1 /* 2 * Copyright (c) 2020 Intel Corporation 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #include <zephyr/kernel.h> 8 #include <zephyr/kernel_structs.h> 9 #include <kernel_internal.h> 10 #include <kernel_tls.h> 11 #include <zephyr/app_memory/app_memdomain.h> 12 #include <zephyr/sys/util.h> 13 14 #ifdef CONFIG_CPU_CORTEX_M 15 /* 16 * Since Cortex-M does not have the thread ID or process ID 17 * register needed to store TLS pointer at runtime for 18 * toolchain to access thread data. Use a global variable 19 * instead. 20 */ K_APP_DMEM(z_libc_partition)21K_APP_DMEM(z_libc_partition) uintptr_t z_arm_tls_ptr; 22 #endif 23 24 size_t arch_tls_stack_setup(struct k_thread *new_thread, char *stack_ptr) 25 { 26 /* 27 * TLS area for ARM has some data fields following by 28 * thread data and bss. These fields are supposed to be 29 * used by toolchain and OS TLS code to aid in locating 30 * the TLS data/bss. Zephyr currently has no use for 31 * this so we can simply skip these. However, since GCC 32 * is generating code assuming these fields are there, 33 * we simply skip them when setting the TLS pointer. 34 */ 35 36 /* 37 * Since we are populating things backwards, 38 * setup the TLS data/bss area first. 39 */ 40 stack_ptr -= z_tls_data_size(); 41 z_tls_copy(stack_ptr); 42 43 /* Skip two pointers due to toolchain */ 44 stack_ptr -= sizeof(uintptr_t) * 2; 45 46 /* 47 * Set thread TLS pointer which is used in 48 * context switch to point to TLS area. 49 */ 50 new_thread->tls = POINTER_TO_UINT(stack_ptr); 51 52 return (z_tls_data_size() + (sizeof(uintptr_t) * 2)); 53 } 54
