1 /* 2 * arm thread support 3 * 4 * Copyright (c) 2013 Stacey D. Son 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #ifndef TARGET_ARCH_THREAD_H 21 #define TARGET_ARCH_THREAD_H 22 23 /* Compare to arm/arm/vm_machdep.c cpu_set_upcall_kse() */ 24 static inline void target_thread_set_upcall(CPUARMState *env, abi_ulong entry, 25 abi_ulong arg, abi_ulong stack_base, abi_ulong stack_size) 26 { 27 abi_ulong sp; 28 29 /* 30 * Make sure the stack is properly aligned. 31 * arm/include/param.h (STACKLIGN() macro) 32 */ 33 sp = (u_int)(stack_base + stack_size) & ~0x7; 34 35 /* sp = stack base */ 36 env->regs[13] = sp; 37 /* pc = start function entry */ 38 env->regs[15] = entry & 0xfffffffe; 39 /* r0 = arg */ 40 env->regs[0] = arg; 41 env->spsr = ARM_CPU_MODE_USR; 42 /* 43 * Thumb mode is encoded by the low bit in the entry point (since ARM can't 44 * execute at odd addresses). When it's set, set the Thumb bit (T) in the 45 * CPSR. 46 */ 47 cpsr_write(env, (entry & 1) * CPSR_T, CPSR_T, CPSRWriteByInstr); 48 } 49 50 static inline void target_thread_init(struct target_pt_regs *regs, 51 struct image_info *infop) 52 { 53 abi_long stack = infop->start_stack; 54 memset(regs, 0, sizeof(*regs)); 55 regs->ARM_cpsr = ARM_CPU_MODE_USR; 56 /* 57 * Thumb mode is encoded by the low bit in the entry point (since ARM can't 58 * execute at odd addresses). When it's set, set the Thumb bit (T) in the 59 * CPSR. 60 */ 61 if (infop->entry & 1) { 62 regs->ARM_cpsr |= CPSR_T; 63 } 64 regs->ARM_pc = infop->entry & 0xfffffffe; 65 regs->ARM_sp = stack; 66 regs->ARM_lr = infop->entry & 0xfffffffe; 67 /* 68 * FreeBSD kernel passes the ps_strings pointer in r0. This is used by some 69 * programs to set status messages that we see in ps. bsd-user doesn't 70 * support that functionality, so it's ignored. When set to 0, FreeBSD's csu 71 * code ignores it. For the static case, r1 and r2 are effectively ignored 72 * by the csu __startup() routine. For the dynamic case, rtld saves r0 but 73 * generates r1 and r2 and passes them into the csu _startup. 74 * 75 * r0 ps_strings 0 passed since ps arg setting not supported 76 * r1 obj_main ignored by _start(), so 0 passed 77 * r2 cleanup generated by rtld or ignored by _start(), so 0 passed 78 */ 79 } 80 81 #endif /* TARGET_ARCH_THREAD_H */ 82