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authorFelix Morgner <felix.morgner@ost.ch>2026-04-29 09:36:43 +0200
committerFelix Morgner <felix.morgner@ost.ch>2026-04-29 09:36:43 +0200
commitd6ef2153fb32ee7ba04acdf37e7a535a855229db (patch)
treed2cd3275797208b1f78c44baa63739fa8645146f /arch/x86_64/src/boot/boot32.S
parentd906d70c94c2a40d5fc6fd26056c7bc57d540002 (diff)
parentc3d5a155025b445ab9213f131681afe9410b4e66 (diff)
downloadteachos-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.S443
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