AMD KB reset 發兩次 (AMI)

SBSECInit.asm

IF MKF_SB900_RESET_WORKAROUND
;; Warm reset work around ( Do cold reset) end
;SB900 CF9 Reset workaround
    cmp   BYTE PTR DS:[0Ffff0h], 0EAh ; Is it warm reset ?
    jne NotWarmReset

    mov dx,0cf9h
    mov ax,6   ;hw reset
    out dx,ax

    mov dx,80h
    out dx,al

    jmp $
NotWarmReset:


As I check the KBC reset in Godvari platform , I can see 2 reset in the wave form ,
after trace , it seems to be the workaround from old chipset ...
a warm reset will issue a cold reset  right after it ...

AMI Debug code

================================================
StatusCodeMap.c , StatusCodeMapPei.c
================================================
//**********************************************************************
// Checkpoints map
//**********************************************************************
//1        - 0xF : SEC execution
//0x10 - 0x2F: PEI CAR execution
//0x30 - 0x4F: PEI execution after memory detection
//0x50 - 0x5F: PEI errors
//0x60 - 0xCF: DXE execution
//0xD0 - 0xDF: DXE errors
//0xE0 - 0xE8: S3 Resume
//0xE9 - 0xEF: S3 Resume errors
//0xF0 - 0xF8: Recovery
//0xF9 - 0xFF: Recovery errors

================================================
PEI
================================================
STATUS_CODE_TO_BYTE_MAP ProgressCheckpointMap[] =
{

//Regular boot
    { PEI_CORE_STARTED, 0x10 },
    { PEI_CAR_CPU_INIT, 0x11 },
    // reserved for CPU 0x12 - 0x14
    { PEI_CAR_NB_INIT, 0x15 },
    // reserved for NB 0x16 - 0x18
    { PEI_CAR_SB_INIT, 0x19 },
    // reserved for SB 0x1A - 0x1C
    // reserved for OEM use: 0x1D - 0x2A
    { PEI_MEMORY_SPD_READ, 0x2B },
    { PEI_MEMORY_PRESENCE_DETECT, 0x2C },
    { PEI_MEMORY_TIMING, 0x2D},
    { PEI_MEMORY_CONFIGURING, 0x2E },
    { PEI_MEMORY_INIT, 0x2F },
    // reserved for AML use: 0x30
    { PEI_MEMORY_INSTALLED, 0x31 },
    { PEI_CPU_INIT,  0x32 },
    { PEI_CPU_CACHE_INIT, 0x33 },
    { PEI_CPU_AP_INIT, 0x34 },
    { PEI_CPU_BSP_SELECT, 0x35 },
    { PEI_CPU_SMM_INIT, 0x36 },
    { PEI_MEM_NB_INIT, 0x37 },
    // reserved for NB 0x38 - 0x3A
    { PEI_MEM_SB_INIT, 0x3B },
    // reserved for SB 0x3C - 0x3E
    // reserved for OEM use: 0x3F - 0x4E
    { PEI_DXE_IPL_STARTED, 0x4F },
    { DXE_CORE_STARTED, 0x60 },
//Recovery
    { PEI_RECOVERY_AUTO, 0xF0 },
    { PEI_RECOVERY_USER, 0xF1 },
    { PEI_RECOVERY_STARTED, 0xF2 },
    { PEI_RECOVERY_CAPSULE_FOUND, 0xF3 },
    { PEI_RECOVERY_CAPSULE_LOADED, 0xF4 },
//S3
    { PEI_S3_STARTED, 0xE0 },
    { PEI_S3_BOOT_SCRIPT, 0xE1 },
    { PEI_S3_VIDEO_REPOST, 0xE2 },
    { PEI_S3_OS_WAKE, 0xE3 },

    {0,0}
};

