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| author | Felix Morgner <felix.morgner@ost.ch> | 2026-04-29 09:36:43 +0200 |
|---|---|---|
| committer | Felix Morgner <felix.morgner@ost.ch> | 2026-04-29 09:36:43 +0200 |
| commit | d6ef2153fb32ee7ba04acdf37e7a535a855229db (patch) | |
| tree | d2cd3275797208b1f78c44baa63739fa8645146f /arch/x86_64/src/boot/boot32.S | |
| parent | d906d70c94c2a40d5fc6fd26056c7bc57d540002 (diff) | |
| parent | c3d5a155025b445ab9213f131681afe9410b4e66 (diff) | |
| download | teachos-d6ef2153fb32ee7ba04acdf37e7a535a855229db.tar.xz teachos-d6ef2153fb32ee7ba04acdf37e7a535a855229db.zip | |
Merge branch 'fmorgner/develop-BA-FS26/x86-64-use-p1204-layout' into 'develop-BA-FS26'
chore: migrate 'arch' to p1204 project layout
See merge request teachos/kernel!28
Diffstat (limited to 'arch/x86_64/src/boot/boot32.S')
| -rw-r--r-- | arch/x86_64/src/boot/boot32.S | 443 |
1 files changed, 0 insertions, 443 deletions
diff --git a/arch/x86_64/src/boot/boot32.S b/arch/x86_64/src/boot/boot32.S deleted file mode 100644 index e6fcd85..0000000 --- a/arch/x86_64/src/boot/boot32.S +++ /dev/null @@ -1,443 +0,0 @@ -#include <arch/boot/boot.hpp> - -/** - * @brief Uninitialized data for the bootstrapping process. - */ -.section .boot_bss, "aw", @nobits - -page_maps_start: -page_map_level_4: .skip 512 * 8 -page_map_level_3_high: .skip 512 * 8 -page_map_level_3_low: .skip 512 * 8 -page_map_level_2: .skip 512 * 8 -page_maps_end = . -page_maps_size = page_maps_end - page_maps_start - -/** - * @brief Storage for the multiboot2 information pointer. - */ -.global multiboot_information_pointer -multiboot_information_pointer: .skip 8 - -/** - * @brief Storage for the bootstrap stack. - */ -.section .boot_stack, "aw", @nobits -.align 16 - -early_stack_bottom: .skip 1 << 8 -early_stack_top: -early_stack_size = early_stack_top - early_stack_bottom - -/** - * @brief Constants for the bootstrapping process. - */ -.section .boot_rodata, "a", @progbits - -.global global_descriptor_table_data - -/** - * @brief A basic GDT for long mode. - */ -global_descriptor_table: -global_descriptor_table_null = . - global_descriptor_table -.quad 0 -global_descriptor_table_code = . - global_descriptor_table -.quad GDT_READ_WRITE | GDT_EXECUTABLE | GDT_DESCRIPTOR_TYPE | GDT_PRESENT | GDT_LONG_MODE | (1 << 55) -global_descriptor_table_data = . - global_descriptor_table -.quad GDT_READ_WRITE | GDT_DESCRIPTOR_TYPE | GDT_PRESENT | (1 << 54) | (1 << 55) -global_descriptor_table_end: - -message_prefix_panic: .string "Panic: " -message_not_loaded_by_multiboot2: .string "The operating system was not loaded by a Multiboot 2 loader." -message_cpuid_instruction_no_supported: .string "The 'cpuid' instruction is not supported on this platform." -message_long_mode_not_supported: .string "Long mode is not supported by this platform." -message_return_from_kernel_main: .string "Execution returned from kernel main." - -/** - * @brief Initialized data for the bootstrapping process. - */ -.section .boot_data, "aw", @progbits - -/** - * @brief A pointer to the current position within the VGA text buffer. - */ -.global vga_buffer_pointer -vga_buffer_pointer: .quad 0xb8000 - -/** - * @brief Code for the bootstrapping process. - */ -.section .boot_text, "ax", @progbits -.align 16 -.code32 - -.macro pie_base - push %esi - call 0f - 0: - pop %esi -.endm - -.macro function_start - push %ebp - mov %esp, %ebp -.endm - -.macro