| 1 | /* |
| 2 | * arm thread support |
| 3 | * |
| 4 | * Copyright (c) 2013 Stacey D. Son |
| 5 | * |
| 6 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 7 | */ |
| 8 | #ifndef TARGET_ARCH_THREAD_H |
| 9 | #define TARGET_ARCH_THREAD_H |
| 10 | |
| 11 | /* Compare to arm/arm/vm_machdep.c cpu_set_upcall_kse() */ |
| 12 | static inline void target_thread_set_upcall(CPUARMState *env, abi_ulong entry, |
| 13 | abi_ulong arg, abi_ulong stack_base, abi_ulong stack_size) |
| 14 | { |
| 15 | abi_ulong sp; |
| 16 | |
| 17 | /* |
| 18 | * Make sure the stack is properly aligned. |
| 19 | * arm/include/param.h (STACKLIGN() macro) |
| 20 | */ |
| 21 | sp = (u_int)(stack_base + stack_size) & ~0x7; |
| 22 | |
| 23 | /* sp = stack base */ |
| 24 | env->regs[13] = sp; |
| 25 | /* pc = start function entry */ |
| 26 | env->regs[15] = entry & 0xfffffffe; |
| 27 | /* r0 = arg */ |
| 28 | env->regs[0] = arg; |
| 29 | env->spsr = ARM_CPU_MODE_USR; |
| 30 | /* |
| 31 | * Thumb mode is encoded by the low bit in the entry point (since ARM can't |
| 32 | * execute at odd addresses). When it's set, set the Thumb bit (T) in the |
| 33 | * CPSR. |
| 34 | */ |
| 35 | cpsr_write(env, (entry & 1) * CPSR_T, CPSR_T, CPSRWriteByInstr); |
| 36 | } |
| 37 | |
| 38 | static inline void target_thread_init(struct target_pt_regs *regs, |
| 39 | struct image_info *infop) |
| 40 | { |
| 41 | abi_long stack = infop->start_stack; |
| 42 | memset(regs, 0, sizeof(*regs)); |
| 43 | regs->ARM_cpsr = ARM_CPU_MODE_USR; |
| 44 | /* |
| 45 | * Thumb mode is encoded by the low bit in the entry point (since ARM can't |
| 46 | * execute at odd addresses). When it's set, set the Thumb bit (T) in the |
| 47 | * CPSR. |
| 48 | */ |
| 49 | if (infop->entry & 1) { |
| 50 | regs->ARM_cpsr |= CPSR_T; |
| 51 | } |
| 52 | regs->ARM_pc = infop->entry & 0xfffffffe; |
| 53 | regs->ARM_sp = stack; |
| 54 | regs->ARM_lr = infop->entry & 0xfffffffe; |
| 55 | /* |
| 56 | * FreeBSD kernel passes the ps_strings pointer in r0. This is used by some |
| 57 | * programs to set status messages that we see in ps. bsd-user doesn't |
| 58 | * support that functionality, so it's ignored. When set to 0, FreeBSD's csu |
| 59 | * code ignores it. For the static case, r1 and r2 are effectively ignored |
| 60 | * by the csu __startup() routine. For the dynamic case, rtld saves r0 but |
| 61 | * generates r1 and r2 and passes them into the csu _startup. |
| 62 | * |
| 63 | * r0 ps_strings 0 passed since ps arg setting not supported |
| 64 | * r1 obj_main ignored by _start(), so 0 passed |
| 65 | * r2 cleanup generated by rtld or ignored by _start(), so 0 passed |
| 66 | */ |
| 67 | } |
| 68 | |
| 69 | #endif /* TARGET_ARCH_THREAD_H */ |