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Added support to map more than 4 MB in the kernel space. This became necessary

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to be able to have more than 1280x1024x8 resolutions. The best solution, however,
would be to map the graphics memory outside of the kernel space, anyway.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@9537 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2004-10-27 16:44:04 +00:00
parent 1b50789288
commit 48ac51f886
1 changed files with 35 additions and 12 deletions
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47
src/kernel/boot/platform/bios_ia32/mmu.cpp
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@ -102,6 +102,28 @@ get_next_physical_page()
}
/** Adds a new page table for the specified base address and makes
* it current, ie. sets sPageTable to point to the new table.
*/
static void
add_page_table(addr_t base)
{
// Get new page table and clear it out
sPageTable = (uint32 *)get_next_physical_page();
if (sPageTable > (uint32 *)(8 * 1024 * 1024))
panic("tried to add page table beyond the indentity mapped 8 MB region\n");
gKernelArgs.arch_args.pgtables[gKernelArgs.arch_args.num_pgtables++] = (uint32)sPageTable;
for (int32 i = 0; i < 1024; i++)
sPageTable[i] = 0;
// put the new page table into the page directory
sPageDirectory[base/(4*1024*1024)] = (uint32)sPageTable | kDefaultPageFlags;
}
/** Creates an entry to map the specified virtualAddress to the given
* physicalAddress.
* Note, it can only map the 4 meg region right after KERNEL_BASE; this
@ -114,9 +136,19 @@ map_page(addr_t virtualAddress, addr_t physicalAddress, uint32 flags)
{
TRACE(("map_page: vaddr 0x%lx, paddr 0x%lx\n", virtualAddress, physicalAddress));
if (virtualAddress < KERNEL_BASE || virtualAddress >= sMaxVirtualAddress)
if (virtualAddress < KERNEL_BASE)
panic("map_page: asked to map invalid page %p!\n", (void *)virtualAddress);
if (virtualAddress >= sMaxVirtualAddress) {
// we need to add a new page table
add_page_table(sMaxVirtualAddress);
sMaxVirtualAddress += B_PAGE_SIZE * 1024;
if (virtualAddress >= sMaxVirtualAddress)
panic("map_page: asked to map a page to %p\n", (void *)virtualAddress);
}
physicalAddress &= ~(B_PAGE_SIZE - 1);
TRACE(("paddr 0x%lx @ index %ld\n", physicalAddress,
@ -214,17 +246,8 @@ init_page_directory()
sPageDirectory[1] = (uint32)pgtable | kDefaultPageFlags;
// Get new page table and clear it out
sPageTable = (uint32 *)get_next_physical_page();
gKernelArgs.arch_args.pgtables[0] = (uint32)sPageTable;
gKernelArgs.arch_args.num_pgtables = 1;
for (int32 i = 0; i < 1024; i++)
sPageTable[i] = 0;
// put the new page table into the page directory
// this maps the kernel at KERNEL_BASE
sPageDirectory[KERNEL_BASE/(4*1024*1024)] = (uint32)sPageTable | kDefaultPageFlags;
gKernelArgs.arch_args.num_pgtables = 0;
add_page_table(KERNEL_BASE);
// switch to the new pgdir and enable paging
asm("movl %0, %%eax;"