function_end - leave - ret -.endm - -.macro pie_function_start - function_start - pie_base -.endm - -.macro pie_function_end - pop %esi - function_end -.endm - -/** - * @brief Prepare the environment and start the kernel. - * - * This function performs all necessary checks to ensure the system was loaded - * by the expected loader and supports all features required to run the kernel. - * If successful, it prepares the system by setting up memory virtualization - * and then start the kernel proper. - * - * @param %eax The Multiboot 2 magic marker. - * @param %ebx The Multiboot 2 information pointer. - * @return void This function does not return. - */ -.global _start -_start: - call 0f -0: - pop %esi - - lea (early_stack_top - 0b)(%esi), %ecx - - mov %ecx, %esp - mov %esp, %ebp - - call _assert_loaded_by_multiboot2_loader - call _save_multiboot_information_pointer - - call _assert_cpuid_instruction_is_supported - call _assert_cpu_supports_long_mode - - push $HUGE_PAGES_TO_MAP - call _prepare_page_maps - add $4, %esp - - call _enable_paging - call _enable_sse - call _reload_gdt - - lea (_entry64 - 0b)(%esi), %eax - pushl $global_descriptor_table_code - pushl %eax - lret - -/** - * @brief Halt the system. - * - * This function will instruct the CPU to halt. It will try to keep the CPU - * halted, even if interrupts occur. - * - * @return This function never returns. - */ -_halt: - function_start - -1: - hlt - jmp 1b - - function_end - -/** - * @brief Print a message via the VGA text buffer. - * - * @param ebp+12 The message to print. - * @param ebp+8 The color to print the message in. - */ -_print: - pie_function_start - - push %edi - push %ebx - - mov 8(%ebp), %al - mov 12(%ebp), %edx - mov $0, %ecx - lea (vga_buffer_pointer - 0b)(%esi), %edi - mov (%edi), %edi - -1: - mov (%edx, %ecx), %bl - test %bl, %bl - je 2f - mov %bl, (%edi, %ecx, 2) - mov %al, 1(%edi, %ecx, 2) - inc %ecx - jmp 1b - -2: - shl $1, %ecx - add %ecx, %edi - lea (vga_buffer_pointer - 0b)(%esi), %ecx - mov %edi, (%ecx) - - pop %ebx - pop %edi - - pie_function_end - -/** - * @brief Print a given panic message and then halt the machine as if by calling ::halt() - * - * @param ebp+4 A message to print. - * @return This function does not return. - */ -_panic: - pie_function_start - - lea (message_prefix_panic - 0b)(%esi), %eax - - push %eax - push $0x4f - call _print - - mov 8(%ebp), %eax - mov %eax, 4(%esp) - call _print - add $8, %esp - - call _halt - - pie_function_end - -/** - * Assert that we were loaded by a Multiboot 2 compliant bootloader. - * - * This assertion will panic the system if the magic signature was not found. - * If we were loaded my an appropriate bootloader, this function also saves - * the provided MBI pointer to `multiboot_information_pointer`. - */ -_assert_loaded_by_multiboot2_loader: - pie_function_start - - cmp $MULTIBOOT2_MAGIC, %eax - je 1f - lea (message_not_loaded_by_multiboot2 - 0b)(%esi), %eax - push %eax - call _panic -1: - pie_function_end - -/** - * @brief Store the multiboot 2 information pointer in the global memory. - * - * @return void - */ -_save_multiboot_information_pointer: - pie_function_start - - lea (multiboot_information_pointer - 0b)(%esi), %eax - mov %ebx, (%eax) - - pie_function_end - -/** - * @brief Assert that the CPU supports the CPUID instruction. - * - * The primary way to check for support of the instruction is to flip the ID - * bin in EFLAGS and then check