Changeset dcbc8be in mainline for arch/ia32/src

Timestamp:

2005-06-02T23:56:26Z (20 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ac5d02b

Parents:

7dcbc0a1

Message:

Big changes in IA-32 address space map.
Now the kernel is mapped above 0x80000000. Finally!
Userspace address space starts at 0x00000000.
Changes in many places.
This improvement temporarily breaks SMP and most likely also other stuff.
Supported size of memory is now only 4M as it is the biggest size that can be mapped at once on IA-32.

Changes in linker script.
Changes required because of the above.
Do not patch hardcoded_* variables but assign to them instead.

Cosmetic changes here and there.

Location:

arch/ia32/src

Files:

• boot/boot.S (modified) (2 diffs)
• boot/memmap.S (modified) (1 diff)
• mm/frame.c (modified) (1 diff)
• mm/page.c (modified) (5 diffs)
• pm.c (modified) (2 diffs)

arch/ia32/src/boot/boot.S

@@ -40 +40 @@
 #
 kernel_image_start:
+        cli
         call memmap_arch_init
-        cli
         xorw %ax,%ax
         movw %ax,%ds
@@ -63 +63 @@
         lidt idtr
 
+        #
+        # Here we setup mapping for both the unmapped and mapped sections of the kernel.
+        # For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000.
+        #
+        movl %cr4, %ecx
+        orl $(1<<4), %ecx
+        movl %ecx, %cr4                         # turn PSE on
+        
+        movl $((1<<7)|(1<<0)), %eax
+        movl %eax, page_directory               # mapping 0x00000000 => 0x00000000
+
+        movl $(page_directory+(4096/2)), %edx
+        movl %eax, (%edx)                       # mapping 0x80000000 => 0x00000000
+
+        leal page_directory, %eax
+        movl %eax, %cr3
+        
+        # turn on paging
+        movl %cr0, %ebx
+        orl $(1<<31), %ebx
+        movl %ebx, %cr0
+
+        movl $_hardcoded_ktext_size, hardcoded_ktext_size
+        movl $_hardcoded_kdata_size, hardcoded_kdata_size
+        movl $_hardcoded_load_address, hardcoded_load_address
+
         call main_bsp                   # never returns
-        
 
         cli
         hlt
+
+.section K_DATA_START
+
+.align 4096
+page_directory:
+        .space 4096, 0

arch/ia32/src/boot/memmap.S

@@ -29 +29 @@
 
 #include <arch/boot/memmap.h>
-
-.global memmap_arch_init
-
-.code16
-.section K_TEXT_START
-
 
 E820_RECORD_SIZE = MEMMAP_E820_RECORD_SIZE

arch/ia32/src/mm/frame.c

@@ -38 +38 @@
 {
         if (config.cpu_active == 1) {
-                __u32 kernel_frames_max;
-                
-                kernel_frames_max = ((KERNEL_ADDRESS_SPACE_END+1)/FRAME_SIZE);
-                
-                kernel_frames_free = kernel_frames = frames < kernel_frames_max ? frames : kernel_frames_max;
+                kernel_frames = frames;
+                kernel_frames_free = frames_free;
                 frame_kernel_bitmap = frame_bitmap;
 

arch/ia32/src/mm/page.c

@@ -54 +54 @@
 
         if (config.cpu_active == 1) {
-                dba = frame_alloc(FRAME_KA | FRAME_PANIC);
+                dba = KA2PA(frame_alloc(FRAME_KA | FRAME_PANIC));
                 memsetb(dba, PAGE_SIZE, 0);
-                cpu_write_dba(dba);
             
                 bootstrap_dba = dba;
@@ -62 +61 @@
                 /*
                  * Identity mapping for all but 0th page.
+                 * PA2KA(identity) mapping for all but 0th page.
                  */
-                for (i = 1; i < frames; i++)
+                for (i = 1; i < frames; i++) {
                         map_page_to_frame(i * PAGE_SIZE, i * PAGE_SIZE, PAGE_CACHEABLE, 0);
+                        map_page_to_frame(PA2KA(i * PAGE_SIZE), i * PAGE_SIZE, PAGE_CACHEABLE, 0);                      
+                }
 
                 trap_register(14, page_fault);
+                cpu_write_dba(dba);             
         }
         else {
@@ -105 +108 @@
         int pde, pte;
 
-        dba = cpu_read_dba();
+//      TODO: map_page_to_frame should take dba as a parameter
+//      dba = cpu_read_dba();
+        dba = bootstrap_dba;
 
         pde = page >> 22;               /* page directory entry */
@@ -117 +122 @@
                  * frame for the page table and clean it.
                  */
-                newpt = frame_alloc(FRAME_KA);
+                newpt = KA2PA(frame_alloc(FRAME_KA));
                 pd[pde].frame_address = newpt >> 12;
                 memsetb(newpt, PAGE_SIZE, 0);
@@ -124 +129 @@
         }
         if (copy) {
-                newpt = frame_alloc(FRAME_KA);
+                newpt = KA2PA(frame_alloc(FRAME_KA));
                 memcopy(pd[pde].frame_address << 12, newpt, PAGE_SIZE);
                 pd[pde].frame_address = newpt >> 12;

arch/ia32/src/pm.c

@@ -67 +67 @@
 
 /* gdtr is changed by kmp before next CPU is initialized */
-struct ptr_16_32 gdtr __attribute__ ((section ("K_DATA_START"))) = { .limit = sizeof(gdt), .base = (__address) gdt };
-struct ptr_16_32 idtr __attribute__ ((section ("K_DATA_START")))= { .limit = sizeof(idt), .base = (__address) idt };
+struct ptr_16_32 gdtr __attribute__ ((section ("K_DATA_START"))) = { .limit = sizeof(gdt), .base = KA2PA((__address) gdt) };
+struct ptr_16_32 idtr __attribute__ ((section ("K_DATA_START"))) = { .limit = sizeof(idt), .base = KA2PA((__address) idt) };
 
 void gdt_setbase(struct descriptor *d, __address base)
 {
-        d->base_0_15 = base & 0xffff;
-        d->base_16_23 = (base >> 16) & 0xff;
-        d->base_24_31 = (base >> 24) & 0xff;
+        d->base_0_15 = KA2PA(base) & 0xffff;
+        d->base_16_23 = (KA2PA(base) >> 16) & 0xff;
+        d->base_24_31 = (KA2PA(base) >> 24) & 0xff;
 }
 
-void gdt_setlimit(struct descriptor *d, __address limit)
+void gdt_setlimit(struct descriptor *d, __u32 limit)
 {
         d->limit_0_15 = limit & 0xffff;
@@ -85 +85 @@
 void idt_setoffset(struct idescriptor *d, __address offset)
 {
-        d->offset_0_15 = offset & 0xffff;
-        d->offset_16_31 = offset >> 16;
+        d->offset_0_15 = KA2PA(offset) & 0xffff;
+        d->offset_16_31 = KA2PA(offset) >> 16;
 }