STATUS_CODE_TO_BYTE_MAP ErrorCheckpointMap[] =
{

//Errors
//Regular boot
    { PEI_MEMORY_INVALID_TYPE, 0x50 },
    { PEI_MEMORY_INVALID_SPEED, 0x50 },
    { PEI_MEMORY_SPD_FAIL, 0x51 },
    { PEI_MEMORY_INVALID_SIZE, 0x52 },
    { PEI_MEMORY_MISMATCH, 0x52 },
    { PEI_MEMORY_NOT_DETECTED, 0x53 },
    { PEI_MEMORY_NONE_USEFUL, 0x53 },
    { PEI_MEMORY_ERROR, 0x54 },
    { PEI_MEMORY_NOT_INSTALLED, 0x55 },
    { PEI_CPU_INVALID_TYPE, 0x56 },
    { PEI_CPU_INVALID_SPEED, 0x56 },
    { PEI_CPU_MISMATCH, 0x57 },
    { PEI_CPU_SELF_TEST_FAILED, 0x58 },
    { PEI_CPU_CACHE_ERROR, 0x58 },
    { PEI_CPU_MICROCODE_UPDATE_FAILED, 0x59 },
    { PEI_CPU_NO_MICROCODE, 0x59 },
    { PEI_CPU_INTERNAL_ERROR, 0x5A },
    { PEI_CPU_ERROR, 0x5A },
    { PEI_RESET_NOT_AVAILABLE,0x5B },
    //reserved for AMI use: 0x5C - 0x5F
//Recovery
    { PEI_RECOVERY_PPI_NOT_FOUND, 0xF8 },
    { PEI_RECOVERY_NO_CAPSULE, 0xF9 },
    { PEI_RECOVERY_INVALID_CAPSULE, 0xFA },
    //reserved for AMI use: 0xFB - 0xFF
//S3 Resume
    { PEI_MEMORY_S3_RESUME_FAILED, 0xE8 },
    { PEI_S3_RESUME_PPI_NOT_FOUND, 0xE9 },
    { PEI_S3_BOOT_SCRIPT_ERROR, 0xEA },
    { PEI_S3_OS_WAKE_ERROR, 0xEB },
    //reserved for AMI use: 0xEC - 0xEF

    {0,0}
};

//**********************************************************************
// Beep codes map
//**********************************************************************
STATUS_CODE_TO_BYTE_MAP ProgressBeepMap[] =
{

//Recovery
    { PEI_RECOVERY_STARTED, 2 },

    {0,0}
};

STATUS_CODE_TO_BYTE_MAP ErrorBeepMap[] =
{

//Errors
//Regular boot
    { PEI_MEMORY_NOT_INSTALLED, 1 },
    { PEI_MEMORY_INSTALLED_TWICE, 1 },
    { PEI_DXEIPL_NOT_FOUND, 3 },
    { PEI_DXE_CORE_NOT_FOUND, 3 },
    { PEI_RESET_NOT_AVAILABLE, 7 },
//Recovery
    { PEI_RECOVERY_FAILED, 4 },
//S3 Resume
    { PEI_S3_RESUME_FAILED, 4 },

    {0,0}
};

