Toshiba M200-ST2002 Maintenance Manual - Page 60

2 Troubleshooting Procedures 2.4 System Board Troubleshooting Table 2-3 D port status (1/7) D port status F000h F001h Details Clearing software reset bit Enabling address line A20 Initializing special registers and M1535 Initializing the CH0 of a PIT (for HOLD_ON) Initializing flag for BIOS rewriting factor CHECK SUM CHECK (FEFC0000h to FEFF7FFFh) Shifting to protected mode Examining the checksum of Boot Block Examining the checksum of data except Boot Block Checking if EC/KBC firmware is to be rewritten F002h F003h to F005h F006H F007h F008h F009h Executing KBC initializing sequence Sending KBC enable command Checking F12 key-in Initializing security controller Checking whether BIOS rewrite is requested Checking BIOS signature Shifting process to System BIOS IRT side BIOS rewriting process Initializing unique HW for this model Initializing GPIO I/O space Enabling BIOS writing Serial interrupt control Canceling BIOS write protection Enabling SMBus I/O space Enabling SMBus access Configuring DRAM Enabling L1 cache memory Clearing memory Changing ROM BIOS to RAM BIOS Storing key scan codes Setting up TASK_1ms_TSC Displaying message on navipanel (EC/KBC UPDATE, BIOS UPDATE/DAMAGED) Remarks HALT when checksum is not correct. Shifting to BIOS rewriting process if BIOS rewriting request exists Checksum error except Boot Block or rewriting request by F12key-in For BIOS rewriting process 2-22 Portege M200 Maintenance Manual (960-457)