merged in removing-assembly branch to do more in C

git-svn-id: svn://anubis/hos/trunk@80 5b3e749e-e535-0410-8002-a9bb6afbdfca

kernel/boot/boot.asm

@@ -1,146 +1,23 @@
-
 ; boot.asm
 ; Author: Josh Holtrop
 ; Date: 2009-06-25
 ; Adapted from HOS 0.16 source
 
-%define MULTIBOOT_HEADER_MAGIC      0x1BADB002
-%define MULTIBOOT_HEADER_FLAGS      0x00000003
-
-%define VIRTUAL_OFFSET              0x00000000          ; kernel virtual addr
 %define CONSOLE_MEMORY              0xB8000
 
-%define PAGE_SIZE                   0x1000              ; 4KB pages
-
-%define KERNEL_STACK_TOP            0xF0000000          ; permanent stack top
-
-; Symbols from the linker
-extern _end, _bss
-
 ; Symbols from C
-extern k_bootstrap, bootstrap_stack, mm_gdtr, k_main
+extern k_bootstrap, bootstrap_stack
 
-;-------------------------------------------------------
-[section .text]
 ;**************************************************************************
 ;* This is the first symbol in the .text section                          *
 ;**************************************************************************
 [global start]
 start:
-
-
-;**************************************************************************
-;* Resume execution                                                       *
-;**************************************************************************
-multiboot_entry:
     mov     cx, 0x0700 + 'a'
     mov     [CONSOLE_MEMORY+160*8+0*2], cx
 
-    lgdt    [gdtr_tmp32-VIRTUAL_OFFSET]     ; load temporary GDTR
+    mov     esp, bootstrap_stack+4096       ; set up temporary stack space
-    jmp     KERNEL_CODE_32_TMP_SEG:segmented_start
 
-
-;**************************************************************************
-;* Multiboot header data block                                            *
-;**************************************************************************
-align 4
-multiboot_header:
-    dd      MULTIBOOT_HEADER_MAGIC                              ; magic
-    dd      MULTIBOOT_HEADER_FLAGS                              ; flags
-    dd      -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)  ; checksum
-
-
-;**************************************************************************
-;* At this point address 0xE000_0000 is mapped to physical address 0x0    *
-;**************************************************************************
-segmented_start:
-    mov     cx, KERNEL_DATA_32_TMP_SEG
-    mov     ss, cx
-    mov     ds, cx
-    mov     es, cx
-    mov     gs, cx
-    mov     fs, cx
-    mov     esp, bootstrap_stack+4096-4     ; set up temporary stack space
-
-    mov     cx, 0x0700 + 'b'
-    mov     [CONSOLE_MEMORY+VIRTUAL_OFFSET+160*8+1*2], cx
-
-    add     ebx, VIRTUAL_OFFSET
     push    eax                             ; multiboot bootloader magic value
     push    ebx                             ; pointer to multiboot info struct
     call    k_bootstrap
-    add     esp, 8
-
-    mov     cx, 0x0700 + 'e'
-    mov     [CONSOLE_MEMORY+VIRTUAL_OFFSET+160*8+4*2], cx
-
-    lgdt    [mm_gdtr]                       ; load permanent GDTR
-    jmp     0x8:segmentation_disabled-VIRTUAL_OFFSET
-
-;**************************************************************************
-;* At this point both segmentation and paging are disabled but we can     *
-;* now enable paging                                                      *
-;**************************************************************************
-segmentation_disabled:
-    mov     cx, 0x10
-    mov     ss, cx
-    mov     ds, cx
-    mov     es, cx
-    mov     gs, cx
-    mov     fs, cx
-
-    ; at this point paging is still disabled but the PDBR is valid and
-    ; points to a page directory that has all of RAM mapped to the
-    ; beginning of the kernel's virtual address space, and the entire
-    ; kernel mapped in above 0xE000_0000.
-
-    ; turn on paging
-    mov     eax, cr0
-    bts     eax, 31
-    mov     cr0, eax
-
-    ; OK, segmentation is disabled and paging is active!
-    mov     cx, 0x0700 + 'f'
-    mov     [CONSOLE_MEMORY+160*8+5*2], cx
-
-    mov     esp, KERNEL_STACK_TOP
-    call    k_main
-
-idle_loop:
-    hlt
-    jmp     idle_loop
-
-
-;-------------------------------------------------------
-[section .rodata]
-gdtr_tmp32:
-    dw      gdt_end_tmp32-gdt_tmp32-1
-    dd      gdt_tmp32-VIRTUAL_OFFSET
-
-gdt_tmp32:              ; 0 = null descriptor
-    dd      0
-    dd      0
-
-    ; a base of 0x2000_0000, when added to 0xE000_0000 will produce
-    ; 0x0000_0000 physical before paging in effect
-KERNEL_CODE_32_TMP_SEG equ $-gdt_tmp32  ; 8
-    db      0xff        ; limit  7:0
-    db      0xff        ; limit  15:8
-    db      0x00        ; base   7:0
-    db      0x00        ; base   15:8
-    db      0x00        ; base   23:16
-    db      0x9a        ; access
-    db      0xcf        ; flags / limit 19:16
-    db      0x00        ; base   31:24
-
-KERNEL_DATA_32_TMP_SEG equ $-gdt_tmp32  ; 16
-    db      0xff        ; limit  7:0
-    db      0xff        ; limit  15:8
-    db      0x00        ; base   7:0
-    db      0x00        ; base   15:8
-    db      0x00        ; base   23:16
-    db      0x92        ; access
-    db      0xcf        ; flags / limit 19:16
-    db      0x00        ; base   31:24
-
-gdt_end_tmp32:

kernel/boot/k_bootstrap.cc

@@ -1,10 +1,11 @@
 
+#include "k_bootstrap.h"
+#include "k_main.h"
 #include "hos_types.h"
 #include "hos_defines.h"
 #include "multiboot.h"
 #include "k_early_panic.h"
 #include "mm/mm.h"
-#include "mm/stack.h"
 #include "lang/kio.h"
 #include "isr/interrupts.h"
 
@@ -16,12 +17,20 @@ extern "C" {
 u8_t bootstrap_stack[4096];
 
 /**************************************************************************
- * This function is invoked before paging is enabled. Segmentation is     *
+ * Multiboot header data block                                            *
- * utilized to map virtual address 0xE000_0000 to physical address 0x0.   *
  *************************************************************************/
-u32_t k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
+u32_t mb_header[] __attribute__ ((section (".multiboot_header") )) = {
+    MB_HEADER_MAGIC,                            /* magic */
+    MB_HEADER_FLAGS,                            /* flags */
+    -(MB_HEADER_MAGIC + MB_HEADER_FLAGS)        /* checksum */
+};
+
+/**************************************************************************
+ * This function is invoked to bootstrap the kernel.                      *
+ *************************************************************************/
+void k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
 {
-    DEBUG_LETTER(2, 'c');
+    DEBUG_LETTER(1, 'b');
 
     if (mb_magic != MB_BOOTLOADER_MAGIC)
     {
@@ -40,7 +49,7 @@ u32_t k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
         mmap = (mb_mmap_t *) (((u32_t)mmap) + mmap->size + 4);
     }
 
-    DEBUG_LETTER(3, 'd');
+    DEBUG_LETTER(2, 'c');
 
     /*
      * These functions could destroy the multiboot information block and
@@ -48,11 +57,27 @@ u32_t k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
      * before calling them.
      */
     mm_bootstrap();
-    stack_bootstrap();
+    DEBUG_LETTER(3, 'd');
     interrupts_bootstrap();
+    DEBUG_LETTER(4, 'e');
     kio_bootstrap();
+    DEBUG_LETTER(5, 'f');
 
-    return 0;
+    __asm__ __volatile__ ("mov $0xF0000000, %%esp;"
+            : /* no outputs */
+            : /* no inputs */
+            : /* no clobbers */);
+    k_main();
+
+    idle_loop();
+}
+
+void idle_loop()
+{
+    for (;;)
+    {
+        __asm__ __volatile__ ("hlt");
+    }
 }
 
 } /* extern "C" */

kernel/boot/k_bootstrap.h

@@ -0,0 +1,17 @@
+
+#ifndef K_BOOTSTRAP_H
+#define K_BOOTSTRAP_H
+
+#include "hos_types.h"
+#include "multiboot.h"
+
+extern "C" {
+
+void k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
+    __attribute__ ((noreturn));
+void idle_loop()
+    __attribute__ ((noreturn));
+
+}
+
+#endif

kernel/boot/k_main.cc

@@ -1,4 +1,5 @@
 
+#include "k_main.h"
 #include "lang/kio.h"
 #include "mm/mm.h"
 #include "sys/timer.h"

kernel/boot/k_main.h

@@ -0,0 +1,11 @@
+
+#ifndef K_MAIN_H
+#define K_MAIN_H
+
+extern "C" {
+
+void k_main();
+
+}
+
+#endif

kernel/include/multiboot.h

@@ -10,6 +10,7 @@ extern "C" {
 
 /* The magic number for the Multiboot header. */
 #define MB_HEADER_MAGIC             0x1BADB002
+#define MB_HEADER_FLAGS             0x00000003
 
