cregit-Linux how code gets into the kernel

Release 4.7 drivers/firmware/efi/libstub/fdt.c

/*
 * FDT related Helper functions used by the EFI stub on multiple
 * architectures. This should be #included by the EFI stub
 * implementation files.
 *
 * Copyright 2013 Linaro Limited; author Roy Franz
 *
 * This file is part of the Linux kernel, and is made available
 * under the terms of the GNU General Public License version 2.
 *
 */

#include <linux/efi.h>
#include <linux/libfdt.h>
#include <asm/efi.h>

#include "efistub.h"


efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, unsigned long orig_fdt_size, void *fdt, int new_fdt_size, char *cmdline_ptr, u64 initrd_addr, u64 initrd_size, efi_memory_desc_t *memory_map, unsigned long map_size, unsigned long desc_size, u32 desc_ver) { int node, num_rsv; int status; u32 fdt_val32; u64 fdt_val64; /* Do some checks on provided FDT, if it exists*/ if (orig_fdt) { if (fdt_check_header(orig_fdt)) { pr_efi_err(sys_table, "Device Tree header not valid!\n"); return EFI_LOAD_ERROR; } /* * We don't get the size of the FDT if we get if from a * configuration table. */ if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) { pr_efi_err(sys_table, "Truncated device tree! foo!\n"); return EFI_LOAD_ERROR; } } if (orig_fdt) status = fdt_open_into(orig_fdt, fdt, new_fdt_size); else status = fdt_create_empty_tree(fdt, new_fdt_size); if (status != 0) goto fdt_set_fail; /* * Delete all memory reserve map entries. When booting via UEFI, * kernel will use the UEFI memory map to find reserved regions. */ num_rsv = fdt_num_mem_rsv(fdt); while (num_rsv-- > 0) fdt_del_mem_rsv(fdt, num_rsv); node = fdt_subnode_offset(fdt, 0, "chosen"); if (node < 0) { node = fdt_add_subnode(fdt, 0, "chosen"); if (node < 0) { status = node; /* node is error code when negative */ goto fdt_set_fail; } } if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) { status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr, strlen(cmdline_ptr) + 1); if (status) goto fdt_set_fail; } /* Set initrd address/end in device tree, if present */ if (initrd_size != 0) { u64 initrd_image_end; u64 initrd_image_start = cpu_to_fdt64(initrd_addr); status = fdt_setprop(fdt, node, "linux,initrd-start", &initrd_image_start, sizeof(u64)); if (status) goto fdt_set_fail; initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); status = fdt_setprop(fdt, node, "linux,initrd-end", &initrd_image_end, sizeof(u64)); if (status) goto fdt_set_fail; } /* Add FDT entries for EFI runtime services in chosen node. */ node = fdt_subnode_offset(fdt, 0, "chosen"); fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table); status = fdt_setprop(fdt, node, "linux,uefi-system-table", &fdt_val64, sizeof(fdt_val64)); if (status) goto fdt_set_fail; fdt_val64 = cpu_to_fdt64((u64)(unsigned long)memory_map); status = fdt_setprop(fdt, node, "linux,uefi-mmap-start", &fdt_val64, sizeof(fdt_val64)); if (status) goto fdt_set_fail; fdt_val32 = cpu_to_fdt32(map_size); status = fdt_setprop(fdt, node, "linux,uefi-mmap-size", &fdt_val32, sizeof(fdt_val32)); if (status) goto fdt_set_fail; fdt_val32 = cpu_to_fdt32(desc_size); status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size", &fdt_val32, sizeof(fdt_val32)); if (status) goto fdt_set_fail; fdt_val32 = cpu_to_fdt32(desc_ver); status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver", &fdt_val32, sizeof(fdt_val32)); if (status) goto fdt_set_fail; if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { efi_status_t efi_status; efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64), (u8 *)&fdt_val64); if (efi_status == EFI_SUCCESS) { status = fdt_setprop(fdt, node, "kaslr-seed", &fdt_val64, sizeof(fdt_val64)); if (status) goto fdt_set_fail; } else if (efi_status != EFI_NOT_FOUND) { return efi_status; } } return EFI_SUCCESS; fdt_set_fail: if (status == -FDT_ERR_NOSPACE) return EFI_BUFFER_TOO_SMALL; return EFI_LOAD_ERROR; }

Contributors

PersonTokensPropCommitsCommitProp
roy franzroy franz52884.08%133.33%
ard biesheuvelard biesheuvel7712.26%133.33%
mark saltermark salter233.66%133.33%
Total628100.00%3100.00%

