1 /* 2 * Copyright 2019-2022 Haiku, Inc. All rights reserved. 3 * Released under the terms of the MIT License. 4 */ 5 6 7 #include <boot/platform.h> 8 #include <boot/stage2.h> 9 #include <boot/stdio.h> 10 11 #include "efi_platform.h" 12 13 #include "aarch64.h" 14 15 extern "C" void arch_enter_kernel(struct kernel_args *kernelArgs, 16 addr_t kernelEntry, addr_t kernelStackTop); 17 18 extern void arch_mmu_dump_present_tables(); 19 extern const char* granule_type_str(int tg); 20 21 extern uint32_t arch_mmu_generate_post_efi_page_tables(size_t memory_map_size, 22 efi_memory_descriptor *memory_map, size_t descriptor_size, 23 uint32_t descriptor_version); 24 25 extern void arch_mmu_post_efi_setup(size_t memory_map_size, 26 efi_memory_descriptor *memory_map, size_t descriptor_size, 27 uint32_t descriptor_version); 28 29 extern void arch_mmu_setup_EL1(); 30 31 32 static const char* 33 memory_region_type_str(int type) 34 { 35 switch (type) { 36 case EfiReservedMemoryType: 37 return "ReservedMemoryType"; 38 case EfiLoaderCode: 39 return "LoaderCode"; 40 case EfiLoaderData: 41 return "LoaderData"; 42 case EfiBootServicesCode: 43 return "BootServicesCode"; 44 case EfiBootServicesData: 45 return "BootServicesData"; 46 case EfiRuntimeServicesCode: 47 return "RuntimeServicesCode"; 48 case EfiRuntimeServicesData: 49 return "RuntimeServicesData"; 50 case EfiConventionalMemory: 51 return "ConventionalMemory"; 52 case EfiUnusableMemory: 53 return "UnusableMemory"; 54 case EfiACPIReclaimMemory: 55 return "ACPIReclaimMemory"; 56 case EfiACPIMemoryNVS: 57 return "ACPIMemoryNVS"; 58 case EfiMemoryMappedIO: 59 return "MMIO"; 60 case EfiMemoryMappedIOPortSpace: 61 return "MMIOPortSpace"; 62 case EfiPalCode: 63 return "PalCode"; 64 case EfiPersistentMemory: 65 return "PersistentMemory"; 66 default: 67 return "unknown"; 68 } 69 } 70 71 72 void 73 arch_convert_kernel_args(void) 74 { 75 // empty 76 } 77 78 79 void 80 arch_start_kernel(addr_t kernelEntry) 81 { 82 // Prepare to exit EFI boot services. 83 // Read the memory map. 84 // First call is to determine the buffer size. 85 size_t memory_map_size = 0; 86 efi_memory_descriptor dummy; 87 efi_memory_descriptor *memory_map; 88 size_t map_key; 89 size_t descriptor_size; 90 uint32_t descriptor_version; 91 if (kBootServices->GetMemoryMap(&memory_map_size, &dummy, &map_key, 92 &descriptor_size, &descriptor_version) != EFI_BUFFER_TOO_SMALL) { 93 panic("Unable to determine size of system memory map"); 94 } 95 96 // Allocate a buffer twice as large as needed just in case it gets bigger 97 // between calls to ExitBootServices. 98 size_t actual_memory_map_size = memory_map_size * 2; 99 memory_map 100 = (efi_memory_descriptor *)kernel_args_malloc(actual_memory_map_size); 101 102 if (memory_map == NULL) 103 panic("Unable to allocate memory map."); 104 105 // Read (and print) the memory map. 106 memory_map_size = actual_memory_map_size; 107 if (kBootServices->GetMemoryMap(&memory_map_size, memory_map, &map_key, 108 &descriptor_size, &descriptor_version) != EFI_SUCCESS) { 109 panic("Unable to fetch system memory map."); 110 } 111 112 addr_t addr = (addr_t)memory_map; 113 efi_physical_addr loaderCode = 0LL; 114 dprintf("System provided memory map:\n"); 115 for (size_t i = 0; i < memory_map_size / descriptor_size; ++i) { 116 efi_memory_descriptor *entry 117 = (efi_memory_descriptor *)(addr + i * descriptor_size); 118 dprintf(" phys: 0x%0lx-0x%0lx, virt: 0x%0lx-0x%0lx, size = 0x%0lx, type: %s (%#x), attr: %#lx\n", 119 entry->PhysicalStart, 120 entry->PhysicalStart + entry->NumberOfPages * B_PAGE_SIZE, 121 entry->VirtualStart, 122 entry->VirtualStart + entry->NumberOfPages * B_PAGE_SIZE, 123 entry->NumberOfPages * B_PAGE_SIZE, 124 memory_region_type_str(entry->Type), entry->Type, 125 entry->Attribute); 126 if (entry->Type == EfiLoaderCode) 127 loaderCode = entry->PhysicalStart; 128 } 129 // This is where our efi loader got relocated, therefore we need to use this 130 // offset for properly align symbols 131 dprintf("Efi loader symbols offset: 0x%0lx:\n", loaderCode); 132 133 // Generate page tables for use after ExitBootServices. 