Add CPU AP hlt-loop code into startup code structure which is located in ACPI NVS range and will be safe during OS booting.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <[email protected]> CC: Michael Kinney <[email protected]> CC: Laszlo Ersek <[email protected]> --- UefiCpuPkg/CpuDxe/ApStartup.c | 12 ++++++++++++ UefiCpuPkg/CpuDxe/CpuMp.h | 8 ++++++++ 2 files changed, 20 insertions(+) diff --git a/UefiCpuPkg/CpuDxe/ApStartup.c b/UefiCpuPkg/CpuDxe/ApStartup.c index 77476ae..7449889 100644 --- a/UefiCpuPkg/CpuDxe/ApStartup.c +++ b/UefiCpuPkg/CpuDxe/ApStartup.c @@ -36,6 +36,12 @@ ENABLE_EXECUTE_DISABLE_CODE mEnableExecuteDisableCodeTemplate = { #endif }; +CPU_AP_RUN_HLT_LOOP_CODE mCpuApRunHltLoopCodeTemplate = { + 0xFA, // cli (Clear Interrupts) + 0xF4, // hlt + {0xEB, 0xFA} // jmp $-2 +}; + /** This .asm code used for translating processor from 16 bit real mode into 64 bit long mode. which help to create the mStartupCodeTemplate value. @@ -317,6 +323,12 @@ PrepareAPStartupCode ( StartupCode->EnableExecuteDisable.Cr3Value = (UINT32) AsmReadCr3 (); #endif + CopyMem ( + (VOID*) &StartupCode->CpuApRunHltLoopCode, + &mCpuApRunHltLoopCodeTemplate, + sizeof (CPU_AP_RUN_HLT_LOOP_CODE) + ); + return EFI_SUCCESS; } diff --git a/UefiCpuPkg/CpuDxe/CpuMp.h b/UefiCpuPkg/CpuDxe/CpuMp.h index feca3be..907e993 100644 --- a/UefiCpuPkg/CpuDxe/CpuMp.h +++ b/UefiCpuPkg/CpuDxe/CpuMp.h @@ -46,6 +46,12 @@ typedef struct { } ENABLE_EXECUTE_DISABLE_CODE; typedef struct { + UINT8 Cli; // cli + UINT8 Hlt; // hlt + UINT8 JmpToHlt[2]; // jmp $-2 +} CPU_AP_RUN_HLT_LOOP_CODE; + +typedef struct { UINT8 JmpToCli[2]; UINT16 GdtLimit; @@ -117,6 +123,8 @@ typedef struct { #endif UINT8 JmpToCpuDxeEntry[2]; + CPU_AP_RUN_HLT_LOOP_CODE CpuApRunHltLoopCode; + } STARTUP_CODE; #pragma pack() -- 1.9.5.msysgit.0 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