 #define MB_HEADER_ALIGN_MODULES     (1 << 0)
 #define MB_HEADER_MEM_INFO          (1 << 1)

kernel/link.ld

@@ -6,6 +6,7 @@ SECTIONS
 {
     .text virt : AT(phys) {
         code = .; _code = .; __code = .;
+        *(.multiboot_header*)
         *(.text*)
         *(.gnu.linkonce*)
         . = ALIGN(4096);

kernel/mm/mm.cc

@@ -154,8 +154,27 @@ void mm_bootstrap()
     mm_gdtr.limit = 3 * sizeof(mm_gdt[0]) - 1;
     mm_gdtr.base = gdt_base;
 
+    __asm__ __volatile__ (
+            "lgdt (mm_gdtr);\n"
+            "jmp $0x08, $42f;\n"
+            "42:\n"
+            "mov $0x10, %%cx\n"
+            "mov %%cx, %%ss\n"
+            "mov %%cx, %%ds\n"
+            "mov %%cx, %%es\n"
+            "mov %%cx, %%fs\n"
+            "mov %%cx, %%gs\n"
+            : /* no outputs */
+            : /* no inputs */
+            : "ecx");
+
     /* set the page directory base register */
-    set_cr3(page_directory);
+    write_cr3(page_directory);
+
+    /* turn on paging */
+    write_cr0(read_cr0() | (1 << 31));
+
+    stack_bootstrap();
 }
 
 /**************************************************************************

kernel/mm/mm.h

@@ -21,17 +21,6 @@ typedef struct
     u64_t   length;
 } mm_mem_range_t;
 
-void mm_record_mmap_entry(mb_mmap_t * mmap);
-void mm_bootstrap();
-
-int mm_early_map(u32_t virtual_address, u32_t physical_address,
-                 u32_t user_mode, u32_t writable);
-int mm_map(u32_t virtual_address, u32_t physical_address,
-           u32_t user_mode, u32_t writable);
-
-u32_t mm_early_page_alloc();
-u32_t mm_page_alloc();
-
 /* http://courses.ece.illinois.edu/ece391/references/descriptors.pdf */
 /* granularity: 0: limit in bytes; 1: limit in pages */
 /* dpl: 0: system mode; 3: user mode */
@@ -50,6 +39,19 @@ u32_t mm_page_alloc();
                 | ( (((u64_t) base) & 0x00FFFFFFull) << 16)  /* base 23:00 */  \
                 | ( (((u64_t) limit) & 0x0000FFFFull) ) )    /* limit 15:00 */
 
+typedef u64_t descriptor_t;
+
+void mm_record_mmap_entry(mb_mmap_t * mmap);
+void mm_bootstrap();
+
+int mm_early_map(u32_t virtual_address, u32_t physical_address,
+                 u32_t user_mode, u32_t writable);
+int mm_map(u32_t virtual_address, u32_t physical_address,
+           u32_t user_mode, u32_t writable);
+
+u32_t mm_early_page_alloc();
+u32_t mm_page_alloc();
+
 void mm_print_memory_map();
 
 #endif

kernel/sys/cpu.h

@@ -4,6 +4,7 @@
 
 #include "hos_types.h"
 
+static u32_t read_cr0() __attribute__ ((unused));
 static u32_t read_cr0()
 {
     u32_t val;
@@ -11,6 +12,7 @@ static u32_t read_cr0()
     return val;
 }
 
+static u32_t read_cr2() __attribute__ ((unused));
 static u32_t read_cr2()
 {
     u32_t val;
@@ -18,6 +20,7 @@ static u32_t read_cr2()
     return val;
 }
 
+static u32_t read_cr3() __attribute__ ((unused));
 static u32_t read_cr3()
 {
     u32_t val;
@@ -25,10 +28,10 @@ static u32_t read_cr3()
     return val;
 }
 
-#define set_cr0(val) \
+#define write_cr0(val) \
     __asm__ __volatile__ ("movl %0, %%cr0" : : "r" (val));
 
-#define set_cr3(val) \
+#define write_cr3(val) \
     __asm__ __volatile__ ("movl %0, %%cr3" : : "r" (val));
 
 #endif