diff options
Diffstat (limited to 'target/arm/arm-semi.c')
| -rw-r--r-- | target/arm/arm-semi.c | 96 |
1 files changed, 51 insertions, 45 deletions
diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c index ddb94e0aba..53e807ab72 100644 --- a/target/arm/arm-semi.c +++ b/target/arm/arm-semi.c @@ -2,6 +2,7 @@ * Arm "Angel" semihosting syscalls * * Copyright (c) 2005, 2007 CodeSourcery. + * Copyright (c) 2019 Linaro * Written by Paul Brook. * * This program is free software; you can redistribute it and/or modify @@ -16,12 +17,18 @@ * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. + * + * ARM Semihosting is documented in: + * Semihosting for AArch32 and AArch64 Release 2.0 + * https://static.docs.arm.com/100863/0200/semihosting.pdf */ #include "qemu/osdep.h" #include "cpu.h" -#include "exec/semihost.h" +#include "hw/semihosting/semihost.h" +#include "hw/semihosting/console.h" +#include "qemu/log.h" #ifdef CONFIG_USER_ONLY #include "qemu.h" @@ -239,6 +246,15 @@ static target_ulong arm_gdb_syscall(ARMCPU *cpu, gdb_syscall_complete_cb cb, put_user_u64(val, args + (n) * 8) : \ put_user_u32(val, args + (n) * 4)) +/* + * Do a semihosting call. + * + * The specification always says that the "return register" either + * returns a specific value or is corrupted, so we don't need to + * report to our caller whether we are returning a value or trying to + * leave the register unchanged. We use 0xdeadbeef as the return value + * when there isn't a defined return value for the call. + */ target_ulong do_arm_semihosting(CPUARMState *env) { ARMCPU *cpu = arm_env_get_cpu(env); @@ -299,32 +315,10 @@ target_ulong do_arm_semihosting(CPUARMState *env) return set_swi_errno(ts, close(arg0)); } case TARGET_SYS_WRITEC: - { - char c; - - if (get_user_u8(c, args)) - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; - /* Write to debug console. stderr is near enough. */ - if (use_gdb_syscalls()) { - return arm_gdb_syscall(cpu, arm_semi_cb, "write,2,%x,1", args); - } else { - return write(STDERR_FILENO, &c, 1); - } - } + qemu_semihosting_console_out(env, args, 1); + return 0xdeadbeef; case TARGET_SYS_WRITE0: - if (!(s = lock_user_string(args))) - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; - len = strlen(s); - if (use_gdb_syscalls()) { - return arm_gdb_syscall(cpu, arm_semi_cb, "write,2,%x,%x", - args, len); - } else { - ret = write(STDERR_FILENO, s, len); - } - unlock_user(s, args, 0); - return ret; + return qemu_semihosting_console_out(env, args, 0); case TARGET_SYS_WRITE: GET_ARG(0); GET_ARG(1); @@ -337,13 +331,15 @@ target_ulong do_arm_semihosting(CPUARMState *env) } else { s = lock_user(VERIFY_READ, arg1, len, 1); if (!s) { - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; + /* Return bytes not written on error */ + return len; } ret = set_swi_errno(ts, write(arg0, s, len)); unlock_user(s, arg1, 0); - if (ret == (uint32_t)-1) - return -1; + if (ret == (uint32_t)-1) { + ret = 0; + } + /* Return bytes not written */ return len - ret; } case TARGET_SYS_READ: @@ -358,19 +354,21 @@ target_ulong do_arm_semihosting(CPUARMState *env) } else { s = lock_user(VERIFY_WRITE, arg1, len, 0); if (!s) { - /* FIXME - should this error code be -TARGET_EFAULT ? */ - return (uint32_t)-1; + /* return bytes not read */ + return len; } do { ret = set_swi_errno(ts, read(arg0, s, len)); } while (ret == -1 && errno == EINTR); unlock_user(s, arg1, len); - if (ret == (uint32_t)-1) - return -1; + if (ret == (uint32_t)-1) { + ret = 0; + } + /* Return bytes not read */ return len - ret; } case TARGET_SYS_READC: - /* XXX: Read from debug console. Not implemented. */ + qemu_log_mask(LOG_UNIMP, "%s: SYS_READC not implemented", __func__); return 0; case TARGET_SYS_ISTTY: GET_ARG(0); @@ -404,7 +402,7 @@ target_ulong do_arm_semihosting(CPUARMState *env) return buf.st_size; } case TARGET_SYS_TMPNAM: - /* XXX: Not implemented. */ + qemu_log_mask(LOG_UNIMP, "%s: SYS_TMPNAM not implemented", __func__); return -1; case TARGET_SYS_REMOVE: GET_ARG(0); @@ -509,14 +507,16 @@ target_ulong do_arm_semihosting(CPUARMState *env) output_size = ts->info->arg_end - ts->info->arg_start; if (!output_size) { - /* We special-case the "empty command line" case (argc==0). - Just provide the terminating 0. */ + /* + * We special-case the "empty command line" case (argc==0). + * Just provide the terminating 0. + */ output_size = 1; } #endif if (output_size > input_size) { - /* Not enough space to store command-line arguments. */ + /* Not enough space to store command-line arguments. */ return -1; } @@ -570,8 +570,10 @@ target_ulong do_arm_semihosting(CPUARMState *env) GET_ARG(0); #ifdef CONFIG_USER_ONLY - /* Some C libraries assume the heap immediately follows .bss, so - allocate it using sbrk. */ + /* + * Some C libraries assume the heap immediately follows .bss, so + * allocate it using sbrk. + */ if (!ts->heap_limit) { abi_ulong ret; @@ -619,7 +621,8 @@ target_ulong do_arm_semihosting(CPUARMState *env) } case TARGET_SYS_EXIT: if (is_a64(env)) { - /* The A64 version of this call takes a parameter block, + /* + * The A64 version of this call takes a parameter block, * so the application-exit type can return a subcode which * is the exit status code from the application. */ @@ -632,14 +635,17 @@ target_ulong do_arm_semihosting(CPUARMState *env) ret = 1; } } else { - /* ARM specifies only Stopped_ApplicationExit as normal - * exit, everything else is considered an error */ + /* + * ARM specifies only Stopped_ApplicationExit as normal + * exit, everything else is considered an error + */ ret = (args == ADP_Stopped_ApplicationExit) ? 0 : 1; } gdb_exit(env, ret); exit(ret); case TARGET_SYS_SYNCCACHE: - /* Clean the D-cache and invalidate the I-cache for the specified + /* + * Clean the D-cache and invalidate the I-cache for the specified * virtual address range. This is a nop for us since we don't * implement caches. This is only present on A64. */ |