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https://github.com/justinian/jsix.git
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Justin C. Miller
4ccaa2dfea
Remove ELF and initrd loading from the kernel. The bootloader now loads the initial programs, as it does with the kernel. Other files that were in the initrd are now on the ESP, and non-program files are just passed as modules.
98 lines
3.2 KiB
C++
98 lines
3.2 KiB
C++
/// \file memory.h
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/// Memory-related constants and functions.
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#pragma once
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#include <uefi/boot_services.h>
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#include <uefi/runtime_services.h>
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#include <stdint.h>
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#include "kernel_args.h"
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#include "pointer_manipulation.h"
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namespace boot {
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namespace memory {
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/// UEFI specifies that pages are always 4 KiB.
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constexpr size_t page_size = 0x1000;
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/// Get the number of pages needed to hold `bytes` bytes
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inline constexpr size_t bytes_to_pages(size_t bytes) {
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return ((bytes - 1) / page_size) + 1;
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}
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/// \defgroup memory_types
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/// Custom UEFI memory type values used for data being passed to the kernel
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/// @{
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/// Memory containing the kernel args structure
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constexpr uefi::memory_type args_type =
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static_cast<uefi::memory_type>(0x80000000);
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/// Memory containing any loaded modules to be passed to the kernel
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constexpr uefi::memory_type module_type =
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static_cast<uefi::memory_type>(0x80000001);
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/// Memory containing loaded kernel or program code and data sections
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constexpr uefi::memory_type program_type =
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static_cast<uefi::memory_type>(0x80000002);
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/// Memory containing page tables set up by the loader
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constexpr uefi::memory_type table_type =
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static_cast<uefi::memory_type>(0x80000003);
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/// @}
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/// \defgroup pointer_fixup
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/// Memory virtualization pointer fixup functions. Handles changing affected pointers
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/// when calling UEFI's `set_virtual_address_map` function to change the location of
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/// runtime services in virtual memory.
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/// @{
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/// Set up the pointer fixup UEFI events. This registers the necessary callbacks for
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/// runtime services to call when `set_virtual_address_map` is called.
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void init_pointer_fixup(uefi::boot_services *bs, uefi::runtime_services *rs);
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/// Mark a given pointer as needing to be updated when doing pointer fixup.
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void mark_pointer_fixup(void **p);
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/// @}
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/// Struct that represents UEFI's memory map. Contains a pointer to the map data
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/// as well as the data on how to read it.
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struct efi_mem_map
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{
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using desc = uefi::memory_descriptor;
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using iterator = offset_iterator<desc>;
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size_t length; ///< Total length of the map data
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size_t size; ///< Size of an entry in the array
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size_t key; ///< Key for detecting changes
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uint32_t version; ///< Version of the `memory_descriptor` struct
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desc *entries; ///< The array of UEFI descriptors
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efi_mem_map() : length(0), size(0), key(0), version(0), entries(nullptr) {}
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/// Get the count of entries in the array
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inline size_t num_entries() const { return length / size; }
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/// Return an iterator to the beginning of the array
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iterator begin() { return iterator(entries, size); }
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/// Return an iterator to the end of the array
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iterator end() { return offset_ptr<desc>(entries, length); }
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};
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/// Add the kernel's memory map as a module to the kernel args.
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/// \returns The uefi memory map used to build the kernel map
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efi_mem_map build_kernel_mem_map(kernel::args::header *args, uefi::boot_services *bs);
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/// Activate the given memory mappings. Sets the given page tables live as well
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/// as informs UEFI runtime services of the new mappings.
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/// \arg pml4 The root page table for the new mappings
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/// \arg map The UEFI memory map, used to update runtime services
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void virtualize(
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void *pml4,
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efi_mem_map &map,
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uefi::runtime_services *rs);
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} // namespace boot
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} // namespace memory
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