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Kernel: Map multiboot2 memory in PageTable initialization 

It cannot be assumed that multiboot data lies between kernel_end
and 2 GiB mark, so I properly allocate virtual address space for it.
This commit is contained in:
Bananymous 2023-10-17 01:15:08 +03:00
parent be3efb0b92
commit e2e5c31d54
2 changed files with 16 additions and 12 deletions
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26
kernel/arch/x86_64/PageTable.cpp
View File

@ -138,16 +138,6 @@ namespace Kernel
// Map (0 -> phys_kernel_end) to (KERNEL_OFFSET -> virt_kernel_end)
map_range_at(0, KERNEL_OFFSET, (uintptr_t)g_kernel_end - KERNEL_OFFSET, Flags::ReadWrite | Flags::Present);
// Map multiboot info
vaddr_t multiboot_data_start = (vaddr_t)g_multiboot2_info & PAGE_ADDR_MASK;
vaddr_t multiboot_data_end = (vaddr_t)g_multiboot2_info + g_multiboot2_info->total_size;
map_range_at(
V2P(multiboot_data_start),
multiboot_data_start,
multiboot_data_end - multiboot_data_start,
Flags::ReadWrite | Flags::Present
);
// Map executable kernel memory as executable
map_range_at(
@ -164,6 +154,22 @@ namespace Kernel
g_userspace_end - g_userspace_start,
Flags::Execute | Flags::UserSupervisor | Flags::Present
);
// Map multiboot memory
paddr_t multiboot2_data_start = (vaddr_t)g_multiboot2_info & PAGE_ADDR_MASK;
paddr_t multiboot2_data_end = (vaddr_t)g_multiboot2_info + g_multiboot2_info->total_size;
size_t multiboot2_needed_pages = BAN::Math::div_round_up<size_t>(multiboot2_data_end - multiboot2_data_start, PAGE_SIZE);
vaddr_t multiboot2_vaddr = reserve_free_contiguous_pages(multiboot2_needed_pages, KERNEL_OFFSET);
map_range_at(
multiboot2_data_start,
multiboot2_vaddr,
multiboot2_needed_pages * PAGE_SIZE,
Flags::ReadWrite | Flags::Present
);
g_multiboot2_info = (multiboot2_info_t*)(multiboot2_vaddr + ((vaddr_t)g_multiboot2_info % PAGE_SIZE));
}
BAN::ErrorOr<PageTable*> PageTable::create_userspace()

2
kernel/arch/x86_64/boot.S
View File

@ -197,8 +197,6 @@ long_mode:
jmp *%rcx
higher_half:
addq $KERNEL_OFFSET, g_multiboot2_info
# call global constuctors
call _init