134 arch_mmu_generate_post_efi_page_tables( 135 memory_map_size, memory_map, descriptor_size, descriptor_version); 136 137 bool el2toel1 = false; 138 /* 139 * "The AArch64 exception model is made up of a number of exception levels 140 * (EL0 - EL3), with EL0 and EL1 having a secure and a non-secure 141 * counterpart. EL2 is the hypervisor level and exists only in non-secure 142 * mode. EL3 is the highest priority level and exists only in secure mode." 143 * 144 * "2.3 UEFI System Environment and Configuration 145 * The resident UEFI boot-time environment shall use the highest non-secure 146 * privilege level available. The exact meaning of this is architecture 147 * dependent, as detailed below." 148 149 * "2.3.1 AArch64 Exception Levels 150 * On AArch64 UEFI shall execute as 64-bit code at either EL1 or EL2, 151 * depending on whether or not virtualization is available at OS load time." 152 */ 153 if (arch_exception_level() != 1) { 154 dprintf("Current Exception Level EL%1ld\n", arch_exception_level()); 155 if (arch_exception_level() == 2) { 156 /* Transitioning from EL we lose present MMU configuration 157 * which we would like to preserve e.g. peripherals mappings */ 158 if (arch_mmu_enabled()) { 159 dprintf("MMU Enabled, Translation Table @ %lx Granularity %s, bits %d\n", 160 arch_mmu_base_register(), 161 granule_type_str(arch_mmu_user_granule()), 162 arch_mmu_user_address_bits()); 163 164 dprintf("Kernel entry accessibility W: %x R: %x\n", 165 arch_mmu_write_access(kernelEntry), 166 arch_mmu_read_access(kernelEntry)); 167 168 arch_mmu_dump_present_tables(); 169 170 el2toel1 = true; // we want to print before exit services 171 } 172 173 } else { 174 // Not ready, undexpected any transition different than EL2 >> EL1 175 panic("Unexpected Exception Level\n"); 176 } 177 } 178 179 180 // Attempt to fetch the memory map and exit boot services. 181 // This needs to be done in a loop, as ExitBootServices can change the 182 // memory map. 183 // Even better: Only GetMemoryMap and ExitBootServices can be called after 184 // the first call to ExitBootServices, as the firmware is permitted to 185 // partially exit. This is why twice as much space was allocated for the 186 // memory map, as it's impossible to allocate more now. 187 // A changing memory map shouldn't affect the generated page tables, as 188 // they only needed to know about the maximum address, not any specific 189 // entry. 190 dprintf("Calling ExitBootServices. So long, EFI!\n"); 191 while (true) { 192 if (kBootServices->ExitBootServices(kImage, map_key) == EFI_SUCCESS) { 193 // The console was provided by boot services, disable it. 194 stdout = NULL; 195 stderr = NULL; 196 // Can we adjust gKernelArgs.platform_args.serial_base_ports[0] 197 // to something fixed in qemu for debugging? 198 break; 199 } 200 201 memory_map_size = actual_memory_map_size; 202 if (kBootServices->GetMemoryMap(&memory_map_size, memory_map, &map_key, 203 &descriptor_size, &descriptor_version) != EFI_SUCCESS) { 204 panic("Unable to fetch system memory map."); 205 } 206 } 207 208 // Update EFI, generate final kernel physical memory map, etc. 209 //arch_mmu_post_efi_setup(memory_map_size, memory_map, 210 // descriptor_size, descriptor_version); 211 212 if (el2toel1) { 213 arch_mmu_setup_EL1(); 214 arch_cache_disable(); 215 216 _arch_transition_EL2_EL1(); 217 218 arch_cache_enable(); 219 } 220 221 //smp_boot_other_cpus(final_pml4, kernelEntry); 222 223 if (arch_mmu_read_access(kernelEntry) && arch_mmu_read_access(gKernelArgs.cpu_kstack[0].start)) { 224 // Enter the kernel! 225 arch_enter_kernel(&gKernelArgs, kernelEntry, 226 gKernelArgs.cpu_kstack[0].start + gKernelArgs.cpu_kstack[0].size - 8); 227 } else { 228 _arch_exception_panic("Kernel or Stack memory not accessible\n", __LINE__); 229 } 230 } 231