hschumann2/TempleOS-Source-Code

1 2asm {/* See ::/Doc/Boot.DD.3TempleOS starts in real, calls some BIOS4routines, switches to 32 bit, and 64 bit mode5and continues in HolyC at KMain().6 7The boot loader jumps here in real-mode (16-bit).8It actually jumps to the CBinFile header which is9placed just before this by the compiler.10The header begins with a short jmp to11the start of this file's code which begins12with the following small jump past some data.13 14This file is first in the Kernel image15because it is #included first.  Kernel.PRJ16*/17USE1618SYS_KERNEL:: //This must match CKernel.19        JMP     I16 CORE0_16BIT_INIT20 21//************************************22//  ASM Global vars required for 16-bit start-up23        ALIGN   4,OC_NOP24SYS_BOOT_SRC::                  DU32    BOOT_SRC_NULL;25SYS_BOOT_BLK::                  DU32    0;26SYS_BOOT_PATCH_TABLE_BASE::     DU32    0;27SYS_RUN_LEVEL::                 DU32    0;28#exe {StreamPrint("SYS_COMPILE_TIME:: DU64 0x%X;",Now);} //See BootDVDProbe29#assert SYS_COMPILE_TIME+sizeof(CDate)+sizeof(CBinFile)<DVD_BLK_SIZE30 31MEM_BOOT_BASE::         DU32    0;      //Offset from start used by reboot32MEM_E801::              DU16    0,0;33MEM_E820::              DU8     MEM_E820_ENTRIES_NUM*sizeof(CMemE820) DUP (0);34MEM_PHYSICAL_SPACE::    DU64    0;35SYS_GDT_PTR::           DU16    sizeof(CGDT)-1;36                        DU64    0;37SYS_PCI_BUSES::         DU16    0;38 39        ALIGN   16,OC_NOP40SYS_GDT:: //See CGDT41GDT_NULL:       DU64    0,0;42GDT_BOOT_DS:    DU64    0x00CF92000000FFFF,0; //Gets patched.43GDT_BOOT_CS:    DU64    0x00CF9A000000FFFF,0; //Gets patched.44GDT_CS32:       DU64    0x00CF9A000000FFFF,0;45GDT_CS64:       DU64    0x00209A0000000000,0; //The Charter says just ring0.46GDT_CS64_RING3: DU64    0x0020FA0000000000,0; //Ring3, so you can play with.47GDT_DS:         DU64    0x00CF92000000FFFF,0;48GDT_DS_RING3:   DU64    0x00CFF2000000FFFF,0;49GDT_TR:         DU8     MP_PROCESSORS_NUM*16 DUP(0);50GDT_TR_RING3:   DU8     MP_PROCESSORS_NUM*16 DUP(0);51#assert $-SYS_GDT==sizeof(CGDT)52 53#assert $-SYS_KERNEL==sizeof(CKernel)-sizeof(CBinFile)54 55//************************************56CORE0_16BIT_INIT::57//EAX is SYS_BOOT_SRC. (Val passed from boot blk, BootHD, BootDVD, & BootRAM.)58        MOV     ECX,EAX59        MOV     AX,(BOOT_RAM_LIMIT-BOOT_STK_SIZE)/1660        MOV     SS,AX61        MOV     SP,BOOT_STK_SIZE62        PUSH    ECX     //Will be SYS_BOOT_SRC. See BootHD, BootDVD & BootRAM.63        PUSH    EBX64 65        CALL    U16 GET_RIP66GET_RIP:        POP     BX67        SUB     BX,GET_RIP68        SHR     BX,469        MOV     AX,CS70        ADD     AX,BX71        PUSH    AX72        PUSH    U16 @@0573        RETF74 75@@05:   STI76        MOV     AX,CS77        MOV     DS,AX78 79        MOV     U32 [SYS_RUN_LEVEL],RLF_16BIT80 81        MOV     AX,0x4F0282        MOV     BX,0x12         //640x480 16 color83#exe {84  if (!kernel_cfg->opts[CFG_TEXT_MODE])85    StreamPrint("INT 0x10");    //Enable VGA86};87        CMP     AX,0x004F88        JNE     @@10            //Jmp if fail89        BTS     U32 [SYS_RUN_LEVEL],RLf_VGA90@@10:91 92//Get mem maps.93        MOV     AX,0xE80194        INT     0x1595        