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 #include "mmu.h" 13 #include "serial.h" 14 15 #include "aarch64.h" 16 17 extern "C" void arch_enter_kernel( 18 struct kernel_args* kernelArgs, addr_t kernelEntry, addr_t kernelStackTop); 19 20 extern void arch_mmu_dump_present_tables(); 21 extern const char* granule_type_str(int tg); 22 23 extern uint32_t arch_mmu_generate_post_efi_page_tables(size_t memory_map_size, 24 efi_memory_descriptor* memory_map, size_t descriptor_size, uint32_t descriptor_version); 25 26 extern void arch_mmu_post_efi_setup(size_t memory_map_size, efi_memory_descriptor* memory_map, 27 size_t descriptor_size, uint32_t descriptor_version); 28 29 extern void arch_mmu_setup_EL1(uint64 tcr); 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 fix_address(gKernelArgs.arch_args.fdt); 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( 92 &memory_map_size, &dummy, &map_key, &descriptor_size, &descriptor_version) 93 != EFI_BUFFER_TOO_SMALL) { 94 panic("Unable to determine size of system memory map"); 95 } 96 97 // Allocate a buffer twice as large as needed just in case it gets bigger 98 // between calls to ExitBootServices. 99 size_t actual_memory_map_size = memory_map_size * 2; 100 memory_map = (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( 108 &memory_map_size, memory_map, &map_key, &descriptor_size, &descriptor_version) 109 != EFI_SUCCESS) { 110 panic("Unable to fetch system memory map."); 111 } 112 113 addr_t addr = (addr_t) memory_map; 114 efi_physical_addr loaderCode = 0LL; 115 dprintf("System provided memory map:\n"); 116 for (size_t i = 0; i < memory_map_size / descriptor_size; ++i) { 117 efi_memory_descriptor* entry = (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: " 119 "%#lx\n", 120 entry->PhysicalStart, entry->PhysicalStart + entry->NumberOfPages * B_PAGE_SIZE, 121 entry->VirtualStart, entry->VirtualStart + entry->NumberOfPages * B_PAGE_SIZE, 122 entry->NumberOfPages * B_PAGE_SIZE, memory_region_type_str(entry->Type), entry->Type, 123 entry->Attribute); 124 if (entry->Type == EfiLoaderCode) 125 loaderCode = entry->PhysicalStart; 126 } 127 // This is where our efi loader got relocated, therefore we need to use this 128 // offset for properly align symbols 129 dprintf("Efi loader symbols offset: 0x%0lx:\n", loaderCode); 130 131 /* 132 * "The AArch64 exception model is made up of a number of exception levels 133 * (EL0 - EL3), with EL0 and EL1 having a secure and a non-secure 134 * counterpart. EL2 is the hypervisor level and exists only in non-secure 135 * mode. EL3 is the highest priority level and exists only in secure mode." 136 * 137 * "2.3 UEFI System Environment and Configuration 138 * The resident UEFI boot-time environment shall use the highest non-secure 139 * privilege level available. The exact meaning of this is architecture 140 * dependent, as detailed below." 141 142 * "2.3.1 AArch64 Exception Levels 143 * On AArch64 UEFI shall execute as 64-bit code at either EL1 or EL2, 144 * depending on whether or not virtualization is available at OS load time." 145 */ 146 uint64 el = arch_exception_level(); 147 dprintf("Current Exception Level EL%1lx\n", el); 148 dprintf("TTBR0: %" B_PRIx64 " TTBRx: %" B_PRIx64 " SCTLR: %" B_PRIx64 " TCR: %" B_PRIx64 "\n", 149 arch_mmu_base_register(), arch_mmu_base_register(true), _arch_mmu_get_sctlr(), 150 _arch_mmu_get_tcr()); 151 152 if (arch_mmu_enabled()) { 153 dprintf("MMU Enabled, Granularity %s, bits %d\n", granule_type_str(arch_mmu_user_granule()), 154 arch_mmu_user_address_bits()); 155 156 dprintf("Kernel entry accessibility W: %x R: %x\n", arch_mmu_write_access(kernelEntry), 157 arch_mmu_read_access(kernelEntry)); 158 159 arch_mmu_dump_present_tables(); 160 161 if (el == 1) { 162 // Disable CACHE & MMU before dealing with TTBRx 163 arch_cache_disable(); 164 } 165 } 166 167 // Generate page tables for use after ExitBootServices. 168 arch_mmu_generate_post_efi_page_tables( 169 memory_map_size, memory_map, descriptor_size, descriptor_version); 170 171 // Attempt to fetch the memory map and exit boot services. 172 // This needs to be done in a loop, as ExitBootServices can change the 173 // memory map. 174 // Even better: Only GetMemoryMap and ExitBootServices can be called after 175 // the first call to ExitBootServices, as the firmware is permitted to 176 // partially exit. This is why twice as much space was allocated for the 177 // memory map, as it's impossible to allocate more now. 178 // A changing memory map shouldn't affect the generated page tables, as 179 // they only needed to know about the maximum address, not any specific 180 // entry. 181 dprintf("Calling ExitBootServices. So long, EFI!\n"); 182 while (true) { 183 if (kBootServices->ExitBootServices(kImage, map_key) == EFI_SUCCESS) { 184 // The console was provided by boot services, disable it. 185 stdout = NULL; 186 stderr = NULL; 187 // Can we adjust gKernelArgs.platform_args.serial_base_ports[0] 188 // to something fixed in qemu for debugging? 189 serial_switch_to_legacy(); 190 dprintf("Switched to legacy serial output\n"); 191 break; 192 } 193 194 memory_map_size = actual_memory_map_size; 195 if (kBootServices->GetMemoryMap( 196 &memory_map_size, memory_map, &map_key, &descriptor_size, &descriptor_version) 197 != EFI_SUCCESS) { 198 panic("Unable to fetch system memory map."); 199 } 200 } 201 202 // Update EFI, generate final kernel physical memory map, etc. 203 arch_mmu_post_efi_setup(memory_map_size, memory_map, descriptor_size, descriptor_version); 204 205 switch (el) { 206 case 1: 207 arch_mmu_setup_EL1(READ_SPECIALREG(TCR_EL1)); 208 break; 209 case 2: 210 arch_mmu_setup_EL1(READ_SPECIALREG(TCR_EL2)); 211 arch_cache_disable(); 212 _arch_transition_EL2_EL1(); 213 break; 214 default: 215 panic("Unexpected Exception Level\n"); 216 break; 217 } 218 219 arch_cache_enable(); 220 221 // smp_boot_other_cpus(final_pml4, kernelEntry, (addr_t)&gKernelArgs); 222 223 if (arch_mmu_read_access(kernelEntry) 224 && arch_mmu_read_access(gKernelArgs.cpu_kstack[0].start)) { 225 // Enter the kernel! 226 arch_enter_kernel(&gKernelArgs, kernelEntry, 227 gKernelArgs.cpu_kstack[0].start + gKernelArgs.cpu_kstack[0].size); 228 } else { 229 // _arch_exception_panic("Kernel or Stack memory not accessible\n", __LINE__); 230 panic("Kernel or Stack memory not accessible\n"); 231 } 232 } 233