Moved the kernel to 1MiB (to avoid problems with low memory-mapped IO).

Also had to change the low mapping to 2GiB instead of 2MiB, because the stack finished after 2MiB.

diff --git a/linker.ld b/linker.ld
index 60de5eb000614e0299dc79d1fd06c2bee8fe5ce0..7c4e9f6a66f0db9cf44741ac0edb23858645a7f2 100644 (file)
--- a/linker.ld
+++ b/linker.ld
@@ -3,6 +3,8 @@ ENTRY(_start)
 KERNEL_VMA = 0xFFFFFFFF80000000;
 SECTIONS {
 
+       . = 1M;
+
        .bootstrap ALIGN(4K) : {
                *(.multiboot_header)
                . = ALIGN(4K);

diff --git a/src/boot.S b/src/boot.S
index e745a0f7031394df42567a906d845f222323aa2c..53a9162ff96e021c95acb9e0b8fea453e1f60ad7 100644 (file)
--- a/src/boot.S
+++ b/src/boot.S
@@ -77,16 +77,21 @@ TSS:
 TSS_END:
 .set TSS_SIZE, TSS_END - TSS
 .align 0x1000
+#TODO replace with actual RAM detection
+.globl test_ram
+test_ram: .quad 256
+          .quad 0
+          .skip 0x1000 * 256 - 16 # 1MiB RAM
+PDPT_low:  .quad 0x83
+           .quad 0x83 + 1024 * 1024 * 1024
+           .skip 0x1000 - 16
 PDPT_high: .skip 0x1000 - 16
            .quad 0x83
            .quad 0x83 + 1024 * 1024 * 1024
 
 .section .bss
 .align 0x1000
-PML4T:     .skip 0x1000
-PDPT_low:  .skip 0x1000
-PDT:       .skip 0x1000
-PT:        .skip 0x1000
+PML4T: .skip 0x1000
 phys_mem_map: .skip 0x1000 * 128 - 8
 .align 16
 stack_bottom:
@@ -152,21 +157,9 @@ _start:
        mov $PML4T - KERNEL_VMA, %eax
        mov %eax, %cr3
        mov $PDPT_low - KERNEL_VMA + 3, %eax
-       mov %eax, PML4T - KERNEL_VMA + 0 * 8
+       mov %eax, PML4T - KERNEL_VMA +   0 * 8
        mov $PDPT_high - KERNEL_VMA + 3, %eax
        mov %eax, PML4T - KERNEL_VMA + 511 * 8
-       mov $PDT - KERNEL_VMA + 3, %eax
-       mov %eax, PDPT_low - KERNEL_VMA + 0 * 8
-       mov $PT - KERNEL_VMA + 3, %eax
-       mov %eax, PDT - KERNEL_VMA + 0 * 8
-
-       mov $PT - KERNEL_VMA, %edi
-       mov $0x0003, %ebx
-       mov $512, %ecx
-1:     mov %ebx, (%edi)
-       add $0x1000, %ebx
-       add $8, %edi
-       loop 1b
 
        # Enable PAE paging:
        mov %cr4, %eax