+## NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp\r
+ push rax\r
+ mov rax, qword ptr [rsp][8] # save vector number\r
+ mov ASM_PFX(ExceptionNumber), rax # save vector number\r
+ pop rax\r
+ add rsp, 8 # pop vector number\r
+ mov ASM_PFX(AppRsp), rsp # save stack top\r
+ mov rsp, offset DebugStackBegin # switch to debugger stack\r
+ sub rsp, 8 # leave space for vector number\r
+## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
+## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
+ push r15\r
+ push r14\r
+ push r13\r
+ push r12\r
+ push r11\r
+ push r10\r
+ push r9\r
+ push r8\r
+ push rax\r
+ push rcx\r
+ push rdx\r
+ push rbx\r
+ push rsp\r
+ push rbp\r
+ push rsi\r
+ push rdi\r
+## Save interrupt state rflags register...\r
+ pushfq\r
+ pop rax\r
+ mov qword ptr ASM_PFX(Rflags), rax\r
+## We need to determine if any extra data was pushed by the exception, and if so, save it\r
+## To do this, we check the exception number pushed by the stub, and cache the\r
+## result in a variable since we'll need this again.\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 0\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 10\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 11\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 12\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 13\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 14\r
+ jz ExtraPushOne\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 17\r
+ jz ExtraPushOne\r
+ mov dword ptr ASM_PFX(ExtraPush), 0\r
+ mov dword ptr ASM_PFX(ExceptData), 0\r
+ jmp ExtraPushDone\r
+ExtraPushOne:\r
+ mov dword ptr ASM_PFX(ExtraPush), 1\r
+\r
+## If there's some extra data, save it also, and modify the saved AppRsp to effectively\r
+## pop this value off the application's stack.\r
+ mov rax, ASM_PFX(AppRsp)\r
+ mov rbx, [rax]\r
+ mov ASM_PFX(ExceptData), rbx\r
+ add rax, 8\r
+ mov ASM_PFX(AppRsp), rax\r
+\r
+ExtraPushDone:\r
+\r
+## The "push" above pushed the debug stack rsp. Since what we're actually doing\r
+## is building the context record on the debug stack, we need to save the pushed\r
+## debug RSP, and replace it with the application's last stack entry...\r
+ mov rax, [rsp + 24]\r
+ mov ASM_PFX(DebugRsp), rax\r
+ mov rax, ASM_PFX(AppRsp)\r
+ add rax, 40\r
+ # application stack has ss, rsp, rflags, cs, & rip, so\r
+ # last actual application stack entry is\r
+ # 40 bytes into the application stack.\r
+ mov [rsp + 24], rax\r
+## continue building context record\r
+## UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero\r
+ mov rax, ss\r
+ push rax\r
+ # CS from application is one entry back in application stack\r
+ mov rax, ASM_PFX(AppRsp)\r
+ movzx rax, word ptr [rax + 8]\r
+ push rax\r
+\r
+ mov rax, ds\r
+ push rax\r
+ mov rax, es\r
+ push rax\r
+ mov rax, fs\r
+ push rax\r
+ mov rax, gs\r
+ push rax\r
+## UINT64 Rip;\r
+ # Rip from application is on top of application stack\r
