[haiku-bugs] Re: [Haiku] #11896: ARM: arch_mmu assumes RAM starts at 80000000
- From: "kallisti5" <trac@xxxxxxxxxxxx>
- Date: Thu, 12 Mar 2015 12:13:17 -0000
#11896: ARM: arch_mmu assumes RAM starts at 80000000
------------------------------+--------------------------------------------
Reporter: kallisti5 | Owner: pdziepak
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: System/Boot | Version: R1/Development
Loader | Keywords: ARM MMU pfoetchen mmu_man rpi2
Resolution: | Blocking:
Blocked By: | Platform: arm
Has a Patch: 0 |
------------------------------+--------------------------------------------
Comment (by kallisti5):
Actually, looking at mmu_man's comments... this makes sense.
dynamic allocation is at the PageTableRegionEnd...
{{{
// allocate page directory in memory after loader
sPageDirectory = (uint32 *)ROUNDUP((addr_t)&_end, 0x100000);
sNextPageTableAddress = (addr_t)sPageDirectory +
ARM_MMU_L1_TABLE_SIZE;
sPageTableRegionEnd = (addr_t)sPageDirectory + 0x200000;
// Mark start for dynamic allocation
sNextPhysicalAddress =
sNextVirtualAddress = sPageTableRegionEnd;
}}}
So:
* loader 80000 - d0000
* insert_physical_allocated_range
* pageDirectory 100000 - 300000
* insert_physical_allocated_range
* dynamicAllocation 300000+
* init_page_directory();
* mmu_map_identity loader 80000 - d0000
* mmu_map_identity pageDirectory 100000 - 300000
This all means the first map_page request for a dynamic range coming in
fails..
{{{
mmu_allocate: requested vaddr: 0x00000000, next free vaddr: 0x300000,
size: 16384
map_page: vaddr 0x300000, paddr 0x300000
*** PANIC ***
*** PANIC ***
map_page: asked to map invalid page 0x00300000!
map_page: asked to map invalid page 0x00300000!
}}}
mmu_allocate says the first virtual memory for the dynamic range is
0x300000... is that right?
{{{
static void
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_LOAD_BASE) {
panic("map_page: asked to map invalid page %p!\n",
(void *)virtualAddress);
}
}}}
headers/private/kernel/arch/arm/arch_kernel.h:#define KERNEL_BASE
0x80000000
so.... there is the issue. We're setting vaddr to start at 0x300000, but
the mmu_page checks for >= KERNEL_BASE (0x80000000)
--
Ticket URL: <https://dev.haiku-os.org/ticket/11896#comment:8>
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