The prototypes of EbcInterpret() and ExecuteEbcImageEntryPoint() are private to the AARCH64 implementation of EbcDxe, so we can shuffle the arguments around a bit and make the assembler thunking glue a lot simpler.
For ExecuteEbcImageEntryPoint(), this involves passing the EntryPoint argument as the third parameter, rather than the first, which allows us to do a tail call. For EbcInterpret(), instead of copying each argument beyond #8 from one native stack frame to the next (before another copy is made into the VM stack), pass a pointer to the argument stack. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> Reviewed-by: Leif Lindholm <leif.lindh...@linaro.org> --- MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S | 59 +++++-------------- MdeModulePkg/Universal/EbcDxe/AArch64/EbcSupport.c | 60 ++++++++------------ 2 files changed, 36 insertions(+), 83 deletions(-) diff --git a/MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S b/MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S index 34794c06a644..b1f09725ecf0 100644 --- a/MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S +++ b/MdeModulePkg/Universal/EbcDxe/AArch64/EbcLowLevel.S @@ -110,50 +110,23 @@ ASM_PFX(EbcLLCALLEXNative): // // This function is called by the thunk code to handle an Native to EBC call // This can handle up to 16 arguments (1-8 on in x0-x7, 9-16 are on the stack) -// x16 contains the Entry point that will be the first argument when +// x16 contains the Entry point that will be the first stacked argument when // EBCInterpret is called. // //**************************************************************************** ASM_PFX(EbcLLEbcInterpret): - stp x29, x30, [sp, #-16]! - - // copy the current arguments 9-16 from old location and add arg 7 to stack - // keeping 16 byte stack alignment - sub sp, sp, #80 - str x7, [sp] - ldr x11, [sp, #96] - str x11, [sp, #8] - ldr x11, [sp, #104] - str x11, [sp, #16] - ldr x11, [sp, #112] - str x11, [sp, #24] - ldr x11, [sp, #120] - str x11, [sp, #32] - ldr x11, [sp, #128] - str x11, [sp, #40] - ldr x11, [sp, #136] - str x11, [sp, #48] - ldr x11, [sp, #144] - str x11, [sp, #56] - ldr x11, [sp, #152] - str x11, [sp, #64] - - // Shift arguments and add entry point and as argument 1 - mov x7, x6 - mov x6, x5 - mov x5, x4 - mov x4, x3 - mov x3, x2 - mov x2, x1 - mov x1, x0 - mov x0, x16 + stp x29, x30, [sp, #-16]! + mov x29, sp - // call C-code - bl ASM_PFX(EbcInterpret) - add sp, sp, #80 + // push the entry point and the address of args #9 - #16 onto the stack + add x17, sp, #16 + stp x16, x17, [sp, #-16]! - ldp x29, x30, [sp], #16 + // call C-code + bl ASM_PFX(EbcInterpret) + add sp, sp, #16 + ldp x29, x30, [sp], #16 ret //**************************************************************************** @@ -165,16 +138,10 @@ ASM_PFX(EbcLLEbcInterpret): // //**************************************************************************** ASM_PFX(EbcLLExecuteEbcImageEntryPoint): - stp x29, x30, [sp, #-16]! - // build new parameter calling convention - mov x2, x1 - mov x1, x0 - mov x0, x16 + mov x2, x16 - // call C-code - bl ASM_PFX(ExecuteEbcImageEntryPoint) - ldp x29, x30, [sp], #16 - ret + // tail call to C code + b ASM_PFX(ExecuteEbcImageEntryPoint) //**************************************************************************** // mEbcInstructionBufferTemplate