+ mov rax, ASM_PFX(AppRsp)\r
+ push qword ptr [rax]\r
+## UINT64 Gdtr[2], Idtr[2];\r
+ push 0\r
+ push 0\r
+ sidt qword ptr [rsp]\r
+ push 0\r
+ push 0\r
+ sgdt qword ptr [rsp]\r
+\r
+## UINT64 Ldtr, Tr;\r
+ xor rax, rax\r
+ str ax\r
+ push rax\r
+ sldt ax\r
+ push rax\r
+\r
+## UINT64 RFlags;\r
+## Rflags from application is two entries back in application stack\r
+ mov rax, ASM_PFX(AppRsp)\r
+ push qword ptr [rax + 16]\r
+## UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;\r
+## insure FXSAVE/FXRSTOR is enabled in CR4...\r
+## ... while we're at it, make sure DE is also enabled...\r
+ mov rax, cr8\r
+ push rax\r
+ mov rax, cr4\r
+ or rax, 0x208\r
+ mov cr4, rax\r
+ push rax\r
+ mov rax, cr3\r
+ push rax\r
+ mov rax, cr2\r
+ push rax\r
+ push 0\r
+ mov rax, cr0\r
+ push rax\r
+## UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
+ mov rax, dr7\r
+ push rax\r
+## clear Dr7 while executing debugger itself\r
+ xor rax, rax\r
+ mov dr7, rax\r
+\r
+ mov rax, dr6\r
+ push rax\r
+## insure all status bits in dr6 are clear...\r
+ xor rax, rax\r
+ mov dr6, rax\r
+\r
+ mov rax, dr3\r
+ push rax\r
+ mov rax, dr2\r
+ push rax\r
+ mov rax, dr1\r
+ push rax\r
+ mov rax, dr0\r
+ push rax\r
+\r
+## FX_SAVE_STATE_X64 FxSaveState;\r
+ sub rsp, 512\r
+ mov rdi, rsp\r
+ # IMPORTANT!! The debug stack has been carefully constructed to\r
+ # insure that rsp and rdi are 16 byte aligned when we get here.\r
+ # They MUST be. If they are not, a GP fault will occur.\r
+ # FXSTOR_RDI\r
+ .byte 0x0f\r
+ .byte 0xae\r
+ .byte 0x07\r
+\r
+## UINT64 ExceptionData;\r
+ mov rax, ASM_PFX(ExceptData)\r
+ push rax\r
+# call to C code which will in turn call registered handler\r
+# pass in the vector number\r
+ mov rdx, rsp\r
+ mov rcx, ASM_PFX(ExceptionNumber)\r
+ sub rsp, 40\r
+ call ASM_PFX(InterruptDistrubutionHub)\r
+ add rsp, 40\r
+# restore context...\r
+## UINT64 ExceptionData;\r
+ add rsp, 8\r
+## FX_SAVE_STATE_X64 FxSaveState;\r
+ mov rsi, rsp\r
+ # FXRSTOR_RSI\r
+ .byte 0x0f\r
+ .byte 0xae\r
+ .byte 0x0e\r
+ add rsp, 512\r
+;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
+ pop rax\r
+ mov dr0, rax\r
+ pop rax\r
+ mov dr1, rax\r
+ pop rax\r
+ mov dr2, rax\r
+ pop rax\r
+ mov dr3, rax\r
+## skip restore of dr6. We cleared dr6 during the context save.\r
+ add rsp, 8\r
+ pop rax\r
+ mov dr7, rax\r
+## UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;\r
+ pop rax\r
+ mov cr0, rax\r
+ add rsp, 8\r
+ pop rax\r
+ mov cr2, rax\r
+ pop rax\r
+ mov cr3, rax\r
+ pop rax\r
+ mov cr4, rax\r
+ pop rax\r
+ mov cr8, rax\r
+## UINT64 RFlags;\r
+ mov rax, ASM_PFX(AppRsp)\r
+ pop qword ptr [rax + 16]\r
+## UINT64 Ldtr, Tr;\r
+## UINT64 Gdtr[2], Idtr[2];\r
+## Best not let anyone mess with these particular registers...\r
+ add rsp, 48\r
+## UINT64 Rip;\r
+ pop qword ptr [rax]\r
+\r
+## UINT64 Gs, Fs, Es, Ds, Cs, Ss;\r
+## NOTE - modified segment registers could hang the debugger... We\r
+## could attempt to insulate ourselves against this possibility,\r