if this changed was accepted. If so, the CPU - * supports the CPUID instruction, otherwise it most-likely doesn't. - */ -_assert_cpuid_instruction_is_supported: - pie_function_start - - pushfl - pop %eax - mov %eax, %ecx - - xor $(1 << 21), %eax /* Flip the ID bit */ - push %eax /* Move the new bitset on the stack for loading */ - popfl /* Load the flags with ID set back into EFLAGS */ - pushfl /* Copy the flags back onto the stack */ - pop %eax /* Load the flags for further checking */ - - push %ecx - popfl - - cmp %ecx, %eax - jne 1f - lea (message_cpuid_instruction_no_supported - 0b)(%esi), %eax - push %eax - call _panic - -1: - pie_function_end - -/** - * @brief Assert that the CPU supports going into long mode. - */ -_assert_cpu_supports_long_mode: - pie_function_start - - mov $0x80000000, %eax - cpuid - cmp $0x80000001, %eax - jb 1f - - mov $0x80000001, %eax - cpuid - test $(1 << 29), %edx - jnz 2f -1: - lea (message_long_mode_not_supported - 0b)(%esi), %eax - push %eax - call _panic -2: - pie_function_end - -/** - * @brief Prepare a basic page map hierarchy - * - * @param ebp+8 The number of huge pages to map - * @return void - */ -_prepare_page_maps: - pie_function_start - - push %edi - - call _clear_page_map_memory - - lea (page_map_level_4 - 0b)(%esi), %edi - lea (page_map_level_3_low - 0b)(%esi), %eax - or $0b11, %eax - mov %eax, (%edi) - - lea (page_map_level_3_high - 0b)(%esi), %eax - or $0b11, %eax - mov %eax, (511 * 8)(%edi) - - lea (page_map_level_3_low - 0b)(%esi), %edi - lea (page_map_level_2 - 0b)(%esi), %eax - or $0b11, %eax - mov %eax, (%edi) - - lea (page_map_level_3_high - 0b)(%esi), %edi - lea (page_map_level_2 - 0b)(%esi), %eax - or $0b11, %eax - mov %eax, (510 * 8)(%edi) - - lea (page_map_level_2 - 0b)(%esi), %edi - mov 8(%ebp), %ecx - -1: - dec %ecx - mov $(1 << 21), %eax - mul %ecx - or $0b10000011, %eax - mov %eax, (%edi, %ecx, 8) - - test %ecx, %ecx - jnz 1b - - pop %edi - - pie_function_end - -/** - * @brief Clear all page map memory by filling it with 0s. - * - * @return void - */ -_clear_page_map_memory: - pie_function_start - - push %edi - - xor %eax, %eax - mov $page_maps_size, %ecx - shr $2, %ecx - lea (page_maps_start - 0b)(%esi), %edi - rep stosl - - pop %edi - - pie_function_end - -/** - * @p Enable memory virtualization via paging. - * - * Note: This routine expects for there to be a valid set of page maps already - * set up for use. - * - * @return void - */ -_enable_paging: - pie_function_start - - lea (page_map_level_4 - 0b)(%esi), %eax - mov %eax, %cr3 - - /* Enable Physical Address Extension */ - mov %cr4, %eax - or $(1 << 5), %eax - mov %eax, %cr4 - - /* Enable long mode support */ - mov $0xC0000080, %ecx - rdmsr - or $(1 << 8), %eax - wrmsr - - /* Enable paging */ - mov %cr0, %eax - or $(1 << 31), %eax - mov %eax, %cr0 - - pie_function_end - -/** - * @brief Enable use of SSE instructions. - */ -_enable_sse: - function_start - - mov %cr0, %eax - and $0xfffffffb, %eax - or $0x00000002, %eax - mov %eax, %cr0 - - mov %cr4, %eax - or $(3 << 9), %eax - mov %eax, %cr4 - - function_end - -/** - * @brief Prepare a new GTD and load make it active. - * - * @return void - */ -_reload_gdt: - pie_function_start - - sub $10, %esp - lea (global_descriptor_table - 0b)(%esi), %eax - movw $(global_descriptor_table_end - global_descriptor_table -1), (%esp) - mov %eax, 2(%esp) - movl $0, 6(%esp) - - lgdt (%esp) - add $10, %esp - - pie_function_end |