#ifndef EFI_FDT_ALIGN #define EFI_FDT_ALIGN EFI_PAGE_SIZE #endif /* * Allocate memory for a new FDT, then add EFI, commandline, and * initrd related fields to the FDT. This routine increases the * FDT allocation size until the allocated memory is large * enough. EFI allocations are in EFI_PAGE_SIZE granules, * which are fixed at 4K bytes, so in most cases the first * allocation should succeed. * EFI boot services are exited at the end of this function. * There must be no allocations between the get_memory_map() * call and the exit_boot_services() call, so the exiting of * boot services is very tightly tied to the creation of the FDT * with the final memory map in it. */
efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, void *handle, unsigned long *new_fdt_addr, unsigned long max_addr, u64 initrd_addr, u64 initrd_size, char *cmdline_ptr, unsigned long fdt_addr, unsigned long fdt_size) { unsigned long map_size, desc_size; u32 desc_ver; unsigned long mmap_key; efi_memory_desc_t *memory_map, *runtime_map; unsigned long new_fdt_size; efi_status_t status; int runtime_entry_count = 0; /* * Get a copy of the current memory map that we will use to prepare * the input for SetVirtualAddressMap(). We don't have to worry about * subsequent allocations adding entries, since they could not affect * the number of EFI_MEMORY_RUNTIME regions. */ status = efi_get_memory_map(sys_table, &runtime_map, &map_size, &desc_size, &desc_ver, &mmap_key); if (status != EFI_SUCCESS) { pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n"); return status; } pr_efi(sys_table, "Exiting boot services and installing virtual address map...\n"); /* * Estimate size of new FDT, and allocate memory for it. We * will allocate a bigger buffer if this ends up being too * small, so a rough guess is OK here. */ new_fdt_size = fdt_size + EFI_PAGE_SIZE; while (1) { status = efi_high_alloc(sys_table, new_fdt_size, EFI_FDT_ALIGN, new_fdt_addr, max_addr); if (status != EFI_SUCCESS) { pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n"); goto fail; } /* * Now that we have done our final memory allocation (and free) * we can get the memory map key needed for * exit_boot_services(). */ status = efi_get_memory_map(sys_table, &memory_map, &map_size, &desc_size, &desc_ver, &mmap_key); if (status != EFI_SUCCESS) goto fail_free_new_fdt; status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, (void *)*new_fdt_addr, new_fdt_size, cmdline_ptr, initrd_addr, initrd_size, memory_map, map_size, desc_size, desc_ver); /* Succeeding the first time is the expected case. */ if (status == EFI_SUCCESS) break; if (status == EFI_BUFFER_TOO_SMALL) { /* * We need to allocate more space for the new * device tree, so free existing buffer that is * too small. Also free memory map, as we will need * to get new one that reflects the free/alloc we do * on the device tree buffer. */ efi_free(sys_table, new_fdt_size, *new_fdt_addr); sys_table->boottime->free_pool(memory_map); new_fdt_size += EFI_PAGE_SIZE; } else { pr_efi_err(sys_table, "Unable to construct new device tree.\n"); goto fail_free_mmap; } } /* * Update the memory map with virtual addresses. The function will also * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME * entries so that we can pass it straight into SetVirtualAddressMap() */ efi_get_virtmap(memory_map, map_size, desc_size, runtime_map, &runtime_entry_count); /* Now we are ready to exit_boot_services.*/ status = sys_table->boottime->exit_boot_services(handle, mmap_key); if (status == EFI_SUCCESS) { efi_set_virtual_address_map_t *svam; /* Install the new virtual address map */ svam = sys_table->runtime->set_virtual_address_map; status = svam(runtime_entry_count * desc_size, desc_size, desc_ver, runtime_map); /* * We are beyond the point of no return here, so if the call to * SetVirtualAddressMap() failed, we need to signal that to the * incoming kernel but proceed normally otherwise. */ if (status != EFI_SUCCESS) { int l; /* * Set the virtual address field of all * EFI_MEMORY_RUNTIME entries to 0. This will signal * the incoming kernel that no virtual translation has * been installed. */ for (l = 0; l < map_size; l += desc_size) { efi_memory_desc_t *p = (void *)memory_map + l; if (p->attribute & EFI_MEMORY_RUNTIME) p->virt_addr = 0; } } return EFI_SUCCESS; } pr_efi_err(sys_table, "Exit boot services failed.\n"); fail_free_mmap: sys_table->boottime->free_pool(memory_map); fail_free_new_fdt: efi_free(sys_table, new_fdt_size, *new_fdt_addr); fail: sys_table->boottime->free_pool(runtime_map); return EFI_LOAD_ERROR; }

Contributors

PersonTokensPropCommitsCommitProp
roy franzroy franz28963.38%133.33%
ard biesheuvelard biesheuvel16636.40%133.33%
masanari iidamasanari iida10.22%133.33%
Total456100.00%3100.00%


void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) { efi_guid_t fdt_guid = DEVICE_TREE_GUID; efi_config_table_t *tables; void *fdt; int i; tables = (efi_config_table_t *) sys_table->tables; fdt = NULL; for (i = 0; i < sys_table->nr_tables; i++) if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) { fdt = (void *) tables[i].table; if (fdt_check_header(fdt) != 0) { pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); return NULL; } *fdt_size = fdt_totalsize(fdt); break; } return fdt; }

Contributors

PersonTokensPropCommitsCommitProp
roy franzroy franz9072.58%150.00%
ard biesheuvelard biesheuvel3427.42%150.00%
Total124100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
roy franzroy franz91874.57%114.29%
ard biesheuvelard biesheuvel28923.48%457.14%
mark saltermark salter231.87%114.29%
masanari iidamasanari iida10.08%114.29%
Total1231100.00%7100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}