+## but that poses risks as well.\r
+##\r
+\r
+ pop rax\r
+ # mov gs, rax\r
+ pop rax\r
+ # mov fs, rax\r
+ pop rax\r
+ mov es, rax\r
+ pop rax\r
+ mov ds, rax\r
+ mov rax, ASM_PFX(AppRsp)\r
+ pop qword ptr [rax + 8]\r
+ pop rax\r
+ mov ss, rax\r
+## The next stuff to restore is the general purpose registers that were pushed\r
+## using the "push" instruction.\r
+##\r
+## The value of RSP as stored in the context record is the application RSP\r
+## including the 5 entries on the application stack caused by the exception\r
+## itself. It may have been modified by the debug agent, so we need to\r
+## determine if we need to relocate the application stack.\r
+\r
+ mov rbx, [rsp + 24] # move the potentially modified AppRsp into rbx\r
+ mov rax, ASM_PFX(AppRsp)\r
+ add rax, 40\r
+ cmp rbx, rax\r
+ je NoAppStackMove\r
+\r
+ mov rax, ASM_PFX(AppRsp)\r
+ mov rcx, [rax] # RIP\r
+ mov [rbx], rcx\r
+\r
+ mov rcx, [rax + 8] # CS\r
+ mov [rbx + 8], rcx\r
+\r
+ mov rcx, [rax + 16] # RFLAGS\r
+ mov [rbx + 16], rcx\r
+\r
+ mov rcx, [rax + 24] # RSP\r
+ mov [rbx + 24], rcx\r
+\r
+ mov rcx, [rax + 32] # SS\r
+ mov [rbx + 32], rcx\r
+\r
+ mov rax, rbx # modify the saved AppRsp to the new AppRsp\r
+ mov ASM_PFX(AppRsp), rax\r
+NoAppStackMove:\r
+ mov rax, ASM_PFX(DebugRsp) # restore the DebugRsp on the debug stack\r
+ # so our "pop" will not cause a stack switch\r
+ mov [rsp + 24], rax\r
+\r
+ cmp dword ptr ASM_PFX(ExceptionNumber), 0x068\r
+ jne NoChain\r
+\r
+Chain:\r
+\r
+## Restore rflags so when we chain, the flags will be exactly as if we were never here.\r
+## We gin up the stack to do an iretq so we can get ALL the flags.\r
+ mov rax, ASM_PFX(AppRsp)\r
+ mov rbx, [rax + 40]\r
+ push rbx\r
+ mov rax, ss\r
+ push rax\r
+ mov rax, rsp\r
+ add rax, 16\r
+ push rax\r
+ mov rax, ASM_PFX(AppRsp)\r
+ mov rbx, [rax + 16]\r
+ and rbx, NOT 0x300 # special handling for IF and TF\r
+ push rbx\r
+ mov rax, cs\r
+ push rax\r
+ mov rax, offset PhonyIretq\r
+ push rax\r
+ iretq\r
+PhonyIretq:\r
+\r
+## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
+## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
+ pop rdi\r
+ pop rsi\r
+ pop rbp\r
+ pop rsp\r
+ pop rbx\r
+ pop rdx\r
+ pop rcx\r
+ pop rax\r
+ pop r8\r
+ pop r9\r
+ pop r10\r
+ pop r11\r
+ pop r12\r
+ pop r13\r
+ pop r14\r
+ pop r15\r
+\r
+## Switch back to application stack\r
+ mov rsp, ASM_PFX(AppRsp)\r
+## Jump to original handler\r
+ jmp ASM_PFX(OrigVector)\r
+NoChain:\r
+## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
+## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
+ pop rdi\r
+ pop rsi\r
+ pop rbp\r
+ pop rsp\r
+ pop rbx\r
+ pop rdx\r
+ pop rcx\r
+ pop rax\r
+ pop r8\r
+ pop r9\r
+ pop r10\r
+ pop r11\r
+ pop r12\r
+ pop r13\r
+ pop r14\r
+ pop r15\r
+\r
+## Switch back to application stack\r
+ mov rsp, ASM_PFX(AppRsp)\r
+\r
+## We're outa here...\r
+ iret\r
projects / mirror_edk2.git / commitdiff