MdePkg: Introduce basic Tdx functions in BaseLib

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / TdCall.nasm

diff --git a/MdePkg/Library/BaseLib/X64/TdCall.nasm b/MdePkg/Library/BaseLib/X64/TdCall.nasm
new file mode 100644 (file)
index 0000000..e8a094b
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X64/TdCall.nasm
@@ -0,0 +1,85 @@
+;------------------------------------------------------------------------------\r
+;*\r
+;* Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>\r
+;* SPDX-License-Identifier: BSD-2-Clause-Patent\r
+;*\r
+;*\r
+;------------------------------------------------------------------------------\r
+\r
+DEFAULT REL\r
+SECTION .text\r
+\r
+%macro tdcall 0\r
+    db 0x66,0x0f,0x01,0xcc\r
+%endmacro\r
+\r
+%macro tdcall_push_regs 0\r
+    push rbp\r
+    mov  rbp, rsp\r
+    push r15\r
+    push r14\r
+    push r13\r
+    push r12\r
+    push rbx\r
+    push rsi\r
+    push rdi\r
+%endmacro\r
+\r
+%macro tdcall_pop_regs 0\r
+    pop rdi\r
+    pop rsi\r
+    pop rbx\r
+    pop r12\r
+    pop r13\r
+    pop r14\r
+    pop r15\r
+    pop rbp\r
+%endmacro\r
+\r
+%define number_of_regs_pushed 8\r
+%define number_of_parameters  4\r
+\r
+;\r
+; Keep these in sync for push_regs/pop_regs, code below\r
+; uses them to find 5th or greater parameters\r
+;\r
+%define first_variable_on_stack_offset \\r
+  ((number_of_regs_pushed * 8) + (number_of_parameters * 8) + 8)\r
+%define second_variable_on_stack_offset \\r
+  ((first_variable_on_stack_offset) + 8)\r
+\r
+;  TdCall (\r
+;    UINT64  Leaf,    // Rcx\r
+;    UINT64  P1,      // Rdx\r
+;    UINT64  P2,      // R8\r
+;    UINT64  P3,      // R9\r
+;    UINT64  Results, // rsp + 0x28\r
+;    )\r
+global ASM_PFX(TdCall)\r
+ASM_PFX(TdCall):\r
+       tdcall_push_regs\r
+\r
+       mov rax, rcx\r
+       mov rcx, rdx\r
+       mov rdx, r8\r
+       mov r8, r9\r
+\r
+       tdcall\r
+\r
+       ; exit if tdcall reports failure.\r
+       test rax, rax\r
+       jnz .exit\r
+\r
+       ; test if caller wanted results\r
+       mov r12, [rsp + first_variable_on_stack_offset ]\r
+       test r12, r12\r
+       jz .exit\r
+       mov [r12 + 0 ], rcx\r
+       mov [r12 + 8 ], rdx\r
+       mov [r12 + 16], r8\r
+       mov [r12 + 24], r9\r
+       mov [r12 + 32], r10\r
+       mov [r12 + 40], r11\r
+.exit:\r
+       tdcall_pop_regs\r
+       ret\r