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 #ifndef _TARGET_ARCH_THREAD_H_ 20 #define _TARGET_ARCH_THREAD_H_ 21 22 /* Compare to arm/arm/vm_machdep.c cpu_set_upcall_kse() */ 23 static inline void target_thread_set_upcall(CPUARMState *env, abi_ulong entry, 24 abi_ulong arg, abi_ulong stack_base, abi_ulong stack_size) 25 { 26 abi_ulong sp; 27 28 /* 29 * Make sure the stack is properly aligned. 30 * arm/include/param.h (STACKLIGN() macro) 31 */ 32 sp = (u_int)(stack_base + stack_size) & ~0x7; 33 34 /* sp = stack base */ 35 env->regs[13] = sp; 36 /* pc = start function entry */ 37 env->regs[15] = entry & 0xfffffffe; 38 /* r0 = arg */ 39 env->regs[0] = arg; 40 env->spsr = ARM_CPU_MODE_USR; 41 /* 42 * Thumb mode is encoded by the low bit in the entry point (since ARM can't 43 * execute at odd addresses). When it's set, set the Thumb bit (T) in the 44 * CPSR. 45 */ 46 cpsr_write(env, (entry & 1) * CPSR_T, CPSR_T, CPSRWriteByInstr); 47 } 48 49 static inline void target_thread_init(struct target_pt_regs *regs, 50 struct image_info *infop) 51 { 52 abi_long stack = infop->start_stack; 53 memset(regs, 0, sizeof(*regs)); 54 regs->ARM_cpsr = ARM_CPU_MODE_USR; 55 /* 56 * Thumb mode is encoded by the low bit in the entry point (since ARM can't 57 * execute at odd addresses). When it's set, set the Thumb bit (T) in the 58 * CPSR. 59 */ 60 if (infop->entry & 1) { 61 regs->ARM_cpsr |= CPSR_T; 62 } 63 regs->ARM_pc = infop->entry & 0xfffffffe; 64 regs->ARM_sp = stack; 65 regs->ARM_lr = infop->entry & 0xfffffffe; 66 /* 67 * FreeBSD kernel passes the ps_strings pointer in r0. This is used by some 68 * programs to set status messages that we see in ps. bsd-user doesn't 69 * support that functionality, so it's ignored. When set to 0, FreeBSD's csu 70 * code ignores it. For the static case, r1 and r2 are effectively ignored 71 * by the csu __startup() routine. For the dynamic case, rtld saves r0 but 72 * generates r1 and r2 and passes them into the csu _startup. 73 * 74 * r0 ps_strings 0 passed since ps arg setting not supported 75 * r1 obj_main ignored by _start(), so 0 passed 76 * r2 cleanup generated by rtld or ignored by _start(), so 0 passed 77 */ 78 } 79 80 #endif /* !_TARGET_ARCH_THREAD_H_ */ 81