1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
10 static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
12 struct efi_arm_entry_state *efi_entry_state;
14 static void get_cpu_state(u32 *cpsr, u32 *sctlr)
16 asm("mrs %0, cpsr" : "=r"(*cpsr));
17 if ((*cpsr & MODE_MASK) == HYP_MODE)
18 asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
20 asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
23 efi_status_t check_platform_features(void)
29 get_cpu_state(&cpsr, &sctlr);
31 efi_info("Entering in %s mode with MMU %sabled\n",
32 ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
33 (sctlr & 1) ? "en" : "dis");
35 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
36 sizeof(*efi_entry_state),
37 (void **)&efi_entry_state);
38 if (status != EFI_SUCCESS) {
39 efi_err("allocate_pool() failed\n");
43 efi_entry_state->cpsr_before_ebs = cpsr;
44 efi_entry_state->sctlr_before_ebs = sctlr;
46 status = efi_bs_call(install_configuration_table, &cpu_state_guid,
48 if (status != EFI_SUCCESS) {
49 efi_err("install_configuration_table() failed\n");
53 /* non-LPAE kernels can run anywhere */
54 if (!IS_ENABLED(CONFIG_ARM_LPAE))
57 /* LPAE kernels need compatible hardware */
58 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
60 efi_err("This LPAE kernel is not supported by your CPU\n");
61 status = EFI_UNSUPPORTED;
67 efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
69 efi_bs_call(free_pool, efi_entry_state);
73 void efi_handle_post_ebs_state(void)
75 get_cpu_state(&efi_entry_state->cpsr_after_ebs,
76 &efi_entry_state->sctlr_after_ebs);
79 static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
81 struct screen_info *alloc_screen_info(void)
83 struct screen_info *si;
87 * Unlike on arm64, where we can directly fill out the screen_info
88 * structure from the stub, we need to allocate a buffer to hold
89 * its contents while we hand over to the kernel proper from the
92 status = efi_bs_call(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
93 sizeof(*si), (void **)&si);
95 if (status != EFI_SUCCESS)
98 status = efi_bs_call(install_configuration_table,
99 &screen_info_guid, si);
100 if (status == EFI_SUCCESS)
103 efi_bs_call(free_pool, si);
107 void free_screen_info(struct screen_info *si)
112 efi_bs_call(install_configuration_table, &screen_info_guid, NULL);
113 efi_bs_call(free_pool, si);
116 efi_status_t handle_kernel_image(unsigned long *image_addr,
117 unsigned long *image_size,
118 unsigned long *reserve_addr,
119 unsigned long *reserve_size,
120 efi_loaded_image_t *image,
121 efi_handle_t image_handle)
123 const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
124 int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
125 unsigned long alloc_base, kernel_base;
129 * Allocate space for the decompressed kernel as low as possible.
130 * The region should be 16 MiB aligned, but the first 'slack' bytes
131 * are not used by Linux, so we allow those to be occupied by the
134 status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);
135 if (status != EFI_SUCCESS) {
136 efi_err("Unable to allocate memory for uncompressed kernel.\n");
140 if ((alloc_base % EFI_PHYS_ALIGN) > slack) {
142 * More than 'slack' bytes are already occupied at the base of
143 * the allocation, so we need to advance to the next 16 MiB block.
145 kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);
146 efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",
147 alloc_base, kernel_base);
149 kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);
152 *reserve_addr = kernel_base + slack;
153 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
155 /* now free the parts that we will not use */
156 if (*reserve_addr > alloc_base) {
157 efi_bs_call(free_pages, alloc_base,
158 (*reserve_addr - alloc_base) / EFI_PAGE_SIZE);
159 alloc_size -= *reserve_addr - alloc_base;
161 efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,
162 (alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);
164 *image_addr = kernel_base + TEXT_OFFSET;
167 efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",
168 *image_addr, *reserve_addr);