x86_64: implement high/low split

1 files changed, 20 insertions, 15 deletions

diff --git a/arch/x86_64/scripts/kernel.ld b/arch/x86_64/scripts/kernel.ld
index 8af242f..6ba8b80 100644
--- a/arch/x86_64/scripts/kernel.ld
+++ b/arch/x86_64/scripts/kernel.ld
@@ -4,6 +4,7 @@ ENTRY(_start)
  * Virtual and linear start addresses of the TeachOS kernel
  *****************************************************************************/
 TEACHOS_PMA = 1M;
+TEACHOS_VMA = 0xFFFFFFFF80000000;
 
 PHDRS {
   boot_rodata PT_LOAD FLAGS(4);
@@ -25,12 +26,13 @@ SECTIONS
   . = TEACHOS_PMA;
 
   /***************************************************************************
-   * We want to be able to be able to access all memory (linear and virtual)
+   * We want to be able to be able to access all memory (physical and virtual)
    * during bootstrapping and operation. To achieve this, we define some
    * symbols at the beginning.
    ***************************************************************************/
   _start_physical = .;
-  _start_virtual = .;
+  _start_virtual = . + TEACHOS_VMA;
+
 
   /***************************************************************************
    * The bootstrapping infratructure goes first. We first place the read-only
@@ -63,7 +65,10 @@ SECTIONS
    * Now it is time to load the 64-bit kernel code. We
    * make sure to align the loaded data onto a page boundary.
    ***************************************************************************/
-  .init ALIGN(4K) : AT(ADDR (.init))
+  . = ALIGN(4K);
+  . += TEACHOS_VMA;
+
+  .init ALIGN(4K) : AT(ADDR(.init) - TEACHOS_VMA)
   {
     /* 
      * Make sure that the crt code is wrapped around the compiler generated
@@ -74,7 +79,7 @@ SECTIONS
     KEEP(*crtn.s.o*(.init))
   } :text
 
-  .fini ALIGN(4K) : AT(ADDR (.fini))
+  .fini ALIGN(4K) : AT(ADDR (.fini) - TEACHOS_VMA)
   {
     /* 
      * Make sure that the crt code is wrapped around the compiler generated
@@ -85,29 +90,29 @@ SECTIONS
     KEEP(*crtn.s.o*(.fini))
   }
 
-  .stl_text ALIGN(4K) : AT(ADDR (.stl_text))
+  .stl_text ALIGN(4K) : AT(ADDR (.stl_text) - TEACHOS_VMA)
   {
     *(.stl_text .stl_text*)
     KEEP(*libstdc++.a:*(.text .text.*))
   }
 
-  .text ALIGN(4K) : AT(ADDR (.text))
+  .text ALIGN(4K) : AT(ADDR (.text) - TEACHOS_VMA)
   {
     *(.text .text.*)
   }
 
-  .user_text ALIGN(4K) : AT(ADDR (.user_text))
+  .user_text ALIGN(4K) : AT(ADDR (.user_text) - TEACHOS_VMA)
   {
     *(.user_text .user_text.*)
   }
 
-  .rodata ALIGN(4K) : AT (ADDR (.rodata))
+  .rodata ALIGN(4K) : AT (ADDR (.rodata) - TEACHOS_VMA)
   {
     *(.rodata)
     *(.rodata.*)
   } :rodata
 
-  .ctors ALIGN(4K) : AT (ADDR (.ctors))
+  .ctors ALIGN(4K) : AT (ADDR (.ctors) - TEACHOS_VMA)
   {
     KEEP(*crtbegin.o(.ctors))
     KEEP(*(EXCLUDE_FILE (*crtend.o) .ctors))
@@ -115,7 +120,7 @@ SECTIONS
     KEEP(*crtend.o(.ctors))
   } :data
 
-  .dtors ALIGN(4K) : AT (ADDR (.dtors))
+  .dtors ALIGN(4K) : AT (ADDR (.dtors) - TEACHOS_VMA)
   {
     KEEP(*crtbegin.o(.dtors))
     KEEP(*(EXCLUDE_FILE (*crtend.o) .dtors))
@@ -123,18 +128,18 @@ SECTIONS
     KEEP(*crtend.o(.dtors))
   }
 
-  .bss ALIGN(4K) : AT (ADDR (.bss))
+  .bss ALIGN(4K) : AT (ADDR (.bss) - TEACHOS_VMA)
   {
     *(COMMON)
     *(.bss*)
   }
 
-  .data ALIGN(4K) : AT (ADDR (.data))
+  .data ALIGN(4K) : AT (ADDR (.data) - TEACHOS_VMA)
   {
     *(.data*)
   }
 
-  .user_data ALIGN(4K) : AT (ADDR (.user_data))
+  .user_data ALIGN(4K) : AT (ADDR (.user_data) - TEACHOS_VMA)
   {
     *(.user_data .user_data.*)
   }
@@ -143,8 +148,8 @@ SECTIONS
    * In accordance with the symbol definitions at the start, we generate some
    * symbols to mark the end of our loaded image.
    ***************************************************************************/
-  _end_virtual = ADDR(.bss) + SIZEOF(.bss);
-  _end_physical = _end_virtual;
+  _end_virtual = .;
+  _end_physical = _end_virtual - TEACHOS_VMA;
 
   /DISCARD/ : { *(.comment) }
 }