diff --git a/MdeModulePkg/Universal/EbcDxe/AArch64/EbcSupport.c b/MdeModulePkg/Universal/EbcDxe/AArch64/EbcSupport.c index a5f21f400274..c5cc76d7bdcb 100644 --- a/MdeModulePkg/Universal/EbcDxe/AArch64/EbcSupport.c +++ b/MdeModulePkg/Universal/EbcDxe/AArch64/EbcSupport.c @@ -89,7 +89,6 @@ PushU64 ( This is a thunk function. - @param EntryPoint The entrypoint of EBC code. @param Arg1 The 1st argument. @param Arg2 The 2nd argument. @param Arg3 The 3rd argument. @@ -98,14 +97,8 @@ PushU64 ( @param Arg6 The 6th argument. @param Arg7 The 7th argument. @param Arg8 The 8th argument. - @param Arg9 The 9th argument. - @param Arg10 The 10th argument. - @param Arg11 The 11th argument. - @param Arg12 The 12th argument. - @param Arg13 The 13th argument. - @param Arg14 The 14th argument. - @param Arg15 The 15th argument. - @param Arg16 The 16th argument. + @param EntryPoint The entrypoint of EBC code. + @param Args9_16[] Array containing arguments #9 to #16. @return The value returned by the EBC application we're going to run. @@ -113,23 +106,16 @@ PushU64 ( UINT64 EFIAPI EbcInterpret ( - IN UINTN EntryPoint, - IN UINTN Arg1, - IN UINTN Arg2, - IN UINTN Arg3, - IN UINTN Arg4, - IN UINTN Arg5, - IN UINTN Arg6, - IN UINTN Arg7, - IN UINTN Arg8, - IN UINTN Arg9, - IN UINTN Arg10, - IN UINTN Arg11, - IN UINTN Arg12, - IN UINTN Arg13, - IN UINTN Arg14, - IN UINTN Arg15, - IN UINTN Arg16 + IN UINTN Arg1, + IN UINTN Arg2, + IN UINTN Arg3, + IN UINTN Arg4, + IN UINTN Arg5, + IN UINTN Arg6, + IN UINTN Arg7, + IN UINTN Arg8, + IN UINTN EntryPoint, + IN CONST UINTN Args9_16[] ) { // @@ -193,14 +179,14 @@ EbcInterpret ( // For the worst case, assume there are 4 arguments passed in registers, store // them to VM's stack. // - PushU64 (&VmContext, (UINT64) Arg16); - PushU64 (&VmContext, (UINT64) Arg15); - PushU64 (&VmContext, (UINT64) Arg14); - PushU64 (&VmContext, (UINT64) Arg13); - PushU64 (&VmContext, (UINT64) Arg12); - PushU64 (&VmContext, (UINT64) Arg11); - PushU64 (&VmContext, (UINT64) Arg10); - PushU64 (&VmContext, (UINT64) Arg9); + PushU64 (&VmContext, (UINT64) Args9_16[7]); + PushU64 (&VmContext, (UINT64) Args9_16[6]); + PushU64 (&VmContext, (UINT64) Args9_16[5]); + PushU64 (&VmContext, (UINT64) Args9_16[4]); + PushU64 (&VmContext, (UINT64) Args9_16[3]); + PushU64 (&VmContext, (UINT64) Args9_16[2]); + PushU64 (&VmContext, (UINT64) Args9_16[1]); + PushU64 (&VmContext, (UINT64) Args9_16[0]); PushU64 (&VmContext, (UINT64) Arg8); PushU64 (&VmContext, (UINT64) Arg7); PushU64 (&VmContext, (UINT64) Arg6); @@ -252,10 +238,10 @@ EbcInterpret ( /** Begin executing an EBC image. - @param EntryPoint The entrypoint of EBC code. @param ImageHandle image handle for the EBC application we're executing @param SystemTable standard system table passed into an driver's entry point + @param EntryPoint The entrypoint of EBC code. @return The value returned by the EBC application we're going to run. @@ -263,9 +249,9 @@ EbcInterpret ( UINT64 EFIAPI ExecuteEbcImageEntryPoint ( - IN UINTN EntryPoint, IN EFI_HANDLE ImageHandle, - IN EFI_SYSTEM_TABLE *SystemTable + IN EFI_SYSTEM_TABLE *SystemTable, + IN UINTN EntryPoint ) { // -- 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel