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map multiboot info during boot straping into the address space

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required to support mmio devices as output device during startup
This commit is contained in:
Stefan Lankes 2015-01-17 18:36:32 +01:00
parent 83ea776de8
commit 532c631f85
4 changed files with 42 additions and 6 deletions
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9
arch/x86/include/asm/page.h
View file

@ -110,6 +110,15 @@ size_t virt_to_phys(size_t vir);
*/
int page_init(void);
/** @brief Map one page into the boot page table
*
* @param viraddr
* @param phyaddr
* @param bits
* @return
*/
int page_map_bootmap(size_t viraddr, size_t phyaddr, size_t bits);
/** @brief Map a continuous region of pages
*
* @param viraddr Desired virtual address

17
arch/x86/kernel/entry.asm
View file

@ -65,10 +65,10 @@ stublet:
; Initialize stack pointer
mov esp, boot_stack
add esp, KERNEL_STACK_SIZE-16
; Interpret multiboot information
mov DWORD [mb_info], ebx
; Initialize CPU features
call cpu_init
; Interpret multiboot information
mov DWORD [mb_info], ebx
; Jump to the boot processors's C code
extern main
@ -93,6 +93,15 @@ cpu_init:
mov DWORD [edi], eax
pop edi
%endif
push edi
mov eax, DWORD [mb_info] ; map multiboot info
and eax, 0xFFFFF000 ; page align lower half
mov edi, eax
shr edi, 10 ; (edi >> 12) * 4 (index for boot_pgt)
add edi, boot_pgt
or eax, 0x101 ; set present and global bits
mov DWORD [edi], eax
pop edi
push edi
push ebx
push ecx
@ -106,7 +115,7 @@ L0: cmp ecx, ebx
mov edi, eax
shr edi, 10 ; (edi >> 12) * 4 (index for boot_pgt)
add edi, boot_pgt
or eax, 0x103 ; set present, global, writable and
or eax, 0x103 ; set present, global and writable bits
mov DWORD [edi], eax
add ecx, 0x1000
jmp L0
@ -363,6 +372,8 @@ boot_stack:
; These tables do a simple identity paging and will
; be replaced in page_init() by more fine-granular mappings.
ALIGN 4096
global boot_map
boot_map:
boot_pgd:
DD boot_pgt + 0x107 ; PG_PRESENT | PG_GLOBAL | PG_RW | PG_USER
times 1022 DD 0 ; PAGE_MAP_ENTRIES - 2

2
arch/x86/kernel/uart.c
View file

@ -30,6 +30,7 @@
#include <eduos/string.h>
#include <eduos/mailbox.h>
#include <eduos/ctype.h>
#include <eduos/vma.h>
#include <asm/page.h>
#include <asm/io.h>
#include <asm/page.h>
@ -326,6 +327,7 @@ Lsuccess:
mmio = 1;
page_map(iobase & PAGE_MASK, iobase & PAGE_MASK, 1, PG_GLOBAL | PG_ACCESSED | PG_DIRTY | PG_RW | PG_PCD);
kprintf("UART uses mmio address 0x%x\n", iobase);
vma_add(iobase, iobase + PAGE_SIZE, VMA_READ|VMA_WRITE);
}
// configure uart

20
arch/x86/mm/page.c
View file

@ -55,6 +55,9 @@ extern const void kernel_start;
/** Lock for kernel space page tables */
static spinlock_t kslock = SPINLOCK_INIT;
/** This PGD table is initialized in entry.asm */
extern size_t* boot_map;
/** A self-reference enables direct access to all page tables */
static size_t* self[PAGE_LEVELS] = {
(size_t *) 0xFFC00000,
@ -77,6 +80,16 @@ size_t virt_to_phys(size_t addr)
return phy | off;
}
int page_map_bootmap(size_t viraddr, size_t phyaddr, size_t bits)
{
if (BUILTIN_EXPECT(viraddr >= PAGE_MAP_ENTRIES*PAGE_SIZE, 0))
return -EINVAL;
boot_map[PAGE_MAP_ENTRIES + (viraddr >> PAGE_BITS)] = phyaddr | bits | PG_PRESENT;
return 0;
}
int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits)
{
int lvl, ret = -ENOMEM;
@ -259,9 +272,10 @@ int page_init(void)
/* Map multiboot information and modules */
if (mb_info) {
addr = (size_t) mb_info & PAGE_MASK;
npages = PAGE_FLOOR(sizeof(*mb_info)) >> PAGE_BITS;
page_map(addr, addr, npages, PG_GLOBAL);
// already mapped => entry.asm
//addr = (size_t) mb_info & PAGE_MASK;
//npages = PAGE_FLOOR(sizeof(*mb_info)) >> PAGE_BITS;
//page_map(addr, addr, npages, PG_GLOBAL);
if (mb_info->flags & MULTIBOOT_INFO_MODS) {
addr = mb_info->mods_addr;