From 02773ed2f47e8300917317860dd20cc94d2fd7c3 Mon Sep 17 00:00:00 2001
From: WangRunji <wangrunji0408@163.com>
Date: Fri, 13 Apr 2018 14:21:09 +0800
Subject: [PATCH] Move kernel virtual address to high zone. Change asm.

---
 src/arch/x86_64/boot/boot.asm           |  9 +++---
 src/arch/x86_64/boot/linker.ld          | 41 +++++++++++++++++++------
 src/arch/x86_64/boot/long_mode_init.asm |  5 +--
 3 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/src/arch/x86_64/boot/boot.asm b/src/arch/x86_64/boot/boot.asm
index c82b6df..cc5dca3 100644
--- a/src/arch/x86_64/boot/boot.asm
+++ b/src/arch/x86_64/boot/boot.asm
@@ -1,7 +1,7 @@
 global start
 extern long_mode_start
 
-section .text
+section .text32
 bits 32
 start:
     mov esp, stack_top
@@ -90,10 +90,11 @@ set_up_page_tables:
     or eax, 0b11 ; present + writable
     mov [p4_table + 511 * 8], eax
 
-    ; map first P4 entry to P3 table
+    ; map first & 510th P4 entry to P3 table
     mov eax, p3_table
     or eax, 0b11 ; present + writable
     mov [p4_table], eax
+    mov [p4_table + 510 * 8], eax
 
     ; map first P3 entry to P2 table
     mov eax, p2_table
@@ -148,7 +149,7 @@ error:
     mov byte  [0xb800a], al
     hlt
 
-section .bss
+section .bss32
 align 4096
 p4_table:
     resb 4096
@@ -160,7 +161,7 @@ stack_bottom:
     resb 4096 * 4
 stack_top:
 
-section .rodata
+section .rodata32
 gdt64:
     dq 0 ; zero entry
 .code: equ $ - gdt64 ; new
diff --git a/src/arch/x86_64/boot/linker.ld b/src/arch/x86_64/boot/linker.ld
index 5b58518..86d17ec 100644
--- a/src/arch/x86_64/boot/linker.ld
+++ b/src/arch/x86_64/boot/linker.ld
@@ -1,52 +1,75 @@
 ENTRY(start)
 
+BOOT_OFFSET = 0x100000;
+KERNEL_OFFSET = 0xffffff0000000000;
+
 SECTIONS {
-  . = 1M;
+  . = BOOT_OFFSET;
 
-  .rodata :
+  .rodata32 :
   {
     /* ensure that the multiboot header is at the beginning */
     KEEP(*(.multiboot_header))
+    *(.rodata32 .rodata32.*)
+    . = ALIGN(4K);
+  }
+  .text32 :
+  {
+    *(.text32 .text32.*)
+    . = ALIGN(4K);
+  }
+  .bss32 :
+  {
+    *(.bss32 .bss32.*)
+    . = ALIGN(4K);
+  }
+
+  . += KERNEL_OFFSET;
+
+  .rodata : AT(ADDR(.rodata) - KERNEL_OFFSET)
+  {
     *(.rodata .rodata.*)
     . = ALIGN(4K);
   }
 
-  .text :
+  .text : AT(ADDR(.text) - KERNEL_OFFSET)
   {
     *(.text .text.*)
     . = ALIGN(4K);
   }
 
-  .data :
+  .data : AT(ADDR(.data) - KERNEL_OFFSET)
   {
     *(.data .data.*)
     . = ALIGN(4K);
   }
 
-  .bss :
+  .bss : AT(ADDR(.bss) - KERNEL_OFFSET)
   {
     *(.bss .bss.*)
     . = ALIGN(4K);
   }
 
-  .got :
+  .got : AT(ADDR(.got) - KERNEL_OFFSET)
   {
     *(.got)
     . = ALIGN(4K);
   }
 
-  .got.plt :
+  .got.plt : AT(ADDR(.got.plt) - KERNEL_OFFSET)
   {
     *(.got.plt)
     . = ALIGN(4K);
   }
 
-  .data.rel.ro : ALIGN(4K) {
+  .data.rel.ro : AT(ADDR(.data.rel.ro) - KERNEL_OFFSET) 
+  {
     *(.data.rel.ro.local*) *(.data.rel.ro .data.rel.ro.*)
     . = ALIGN(4K);
   }
 
-  .gcc_except_table : ALIGN(4K) {
+  .gcc_except_table : AT(ADDR(.gcc_except_table) - KERNEL_OFFSET)
+  {
     *(.gcc_except_table)
     . = ALIGN(4K);
   }
diff --git a/src/arch/x86_64/boot/long_mode_init.asm b/src/arch/x86_64/boot/long_mode_init.asm
index 00b6b22..61b96d9 100644
--- a/src/arch/x86_64/boot/long_mode_init.asm
+++ b/src/arch/x86_64/boot/long_mode_init.asm
@@ -1,7 +1,7 @@
 global long_mode_start
 extern rust_main
 
-section .text
+section .text32
 bits 64
 long_mode_start:
     ; load 0 into all data segment registers
@@ -14,7 +14,8 @@ long_mode_start:
 
     ; call the rust main
     extern rust_main
-    call rust_main
+    mov rax, rust_main
+    call rax
 
     ; print `OKAY` to screen
     mov rax, 0x2f592f412f4b2f4f