscall number into scno and
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* get the old ABI syscall table address.
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*/
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bics r10, r10, #0xff000000
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eorne scno, r10, #__NR_OABI_SYSCALL_BASE
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ldrne tbl, =sys_oabi_call_table
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#elif !defined(CONFIG_AEABI)
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bic scno, scno, #0xff000000 @ mask off SWI op-code
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eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
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#endif
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stmdb sp!, {r4, r5} @ push fifth and sixth args
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tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
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bne __sys_trace
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cmp scno, #NR_syscalls @ check upper syscall limit
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adr lr, BSYM(ret_fast_syscall) @ return address
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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add r1, sp, #S_OFF
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2: mov why, #0 @ no longer a real syscall
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cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
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eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
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bcs arm_syscall
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b sys_ni_syscall @ not private func
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ENDPROC(vector_swi)
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/*
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* This is the really slow path. We're going to be doing
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* context switches, and waiting for our parent to respond.
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*/
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__sys_trace:
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mov r2, scno
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add r1, sp, #S_OFF
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mov r0, #0 @ trace entry [IP = 0]
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bl syscall_trace
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adr lr, BSYM(__sys_trace_return) @ return address
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mov scno, r0 @ syscall number (possibly new)
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add r1, sp, #S_R0 + S_OFF @ pointer to regs
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cmp scno, #NR_syscalls @ check upper syscall limit
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ldmccia r1, {r0 - r3} @ have to reload r0 - r3
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ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
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b 2b
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__sys_trace_return:
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str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
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mov r2, scno
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mov r1, sp
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mov r0, #1 @ trace exit [IP = 1]
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bl syscall_trace
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b ret_slow_syscall
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.align 5
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#ifdef CONFIG_ALIGNMENT_TRAP
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.type __cr_alignment, #object
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__cr_alignment:
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.word cr_alignment
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#endif
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.ltorg
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/*
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* This is the syscall table declaration for native ABI syscalls.
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* With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
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*/
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#define ABI(native, compat) native
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#ifdef CONFIG_AEABI
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#define OBSOLETE(syscall) sys_ni_syscall
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#else
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#define OBSOLETE(syscall) syscall
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#endif
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.type sys_call_table, #object
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ENTRY(sys_call_table)
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#include "calls.S"
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#undef ABI
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#undef OBSOLETE
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/*============================================================================
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* Special system call wrappers
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*/
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@ r0 = syscall number
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@ r8 = syscall table
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sys_syscall:
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bic scno, r0, #__NR_OABI_SYSCALL_BASE
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cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
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cmpne scno, #NR_syscalls @ check range
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stmloia sp, {r5, r6} @ shuffle args
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movlo r0, r1
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movlo r1, r2
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movlo r2, r3
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movlo r3, r4
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ldrlo pc, [tbl, scno, lsl #2]
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b sys_ni_syscall
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ENDPROC(sys_syscall)
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sys_fork_wrapper:
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add r0, sp, #S_OFF
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b sys_fork
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ENDPROC(sys_fork_wrapper)
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sys_vfork_wrapper:
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add r0, sp, #S_OFF
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b sys_vfork
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ENDPROC(sys_vfork_wrapper)
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sys_execve_wrapper:
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add r3, sp, #S_OFF
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b sys_execve
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ENDPROC(sys_execve_wrapper)
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sys_clone_wrapper:
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add ip, sp, #S_OFF
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str ip, [sp, #4]
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b sys_clone
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ENDPROC(sys_clone_wrapper)
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sys_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_sigreturn
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ENDPROC(sys_sigreturn_wrapper)
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sys_rt_sigreturn_wrapper:
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add r0, sp, #S_OFF
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b sys_rt_sigreturn
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ENDPROC(sys_rt_sigreturn_wrapper)
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sys_sigaltstack_wrapper:
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ldr r2, [sp, #S_OFF + S_SP]
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b do_sigaltstack
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ENDPROC(sys_sigaltstack_wrapper)
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sys_statfs64_wrapper:
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teq r1, #88
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moveq r1, #84
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b sys_statfs64
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ENDPROC(sys_statfs64_wrapper)
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sys_fstatfs64_wrapper:
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teq r1, #88
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moveq r1, #84
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b sys_fstatfs64
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ENDPROC(sys_fstatfs64_wrapper)
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/*
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* Note: off_4k (r5) is always units of 4K. If we can't do the requested
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* offset, we return EINVAL.
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*/
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sys_mmap2:
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#if PAGE_SHIFT > 12
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tst r5, #PGOFF_MASK
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moveq r5, r5, lsr #PAGE_SHIFT - 12
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streq r5, [sp, #4]
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beq do_mmap2
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mov r0, #-EINVAL
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mov pc, lr
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#else
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str r5, [sp, #4]
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b do_mmap2
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#endif
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ENDPROC(sys_mmap2)
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#ifdef CONFIG_OABI_COMPAT
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/*
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* These are syscalls with argument register differences
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*/
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sys_oabi_pread64:
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stmia sp, {r3, r4}
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b sys_pread64
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ENDPROC(sys_oabi_pread64)
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sys_oabi_pwrite64:
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stmia sp, {r3, r4}
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b sys_pwrite64
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ENDPROC(sys_oabi_pwrite64)
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sys_oabi_truncate64:
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mov r3, r2
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mov r2, r1
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b sys_truncate64
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ENDPROC(sys_oabi_truncate64)
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sys_oabi_ftruncate64:
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mov r3, r2
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mov r2, r1
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b sys_ftruncate64
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ENDPROC(sys_oabi_ftruncate64)
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sys_oabi_readahead:
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str r3, [sp]
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mov r3, r2
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mov r2, r1
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b sys_readahead
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ENDPROC(sys_oabi_readahead)
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/*
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* Let's declare a second syscall table for old ABI binaries
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* using the compatibility syscall entries.
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*/
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#define ABI(native, compat) compat
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#define OBSOLETE(syscall) syscall
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.type sys_oabi_call_table, #object
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ENTRY(sys_oabi_call_table)
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#include "calls.S"
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#undef ABI
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#undef OBSOLETE
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#endif
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