[FREELDR] Limit the usage of DiskStopFloppyMotor() in hardware/platform-specific...

[reactos.git] / boot / freeldr / freeldr / arch / amd64 / entry.S

diff --git a/boot/freeldr/freeldr/arch/amd64/entry.S b/boot/freeldr/freeldr/arch/amd64/entry.S
index 9390520..31c6411 100644 (file)
--- a/boot/freeldr/freeldr/arch/amd64/entry.S
+++ b/boot/freeldr/freeldr/arch/amd64/entry.S
@@ -1,9 +1,16 @@
 
-
 #include <asm.inc>
 #include <arch/pc/x86common.h>
 
 EXTERN BootMain:PROC
+// EXTERN cmdline:DWORD
+
+EXTERN DiskStopFloppyMotor:PROC
+
+#ifdef _USE_ML
+EXTERN __bss_start__:FWORD
+EXTERN __bss_end__:FWORD
+#endif
 
 .code64
 
@@ -26,7 +33,7 @@ RealEntryPoint:
     jmp qword ptr [ContinueAddress]
 
 ContinueAddress:
-    .double offset FrldrStartup
+    .quad offset FrldrStartup
 
 FrldrStartup:
 
@@ -41,15 +48,89 @@ FrldrStartup:
     mov eax, dword ptr [BSS_RealModeEntry]
     mov dword ptr [AddressOfRealModeEntryPoint], eax
 
-    /* GO! */
+    /* Clean out BSS */
+    xor rax, rax
+    mov rdi, offset __bss_start__
+    mov rcx, offset __bss_end__ + 7
+    sub rcx, rdi
+    shr rcx, 3
+    rep stosq
+
+    /* Pass the command line to BootMain */
+    // mov rcx, offset cmdline
     xor rcx, rcx
+
+    /* GO! */
     call BootMain
 
-       /* We should never get here */
+    /* We should never get here */
 stop:
-       jmp     stop
-       nop
-       nop
+    jmp short stop
+    nop
+    nop
+
+
+PUBLIC Reboot
+Reboot:
+    /* Stop the floppy drive motor */
+    call DiskStopFloppyMotor
+
+    /* Set the function ID */
+    mov bx, FNID_Reboot
+
+    /* Switch to real mode (we don't return) */
+    jmp SwitchToReal
+
+
+/*
+ * VOID __cdecl ChainLoadBiosBootSectorCode(
+ *     IN UCHAR BootDrive OPTIONAL,
+ *     IN ULONG BootPartition OPTIONAL);
+ *
+ * RETURNS: Nothing
+ */
+PUBLIC ChainLoadBiosBootSectorCode
+ChainLoadBiosBootSectorCode:
+    /* Set the boot drive */
+    mov dl, [esp + 4]
+    test dl, dl
+    jnz set_part
+    mov dl, byte ptr [FrldrBootDrive]
+
+    /* Set the boot partition */
+set_part:
+    mov eax, [esp + 8]
+    test eax, eax
+    jnz continue
+    mov eax, dword ptr [FrldrBootPartition]
+continue:
+    /* Store the 1-byte truncated partition number in DH */
+    mov dh, al
+
+    /*
+     * Don't stop the floppy drive motor when we are just booting a bootsector,
+     * a drive, or a partition. If we were to stop the floppy motor, the BIOS
+     * wouldn't be informed and if the next read is to a floppy then the BIOS
+     * will still think the motor is on and this will result in a read error.
+     */
+    // call DiskStopFloppyMotor
+
+    /* Set the function ID */
+    mov bx, FNID_ChainLoadBiosBootSectorCode
+
+    /* Switch to real mode (we don't return) */
+    jmp SwitchToReal
+
+
+/*
+ * U16 PxeCallApi(U16 Segment, U16 Offset, U16 Service, VOID *Parameter);
+ *
+ * RETURNS:
+ */
+PUBLIC PxeCallApi
+PxeCallApi:
+    xor eax, eax
+    ret
 
 
 /* Internal function for realmode calls
@@ -65,17 +146,17 @@ CallRealMode:
 
 SwitchToReal:
     /* Set sane segments */
-       mov ax, LMODE_DS
-       mov ds, ax
-       mov es, ax
-       mov fs, ax
-       mov gs, ax
-       //mov ss, ax
+    mov ax, LMODE_DS
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+    //mov ss, ax
 
     //mov word ptr [HEX(0b8008)], HEX(0e00) + '4'
 
-       /* Save 64-bit stack pointer */
-       mov qword ptr [stack64], rsp
+    /* Save 64-bit stack pointer */
+    mov qword ptr [stack64], rsp
 
     /* Step 1 - jump to compatibility segment */
     jmp fword ptr [jumpvector]
@@ -88,15 +169,15 @@ SwitchToRealCompSegment:
     /* Note: In fact the CPU is in 32 bit mode here. But it will interprete
        the generated instructions accordingly. rax will become eax */
 
-       /* Step 2 - deactivate long mode, by disabling paging */
-       mov rax, cr0
-       and eax, HEX(7fffffff) //~0x80000000, upper bits cleared
-       mov cr0, rax
+    /* Step 2 - deactivate long mode, by disabling paging */
+    mov rax, cr0
+    and eax, HEX(7fffffff) //~0x80000000, upper bits cleared
+    mov cr0, rax
 
 //    mov word ptr [HEX(0b800a)], HEX(0e00) + '5'
 
-       /* Step 3 - jump to 16-bit segment to set the limit correctly */
-       .byte HEX(0EA) // 32bit long jmp
+    /* Step 3 - jump to 16-bit segment to set the limit correctly */
+    .byte HEX(0EA) // 32bit long jmp
 AddressOfRealModeEntryPoint:
     .long 0 // receives address of RealModeEntryPoint
     .word HEX(20)//RMODE_CS
@@ -110,23 +191,6 @@ CallRealMode_return:
 /////////////////////////////////////////
 
 
-       /* 64-bit stack pointer */
-stack64:
-    .double STACK64ADDR
-
-PUBLIC FrldrBootDrive
-FrldrBootDrive:
-    .byte 0
-
-PUBLIC FrldrBootPartition
-FrldrBootPartition:
-    .long 0
-
-PUBLIC PxeCallApi
-PxeCallApi:
-    xor eax, eax
-    ret
-
 //void __lgdt(void *Source);
 PUBLIC __lgdt
 __lgdt:
@@ -140,4 +204,16 @@ __ltr:
     ret
 
 
+    /* 64-bit stack pointer */
+stack64:
+    .quad STACKADDR
+
+PUBLIC FrldrBootDrive
+FrldrBootDrive:
+    .byte 0
+
+PUBLIC FrldrBootPartition
+FrldrBootPartition:
+    .long 0
+
 END