com.github.unidbg.arm.backend

Class AbstractBackend

java.lang.Object

com.github.unidbg.arm.backend.AbstractBackend

All Implemented Interfaces:

Backend

Direct Known Subclasses:

UnicornBackend

public abstract class AbstractBackend
extends Object
implements Backend

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractBackend.BreakPointImpl

Constructor Summary

Constructors

Constructor and Description
AbstractBackend()

Method Summary

Modifier and Type	Method and Description
protected static void	checkVectorRegId(int regId, boolean is64Bit)
protected static int	decodeSWI(Emulator<?> emulator, Backend backend, boolean is64Bit)
protected void	enableVFP(boolean is64Bit)
Map<String,Integer>	getCpuFeatures() Returns the CPU feature flags supported by the backend.
long	getMemAllocatedSize() Returns the total virtual memory size allocated via Backend.mem_map(long, long, int).
long	getMemResidentSize() Returns the actual physical memory resident in RAM.
int	getPageSize() Returns the memory page size used by this backend.
void	onInitialize() Called after the backend is constructed to perform any additional initialization, such as mapping exception vector tables (hypervisor) or setting up initial CPU state.
void	registerEmuCountHook(long emu_count) Registers a hook that stops emulation after the specified number of instructions have been executed.
void	removeJitCodeCache(long begin, long end) Invalidates the JIT code cache for the specified address range.
protected void	switchUserMode(boolean is64Bit)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.github.unidbg.arm.backend.Backend

addBreakPoint, context_alloc, context_free, context_restore, context_save, debugger_add, destroy, emu_start, emu_stop, enableVFP, hook_add_new, hook_add_new, hook_add_new, hook_add_new, hook_add_new, hook_add_new, isHypervisor, mem_map, mem_protect, mem_read, mem_unmap, mem_write, reg_read_vector, reg_read, reg_write_vector, reg_write, removeBreakPoint, setFastDebug, setSingleStep, switchUserMode

Constructor Detail

AbstractBackend

public AbstractBackend()

Method Detail

switchUserMode

protected void switchUserMode(boolean is64Bit)

enableVFP

protected void enableVFP(boolean is64Bit)

checkVectorRegId

protected static void checkVectorRegId(int regId,
                                       boolean is64Bit)

decodeSWI

protected static int decodeSWI(Emulator<?> emulator,
                               Backend backend,
                               boolean is64Bit)

onInitialize

public void onInitialize()

Description copied from interface: Backend

Called after the backend is constructed to perform any additional initialization, such as mapping exception vector tables (hypervisor) or setting up initial CPU state.

Specified by:

onInitialize in interface Backend

getPageSize

public int getPageSize()

Description copied from interface: Backend

Returns the memory page size used by this backend. Typically 4KB (dynarmic/kvm) or 16KB (hypervisor on Apple Silicon).

Specified by:

getPageSize in interface Backend

Returns:

page size in bytes

registerEmuCountHook

public void registerEmuCountHook(long emu_count)

Description copied from interface: Backend

Registers a hook that stops emulation after the specified number of instructions have been executed. Used for instruction counting and preemptive scheduling.

Specified by:

registerEmuCountHook in interface Backend

Parameters:

emu_count - maximum number of instructions before the hook fires; must be > 0

removeJitCodeCache

public void removeJitCodeCache(long begin,
                               long end)
                        throws BackendException

Description copied from interface: Backend

Invalidates the JIT code cache for the specified address range. Should be called after modifying code in mapped memory to ensure the backend re-translates the affected region.

Specified by:

removeJitCodeCache in interface Backend

Parameters:

begin - start address of the range (inclusive)

end - end address of the range (exclusive)

Throws:

BackendException - if the operation fails

getCpuFeatures

public Map<String,Integer> getCpuFeatures()

Description copied from interface: Backend

Returns the CPU feature flags supported by the backend.

arm64_features hw.optional.floatingpoint hw.optional.AdvSIMD hw.optional.arm.AdvSIMD hw.optional.arm.FEAT_AES hw.optional.arm.FEAT_PMULL hw.optional.arm.FEAT_SHA1 hw.optional.arm.FEAT_SHA256 hw.optional.armv8_crc32 hw.optional.arm.FEAT_LSE hw.optional.arm.FEAT_FP16 hw.optional.arm.AdvSIMD_HPFPCvt hw.optional.arm.FEAT_RDM hw.optional.arm.FEAT_JSCVT hw.optional.arm.FEAT_FCMA hw.optional.arm.FEAT_LRCPC hw.optional.arm.FEAT_DPB hw.optional.arm.FEAT_SHA3 hw.optional.arm.FEAT_DotProd hw.optional.arm.FEAT_SHA512 hw.optional.arm.FEAT_FHM hw.optional.arm.FEAT_DIT hw.optional.arm.FEAT_LSE2 hw.optional.arm.FEAT_FlagM hw.optional.arm.FEAT_SSBS hw.optional.arm.FEAT_SB hw.optional.arm.FEAT_FlagM2 hw.optional.arm.FEAT_FRINTTS hw.optional.arm.FEAT_I8MM hw.optional.arm.FEAT_BF16 hw.optional.arm.FEAT_BTI

Specified by:

getCpuFeatures in interface Backend

Returns:

a map of feature name to value (1 if supported, 0 otherwise)

getMemAllocatedSize

public long getMemAllocatedSize()

Description copied from interface: Backend

Returns the total virtual memory size allocated via Backend.mem_map(long, long, int).

This is the sum of all mapped pages tracked by the backend's native memory hash table. For unicorn2, this is computed from uc_mem_regions().

Specified by:

getMemAllocatedSize in interface Backend

Returns:

total allocated memory in bytes

getMemResidentSize

public long getMemResidentSize()

Description copied from interface: Backend

Returns the actual physical memory resident in RAM.

On macOS/Linux, this uses mincore() to check which pages are actually backed by physical memory, since mmap(MAP_ANONYMOUS) allocates lazily. Only pages that have been read from or written to will be counted.

On Windows (dynarmic) and unicorn2 (QEMU-based), host memory pointers are not accessible, so this returns the same value as Backend.getMemAllocatedSize().

Specified by:

getMemResidentSize in interface Backend

Returns:

resident memory in bytes