MOV     U16 [MEM_E801],CX96        MOV     U16 [MEM_E801+2],DX97 98        MOV     CX,MEM_E820_ENTRIES_NUM-1 //Leave one to terminate99        XOR     EBX,EBX100        MOV     AX,DS101        MOV     ES,AX102        MOV     DI,MEM_E820103@@15:   PUSH    CX104        MOV     EAX,0xE820105        MOV     ECX,sizeof(CMemE820)106        MOV     EDX,'PAMS'107        INT     0x15108        JC      @@20109        CMP     EAX,'PAMS'110        JNE     @@20111        TEST    EBX,EBX112        JZ      @@20113        ADD     DI,sizeof(CMemE820)114        POP     CX115        LOOP    @@15116        SUB     SP,2117@@20:   ADD     SP,2118 119//Find how much space to map, start with E801 limit.120        XOR     EAX,EAX121        MOV     AX,[MEM_E801+2]122        SHL     EAX,16123        ADD     EAX,SYS_16MEG_AREA_LIMIT124        XOR     EDX,EDX125 126//Find max of E820 to set mapped space.127        MOV     SI,MEM_E820128@@25:   MOV     CL,CMemE820.type[SI]129        TEST    CL,CL130        JZ      @@35131        MOV     EBX,CMemE820.base[SI]132        MOV     ECX,CMemE820.base+4[SI]133        ADD     EBX,CMemE820.len[SI]134        ADC     ECX,CMemE820.len+4[SI]135        SUB     EBX,EAX136        SBB     ECX,EDX137        JC      @@30138        MOV     EAX,CMemE820.base[SI]139        MOV     EDX,CMemE820.base+4[SI]140        ADD     EAX,CMemE820.len[SI]141        ADC     EDX,CMemE820.len+4[SI]142@@30:   ADD     SI,sizeof(CMemE820)143        JMP     @@25144 145@@35:   MOV     [MEM_PHYSICAL_SPACE],EAX146        MOV     [MEM_PHYSICAL_SPACE+4],EDX147 148//Get PCI Bus Info149        MOV     U16 [SYS_PCI_BUSES],256150        XOR     DX,DX151        MOV     AX,0xB101152        INT     0x1A153        CMP     DX,'PC'154        JNE     @@40155        MOV     CH,0156        INC     CX157        MOV     U16 [SYS_PCI_BUSES],CX158@@40:159        CLI160//Enable A20161        IN      AL,0x92162        OR      AL,2163        OUT     0x92,AL164 165        POP     U32 [SYS_BOOT_BLK]166        POP     U32 [SYS_BOOT_SRC]      //See BootHD, BootDVD, & BootRAM.167 168        CLD169        XOR     EAX,EAX170        MOV     AX,CS171        MOV     DS,AX172        MOV     ES,AX173        SHL     EAX,4174 175        MOV     U32 [MEM_BOOT_BASE],EAX176 177        MOV     DX,CS178        SUB     DX,sizeof(CBinFile)/16179#assert !(sizeof(CBinFile)&15)180        MOV     GS,DX181 182        MOV     EDX,EAX183        ADD     EDX,U32 GS:[CBinFile.patch_table_offset]184        SUB     EDX,sizeof(CBinFile)185        MOV     U32 [SYS_BOOT_PATCH_TABLE_BASE],EDX186 187        ADD     U32 [GDT_BOOT_DS+2],EAX188        ADD     U32 [GDT_BOOT_CS+2],EAX189        ADD     EAX,I32 SYS_GDT190        MOV     U32 [SYS_GDT_PTR+CSysLimitBase.base],EAX191        LGDT    U32 [SYS_GDT_PTR]192 193        MOV     EAX,SYS_START_CR0194        MOV_CR0_EAX195 196/* The assembler doesn't support far jumps so197we hand code it.  16-bit code is not important198enough to fully implement in the assembler.199 200To complete the switch to 32-bit mode, we have to load201the code segment with a far jump.202*/203        DU8     0x66,0xEA; //JMP CGDT.boot_cs:CORE0_32BIT_INIT204        DU32    CORE0_32BIT_INIT;205        DU16    CGDT.boot_cs;206#assert $+16<=0xFFFF207}208