================================================
DXE
================================================

STATUS_CODE_TO_BYTE_MAP ProgressCheckpointMap[] =
{
    { DXE_CORE_STARTED, 0x60 },
    { DXE_NVRAM_INIT, 0x61 },
    { DXE_SBRUN_INIT, 0x62 },
    { DXE_CPU_INIT, 0x63 },
    //reserved for CPU 0x64 - 0x67
    { DXE_NB_HB_INIT, 0x68 },
    { DXE_NB_INIT, 0x69 },
    { DXE_NB_SMM_INIT, 0x6A },
    //reserved for NB 0x6B - 0x6F
    { DXE_SB_INIT, 0x70 },
    { DXE_SB_SMM_INIT, 0x71 },
    { DXE_SB_DEVICES_INIT, 0x72 },
    //reserved for SB 0x73 - 0x77
    { DXE_ACPI_INIT, 0x78 },
    { DXE_CSM_INIT, 0x79 },
    //reserved for AMI use: 0x7A - 0x7F
    //reserved for OEM use: 0x80 - 0x8F
    { DXE_BDS_STARTED, 0x90 },
    { DXE_BDS_CONNECT_DRIVERS, 0x91 },
    { DXE_PCI_BUS_BEGIN, 0x92 },
    { DXE_PCI_BUS_HPC_INIT, 0x93 },
    { DXE_PCI_BUS_ENUM, 0x94 },
    { DXE_PCI_BUS_REQUEST_RESOURCES, 0x95 },
    { DXE_PCI_BUS_ASSIGN_RESOURCES, 0x96 },
    { DXE_CON_OUT_CONNECT, 0x97 },
    { DXE_CON_IN_CONNECT, 0x98 },
    { DXE_SIO_INIT, 0x99 },
    { DXE_USB_BEGIN, 0x9A },
    { DXE_USB_RESET, 0x9B },
    { DXE_USB_DETECT, 0x9C },
    { DXE_USB_ENABLE, 0x9D },
    //reserved for AMI use: 0x9E - 0x9F
    { DXE_IDE_BEGIN, 0xA0 },
    { DXE_IDE_RESET, 0xA1 },
    { DXE_IDE_DETECT, 0xA2 },
    { DXE_IDE_ENABLE, 0xA3 },
    { DXE_SCSI_BEGIN, 0xA4 },
    { DXE_SCSI_RESET, 0xA5 },
    { DXE_SCSI_DETECT, 0xA6 },
    { DXE_SCSI_ENABLE, 0xA7 },
    { DXE_SETUP_VERIFYING_PASSWORD, 0xA8 },
    { DXE_SETUP_START, 0xA9 },
    //reserved for AML use: 0xAA
    { DXE_SETUP_INPUT_WAIT, 0xAB },
    //reserved for AML use: 0xAC
    { DXE_READY_TO_BOOT, 0xAD },
    { DXE_LEGACY_BOOT, 0xAE },
    { DXE_EXIT_BOOT_SERVICES, 0xAF },
    { RT_SET_VIRTUAL_ADDRESS_MAP_BEGIN, 0xB0 },
    { RT_SET_VIRTUAL_ADDRESS_MAP_END, 0xB1 },
    { DXE_LEGACY_OPROM_INIT, 0xB2 },
    { DXE_RESET_SYSTEM, 0xB3 },
    { DXE_USB_HOTPLUG, 0xB4 },
    { DXE_PCI_BUS_HOTPLUG, 0xB5 },
    { DXE_NVRAM_CLEANUP, 0xB6 },
    { DXE_CONFIGURATION_RESET, 0xB7 },
    //reserved for AMI use: 0xB8 - 0xBF
    //reserved for OEM use: 0xC0 - 0xCF

    {0,0}
};

STATUS_CODE_TO_BYTE_MAP ErrorCheckpointMap[] =
{
    { DXE_CPU_ERROR, 0xD0 },
    { DXE_NB_ERROR, 0xD1 },
    { DXE_SB_ERROR, 0xD2 },
    { DXE_ARCH_PROTOCOL_NOT_AVAILABLE, 0xD3 },
    { DXE_PCI_BUS_OUT_OF_RESOURCES, 0xD4 },
    { DXE_LEGACY_OPROM_NO_SPACE, 0xD5 },
    { DXE_NO_CON_OUT, 0xD6 },
    { DXE_NO_CON_IN, 0xD7 },
    { DXE_INVALID_PASSWORD, 0xD8 },
    { DXE_BOOT_OPTION_LOAD_ERROR, 0xD9 },
    { DXE_BOOT_OPTION_FAILED, 0xDA },
    { DXE_FLASH_UPDATE_FAILED, 0xDB },
    { DXE_RESET_NOT_AVAILABLE, 0xDC },
    //reserved for AMI use: 0xDE - 0xDF

    {0,0}
};

//**********************************************************************
// Beep codes map
//**********************************************************************
STATUS_CODE_TO_BYTE_MAP ProgressBeepMap[] =
{
    {0,0}
};

STATUS_CODE_TO_BYTE_MAP ErrorBeepMap[] =
{
    { DXE_ARCH_PROTOCOL_NOT_AVAILABLE, 4 },
    { DXE_NO_CON_OUT, 5 },
    { DXE_NO_CON_IN, 5 },
    { DXE_INVALID_PASSWORD, 1 },
    { DXE_FLASH_UPDATE_FAILED, 6 },
    { DXE_RESET_NOT_AVAILABLE, 7 },
    { DXE_PCI_BUS_OUT_OF_RESOURCES, 8},

    {0,0}
};