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Fix mis-flagged page table entries

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This commit is contained in:
Justin C. Miller
2019-07-04 17:43:08 -07:00
parent 3a68ec439d
commit c3dacb2906
2 changed files with 34 additions and 7 deletions
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28
src/kernel/memory_bootstrap.cpp
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@@ -186,9 +186,31 @@ memory_initialize(uint16_t scratch_pages, const void *memory_map, size_t map_len
page_table *id_pml4 = &tables[0];
page_table *id_pdp = &tables[1];
// Flags: 0 0 0 0 1 1 0 0 0 0 0 1 1 = 0x0183
// | IGN | | | | | | | | +- Present
// | | | | | | | | +--- Writeable
// | | | | | | | +----- Supervisor only
// | | | | | | +------- PWT (determining memory type for page)
// | | | | | +---------- PCD (determining memory type for page)
// | | | | +------------ Accessed flag (not accessed yet)
// | | | +-------------- Dirty (not dirtied yet)
// | | +---------------- Page size (1GiB page)
// | +------------------- Global
// +---------------------------- PAT (determining memory type for page)
for (int i=0; i<512; ++i)
id_pdp->entries[i] = (static_cast<uintptr_t>(i) << 30) | 0x18b;
id_pml4->entries[511] = reinterpret_cast<uintptr_t>(id_pdp) | 0x10b;
id_pdp->entries[i] = (static_cast<uintptr_t>(i) << 30) | 0x0183;
// Flags: 0 0 0 0 0 0 0 0 0 0 1 1 = 0x0003
// IGNORED | | | | | | | +- Present
// | | | | | | +--- Writeable
// | | | | | +----- Supervisor only
// | | | | +------- PWT (determining memory type for pdpt)
// | | | +---------- PCD (determining memory type for pdpt)
// | | +------------ Accessed flag (not accessed yet)
// | +-------------- Ignored
// +---------------- Reserved 0
id_pml4->entries[511] = reinterpret_cast<uintptr_t>(id_pdp) | 0x003;
// Make sure the page table is finished updating before we write to memory
__sync_synchronize();
@@ -218,7 +240,7 @@ memory_initialize(uint16_t scratch_pages, const void *memory_map, size_t map_len
pml4 = kutil::offset_pointer(pml4, page_offset);
kutil::memset(pml4, 0, sizeof(page_table));
pml4->entries[511] = reinterpret_cast<uintptr_t>(id_pdp) | 0x10b;
pml4->entries[511] = reinterpret_cast<uintptr_t>(id_pdp) | 0x003;
bootstrap.page_in_kernel(*pm, pml4);