[FREELDR] Introduce a MSVC "linker script" file that centralizes the commands for...

[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 9379008..e5620bd 100644 (file)
--- a/boot/freeldr/freeldr/arch/amd64/entry.S
+++ b/boot/freeldr/freeldr/arch/amd64/entry.S
@@ -1,9 +1,14 @@
 
-
 #include <asm.inc>
 #include <arch/pc/x86common.h>
 
 EXTERN BootMain:PROC
+// EXTERN cmdline:DWORD
+
+#ifdef _USE_ML
+EXTERN __bss_start__:FWORD
+EXTERN __bss_end__:FWORD
+#endif
 
 .code64
 
@@ -26,7 +31,7 @@ RealEntryPoint:
     jmp qword ptr [ContinueAddress]
 
 ContinueAddress:
-    .double offset FrldrStartup
+    .quad offset FrldrStartup
 
 FrldrStartup:
 
@@ -41,15 +46,26 @@ 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
@@ -74,17 +90,17 @@ 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]
@@ -97,15 +113,15 @@ 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
@@ -119,9 +135,9 @@ CallRealMode_return:
 /////////////////////////////////////////
 
 
-       /* 64-bit stack pointer */
+    /* 64-bit stack pointer */
 stack64:
-    .double STACK64ADDR
+    .quad STACKADDR
 
 PUBLIC FrldrBootDrive
 FrldrBootDrive: