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-rw-r--r--hw/semihosting/arm-compat-semi.c1306
1 files changed, 0 insertions, 1306 deletions
diff --git a/hw/semihosting/arm-compat-semi.c b/hw/semihosting/arm-compat-semi.c
deleted file mode 100644
index 23c6e3edcb..0000000000
--- a/hw/semihosting/arm-compat-semi.c
+++ /dev/null
@@ -1,1306 +0,0 @@
-/*
- *  Semihosting support for systems modeled on the Arm "Angel"
- *  semihosting syscalls design. This includes Arm and RISC-V processors
- *
- *  Copyright (c) 2005, 2007 CodeSourcery.
- *  Copyright (c) 2019 Linaro
- *  Written by Paul Brook.
- *
- *  Copyright © 2020 by Keith Packard <keithp@keithp.com>
- *  Adapted for systems other than ARM, including RISC-V, by Keith Packard
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  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
- *
- *  RISC-V Semihosting is documented in:
- *     RISC-V Semihosting
- *     https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
- */
-
-#include "qemu/osdep.h"
-
-#include "cpu.h"
-#include "hw/semihosting/semihost.h"
-#include "hw/semihosting/console.h"
-#include "hw/semihosting/common-semi.h"
-#include "qemu/log.h"
-#include "qemu/timer.h"
-#ifdef CONFIG_USER_ONLY
-#include "qemu.h"
-
-#define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024)
-#else
-#include "exec/gdbstub.h"
-#include "qemu/cutils.h"
-#ifdef TARGET_ARM
-#include "hw/arm/boot.h"
-#endif
-#include "hw/boards.h"
-#endif
-
-#define TARGET_SYS_OPEN        0x01
-#define TARGET_SYS_CLOSE       0x02
-#define TARGET_SYS_WRITEC      0x03
-#define TARGET_SYS_WRITE0      0x04
-#define TARGET_SYS_WRITE       0x05
-#define TARGET_SYS_READ        0x06
-#define TARGET_SYS_READC       0x07
-#define TARGET_SYS_ISERROR     0x08
-#define TARGET_SYS_ISTTY       0x09
-#define TARGET_SYS_SEEK        0x0a
-#define TARGET_SYS_FLEN        0x0c
-#define TARGET_SYS_TMPNAM      0x0d
-#define TARGET_SYS_REMOVE      0x0e
-#define TARGET_SYS_RENAME      0x0f
-#define TARGET_SYS_CLOCK       0x10
-#define TARGET_SYS_TIME        0x11
-#define TARGET_SYS_SYSTEM      0x12
-#define TARGET_SYS_ERRNO       0x13
-#define TARGET_SYS_GET_CMDLINE 0x15
-#define TARGET_SYS_HEAPINFO    0x16
-#define TARGET_SYS_EXIT        0x18
-#define TARGET_SYS_SYNCCACHE   0x19
-#define TARGET_SYS_EXIT_EXTENDED 0x20
-#define TARGET_SYS_ELAPSED     0x30
-#define TARGET_SYS_TICKFREQ    0x31
-
-/* ADP_Stopped_ApplicationExit is used for exit(0),
- * anything else is implemented as exit(1) */
-#define ADP_Stopped_ApplicationExit     (0x20026)
-
-#ifndef O_BINARY
-#define O_BINARY 0
-#endif
-
-#define GDB_O_RDONLY  0x000
-#define GDB_O_WRONLY  0x001
-#define GDB_O_RDWR    0x002
-#define GDB_O_APPEND  0x008
-#define GDB_O_CREAT   0x200
-#define GDB_O_TRUNC   0x400
-#define GDB_O_BINARY  0
-
-static int gdb_open_modeflags[12] = {
-    GDB_O_RDONLY,
-    GDB_O_RDONLY | GDB_O_BINARY,
-    GDB_O_RDWR,
-    GDB_O_RDWR | GDB_O_BINARY,
-    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,
-    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
-    GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,
-    GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
-    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,
-    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY,
-    GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,
-    GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY
-};
-
-static int open_modeflags[12] = {
-    O_RDONLY,
-    O_RDONLY | O_BINARY,
-    O_RDWR,
-    O_RDWR | O_BINARY,
-    O_WRONLY | O_CREAT | O_TRUNC,
-    O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
-    O_RDWR | O_CREAT | O_TRUNC,
-    O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
-    O_WRONLY | O_CREAT | O_APPEND,
-    O_WRONLY | O_CREAT | O_APPEND | O_BINARY,
-    O_RDWR | O_CREAT | O_APPEND,
-    O_RDWR | O_CREAT | O_APPEND | O_BINARY
-};
-
-typedef enum GuestFDType {
-    GuestFDUnused = 0,
-    GuestFDHost = 1,
-    GuestFDGDB = 2,
-    GuestFDFeatureFile = 3,
-} GuestFDType;
-
-/*
- * Guest file descriptors are integer indexes into an array of
- * these structures (we will dynamically resize as necessary).
- */
-typedef struct GuestFD {
-    GuestFDType type;
-    union {
-        int hostfd;
-        target_ulong featurefile_offset;
-    };
-} GuestFD;
-
-static GArray *guestfd_array;
-
-#ifndef CONFIG_USER_ONLY
-#include "exec/address-spaces.h"
-/*
- * Find the base of a RAM region containing the specified address
- */
-static inline hwaddr
-common_semi_find_region_base(hwaddr addr)
-{
-    MemoryRegion *subregion;
-
-    /*
-     * Find the chunk of R/W memory containing the address.  This is
-     * used for the SYS_HEAPINFO semihosting call, which should
-     * probably be using information from the loaded application.
-     */
-    QTAILQ_FOREACH(subregion, &get_system_memory()->subregions,
-                   subregions_link) {
-        if (subregion->ram && !subregion->readonly) {
-            Int128 top128 = int128_add(int128_make64(subregion->addr),
-                                       subregion->size);
-            Int128 addr128 = int128_make64(addr);
-            if (subregion->addr <= addr && int128_lt(addr128, top128)) {
-                return subregion->addr;
-            }
-        }
-    }
-    return 0;
-}
-#endif
-
-#ifdef TARGET_ARM
-static inline target_ulong
-common_semi_arg(CPUState *cs, int argno)
-{
-    ARMCPU *cpu = ARM_CPU(cs);
-    CPUARMState *env = &cpu->env;
-    if (is_a64(env)) {
-        return env->xregs[argno];
-    } else {
-        return env->regs[argno];
-    }
-}
-
-static inline void
-common_semi_set_ret(CPUState *cs, target_ulong ret)
-{
-    ARMCPU *cpu = ARM_CPU(cs);
-    CPUARMState *env = &cpu->env;
-    if (is_a64(env)) {
-        env->xregs[0] = ret;
-    } else {
-        env->regs[0] = ret;
-    }
-}
-
-static inline bool
-common_semi_sys_exit_extended(CPUState *cs, int nr)
-{
-    return (nr == TARGET_SYS_EXIT_EXTENDED || is_a64(cs->env_ptr));
-}
-
-#ifndef CONFIG_USER_ONLY
-#include "hw/arm/boot.h"
-static inline target_ulong
-common_semi_rambase(CPUState *cs)
-{
-    CPUArchState *env = cs->env_ptr;
-    const struct arm_boot_info *info = env->boot_info;
-    target_ulong sp;
-
-    if (info) {
-        return info->loader_start;
-    }
-
-    if (is_a64(env)) {
-        sp = env->xregs[31];
-    } else {
-        sp = env->regs[13];
-    }
-    return common_semi_find_region_base(sp);
-}
-#endif
-
-#endif /* TARGET_ARM */
-
-#ifdef TARGET_RISCV
-static inline target_ulong
-common_semi_arg(CPUState *cs, int argno)
-{
-    RISCVCPU *cpu = RISCV_CPU(cs);
-    CPURISCVState *env = &cpu->env;
-    return env->gpr[xA0 + argno];
-}
-
-static inline void
-common_semi_set_ret(CPUState *cs, target_ulong ret)
-{
-    RISCVCPU *cpu = RISCV_CPU(cs);
-    CPURISCVState *env = &cpu->env;
-    env->gpr[xA0] = ret;
-}
-
-static inline bool
-common_semi_sys_exit_extended(CPUState *cs, int nr)
-{
-    return (nr == TARGET_SYS_EXIT_EXTENDED || sizeof(target_ulong) == 8);
-}
-
-#ifndef CONFIG_USER_ONLY
-
-static inline target_ulong
-common_semi_rambase(CPUState *cs)
-{
-    RISCVCPU *cpu = RISCV_CPU(cs);
-    CPURISCVState *env = &cpu->env;
-    return common_semi_find_region_base(env->gpr[xSP]);
-}
-#endif
-
-#endif
-
-/*
- * Allocate a new guest file descriptor and return it; if we
- * couldn't allocate a new fd then return -1.
- * This is a fairly simplistic implementation because we don't
- * expect that most semihosting guest programs will make very
- * heavy use of opening and closing fds.
- */
-static int alloc_guestfd(void)
-{
-    guint i;
-
-    if (!guestfd_array) {
-        /* New entries zero-initialized, i.e. type GuestFDUnused */
-        guestfd_array = g_array_new(FALSE, TRUE, sizeof(GuestFD));
-    }
-
-    /* SYS_OPEN should return nonzero handle on success. Start guestfd from 1 */
-    for (i = 1; i < guestfd_array->len; i++) {
-        GuestFD *gf = &g_array_index(guestfd_array, GuestFD, i);
-
-        if (gf->type == GuestFDUnused) {
-            return i;
-        }
-    }
-
-    /* All elements already in use: expand the array */
-    g_array_set_size(guestfd_array, i + 1);
-    return i;
-}
-
-/*
- * Look up the guestfd in the data structure; return NULL
- * for out of bounds, but don't check whether the slot is unused.
- * This is used internally by the other guestfd functions.
- */
-static GuestFD *do_get_guestfd(int guestfd)
-{
-    if (!guestfd_array) {
-        return NULL;
-    }
-
-    if (guestfd <= 0 || guestfd >= guestfd_array->len) {
-        return NULL;
-    }
-
-    return &g_array_index(guestfd_array, GuestFD, guestfd);
-}
-
-/*
- * Associate the specified guest fd (which must have been
- * allocated via alloc_fd() and not previously used) with
- * the specified host/gdb fd.
- */
-static void associate_guestfd(int guestfd, int hostfd)
-{
-    GuestFD *gf = do_get_guestfd(guestfd);
-
-    assert(gf);
-    gf->type = use_gdb_syscalls() ? GuestFDGDB : GuestFDHost;
-    gf->hostfd = hostfd;
-}
-
-/*
- * Deallocate the specified guest file descriptor. This doesn't
- * close the host fd, it merely undoes the work of alloc_fd().
- */
-static void dealloc_guestfd(int guestfd)
-{
-    GuestFD *gf = do_get_guestfd(guestfd);
-
-    assert(gf);
-    gf->type = GuestFDUnused;
-}
-
-/*
- * Given a guest file descriptor, get the associated struct.
- * If the fd is not valid, return NULL. This is the function
- * used by the various semihosting calls to validate a handle
- * from the guest.
- * Note: calling alloc_guestfd() or dealloc_guestfd() will
- * invalidate any GuestFD* obtained by calling this function.
- */
-static GuestFD *get_guestfd(int guestfd)
-{
-    GuestFD *gf = do_get_guestfd(guestfd);
-
-    if (!gf || gf->type == GuestFDUnused) {
-        return NULL;
-    }
-    return gf;
-}
-
-/*
- * The semihosting API has no concept of its errno being thread-safe,
- * as the API design predates SMP CPUs and was intended as a simple
- * real-hardware set of debug functionality. For QEMU, we make the
- * errno be per-thread in linux-user mode; in softmmu it is a simple
- * global, and we assume that the guest takes care of avoiding any races.
- */
-#ifndef CONFIG_USER_ONLY
-static target_ulong syscall_err;
-
-#include "exec/softmmu-semi.h"
-#endif
-
-static inline uint32_t set_swi_errno(CPUState *cs, uint32_t code)
-{
-    if (code == (uint32_t)-1) {
-#ifdef CONFIG_USER_ONLY
-        TaskState *ts = cs->opaque;
-
-        ts->swi_errno = errno;
-#else
-        syscall_err = errno;
-#endif
-    }
-    return code;
-}
-
-static inline uint32_t get_swi_errno(CPUState *cs)
-{
-#ifdef CONFIG_USER_ONLY
-    TaskState *ts = cs->opaque;
-
-    return ts->swi_errno;
-#else
-    return syscall_err;
-#endif
-}
-
-static target_ulong common_semi_syscall_len;
-
-static void common_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
-{
-    target_ulong reg0 = common_semi_arg(cs, 0);
-
-    if (ret == (target_ulong)-1) {
-        errno = err;
-        set_swi_errno(cs, -1);
-        reg0 = ret;
-    } else {
-        /* Fixup syscalls that use nonstardard return conventions.  */
-        switch (reg0) {
-        case TARGET_SYS_WRITE:
-        case TARGET_SYS_READ:
-            reg0 = common_semi_syscall_len - ret;
-            break;
-        case TARGET_SYS_SEEK:
-            reg0 = 0;
-            break;
-        default:
-            reg0 = ret;
-            break;
-        }
-    }
-    common_semi_set_ret(cs, reg0);
-}
-
-static target_ulong common_semi_flen_buf(CPUState *cs)
-{
-    target_ulong sp;
-#ifdef TARGET_ARM
-    /* Return an address in target memory of 64 bytes where the remote
-     * gdb should write its stat struct. (The format of this structure
-     * is defined by GDB's remote protocol and is not target-specific.)
-     * We put this on the guest's stack just below SP.
-     */
-    ARMCPU *cpu = ARM_CPU(cs);
-    CPUARMState *env = &cpu->env;
-
-    if (is_a64(env)) {
-        sp = env->xregs[31];
-    } else {
-        sp = env->regs[13];
-    }
-#endif
-#ifdef TARGET_RISCV
-    RISCVCPU *cpu = RISCV_CPU(cs);
-    CPURISCVState *env = &cpu->env;
-
-    sp = env->gpr[xSP];
-#endif
-
-    return sp - 64;
-}
-
-static void
-common_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err)
-{
-    /* The size is always stored in big-endian order, extract
-       the value. We assume the size always fit in 32 bits.  */
-    uint32_t size;
-    cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) + 32,
-                        (uint8_t *)&size, 4, 0);
-    size = be32_to_cpu(size);
-    common_semi_set_ret(cs, size);
-    errno = err;
-    set_swi_errno(cs, -1);
-}
-
-static int common_semi_open_guestfd;
-
-static void
-common_semi_open_cb(CPUState *cs, target_ulong ret, target_ulong err)
-{
-    if (ret == (target_ulong)-1) {
-        errno = err;
-        set_swi_errno(cs, -1);
-        dealloc_guestfd(common_semi_open_guestfd);
-    } else {
-        associate_guestfd(common_semi_open_guestfd, ret);
-        ret = common_semi_open_guestfd;
-    }
-    common_semi_set_ret(cs, ret);
-}
-
-static target_ulong
-common_semi_gdb_syscall(CPUState *cs, gdb_syscall_complete_cb cb,
-                        const char *fmt, ...)
-{
-    va_list va;
-
-    va_start(va, fmt);
-    gdb_do_syscallv(cb, fmt, va);
-    va_end(va);
-
-    /*
-     * FIXME: in softmmu mode, the gdbstub will schedule our callback
-     * to occur, but will not actually call it to complete the syscall
-     * until after this function has returned and we are back in the
-     * CPU main loop. Therefore callers to this function must not
-     * do anything with its return value, because it is not necessarily
-     * the result of the syscall, but could just be the old value of X0.
-     * The only thing safe to do with this is that the callers of
-     * do_common_semihosting() will write it straight back into X0.
-     * (In linux-user mode, the callback will have happened before
-     * gdb_do_syscallv() returns.)
-     *
-     * We should tidy this up so neither this function nor
-     * do_common_semihosting() return a value, so the mistake of
-     * doing something with the return value is not possible to make.
-     */
-
-    return common_semi_arg(cs, 0);
-}
-
-/*
- * Types for functions implementing various semihosting calls
- * for specific types of guest file descriptor. These must all
- * do the work and return the required return value for the guest,
- * setting the guest errno if appropriate.
- */
-typedef uint32_t sys_closefn(CPUState *cs, GuestFD *gf);
-typedef uint32_t sys_writefn(CPUState *cs, GuestFD *gf,
-                             target_ulong buf, uint32_t len);
-typedef uint32_t sys_readfn(CPUState *cs, GuestFD *gf,
-                            target_ulong buf, uint32_t len);
-typedef uint32_t sys_isattyfn(CPUState *cs, GuestFD *gf);
-typedef uint32_t sys_seekfn(CPUState *cs, GuestFD *gf,
-                            target_ulong offset);
-typedef uint32_t sys_flenfn(CPUState *cs, GuestFD *gf);
-
-static uint32_t host_closefn(CPUState *cs, GuestFD *gf)
-{
-    /*
-     * Only close the underlying host fd if it's one we opened on behalf
-     * of the guest in SYS_OPEN.
-     */
-    if (gf->hostfd == STDIN_FILENO ||
-        gf->hostfd == STDOUT_FILENO ||
-        gf->hostfd == STDERR_FILENO) {
-        return 0;
-    }
-    return set_swi_errno(cs, close(gf->hostfd));
-}
-
-static uint32_t host_writefn(CPUState *cs, GuestFD *gf,
-                             target_ulong buf, uint32_t len)
-{
-    CPUArchState *env = cs->env_ptr;
-    uint32_t ret;
-    char *s = lock_user(VERIFY_READ, buf, len, 1);
-    (void) env; /* Used in arm softmmu lock_user implicitly */
-    if (!s) {
-        /* Return bytes not written on error */
-        return len;
-    }
-    ret = set_swi_errno(cs, write(gf->hostfd, s, len));
-    unlock_user(s, buf, 0);
-    if (ret == (uint32_t)-1) {
-        ret = 0;
-    }
-    /* Return bytes not written */
-    return len - ret;
-}
-
-static uint32_t host_readfn(CPUState *cs, GuestFD *gf,
-                            target_ulong buf, uint32_t len)
-{
-    CPUArchState *env = cs->env_ptr;
-    uint32_t ret;
-    char *s = lock_user(VERIFY_WRITE, buf, len, 0);
-    (void) env; /* Used in arm softmmu lock_user implicitly */
-    if (!s) {
-        /* return bytes not read */
-        return len;
-    }
-    do {
-        ret = set_swi_errno(cs, read(gf->hostfd, s, len));
-    } while (ret == -1 && errno == EINTR);
-    unlock_user(s, buf, len);
-    if (ret == (uint32_t)-1) {
-        ret = 0;
-    }
-    /* Return bytes not read */
-    return len - ret;
-}
-
-static uint32_t host_isattyfn(CPUState *cs, GuestFD *gf)
-{
-    return isatty(gf->hostfd);
-}
-
-static uint32_t host_seekfn(CPUState *cs, GuestFD *gf, target_ulong offset)
-{
-    uint32_t ret = set_swi_errno(cs, lseek(gf->hostfd, offset, SEEK_SET));
-    if (ret == (uint32_t)-1) {
-        return -1;
-    }
-    return 0;
-}
-
-static uint32_t host_flenfn(CPUState *cs, GuestFD *gf)
-{
-    struct stat buf;
-    uint32_t ret = set_swi_errno(cs, fstat(gf->hostfd, &buf));
-    if (ret == (uint32_t)-1) {
-        return -1;
-    }
-    return buf.st_size;
-}
-
-static uint32_t gdb_closefn(CPUState *cs, GuestFD *gf)
-{
-    return common_semi_gdb_syscall(cs, common_semi_cb, "close,%x", gf->hostfd);
-}
-
-static uint32_t gdb_writefn(CPUState *cs, GuestFD *gf,
-                            target_ulong buf, uint32_t len)
-{
-    common_semi_syscall_len = len;
-    return common_semi_gdb_syscall(cs, common_semi_cb, "write,%x,%x,%x",
-                                   gf->hostfd, buf, len);
-}
-
-static uint32_t gdb_readfn(CPUState *cs, GuestFD *gf,
-                           target_ulong buf, uint32_t len)
-{
-    common_semi_syscall_len = len;
-    return common_semi_gdb_syscall(cs, common_semi_cb, "read,%x,%x,%x",
-                                   gf->hostfd, buf, len);
-}
-
-static uint32_t gdb_isattyfn(CPUState *cs, GuestFD *gf)
-{
-    return common_semi_gdb_syscall(cs, common_semi_cb, "isatty,%x", gf->hostfd);
-}
-
-static uint32_t gdb_seekfn(CPUState *cs, GuestFD *gf, target_ulong offset)
-{
-    return common_semi_gdb_syscall(cs, common_semi_cb, "lseek,%x,%x,0",
-                                   gf->hostfd, offset);
-}
-
-static uint32_t gdb_flenfn(CPUState *cs, GuestFD *gf)
-{
-    return common_semi_gdb_syscall(cs, common_semi_flen_cb, "fstat,%x,%x",
-                                   gf->hostfd, common_semi_flen_buf(cs));
-}
-
-#define SHFB_MAGIC_0 0x53
-#define SHFB_MAGIC_1 0x48
-#define SHFB_MAGIC_2 0x46
-#define SHFB_MAGIC_3 0x42
-
-/* Feature bits reportable in feature byte 0 */
-#define SH_EXT_EXIT_EXTENDED (1 << 0)
-#define SH_EXT_STDOUT_STDERR (1 << 1)
-
-static const uint8_t featurefile_data[] = {
-    SHFB_MAGIC_0,
-    SHFB_MAGIC_1,
-    SHFB_MAGIC_2,
-    SHFB_MAGIC_3,
-    SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */
-};
-
-static void init_featurefile_guestfd(int guestfd)
-{
-    GuestFD *gf = do_get_guestfd(guestfd);
-
-    assert(gf);
-    gf->type = GuestFDFeatureFile;
-    gf->featurefile_offset = 0;
-}
-
-static uint32_t featurefile_closefn(CPUState *cs, GuestFD *gf)
-{
-    /* Nothing to do */
-    return 0;
-}
-
-static uint32_t featurefile_writefn(CPUState *cs, GuestFD *gf,
-                                    target_ulong buf, uint32_t len)
-{
-    /* This fd can never be open for writing */
-
-    errno = EBADF;
-    return set_swi_errno(cs, -1);
-}
-
-static uint32_t featurefile_readfn(CPUState *cs, GuestFD *gf,
-                                   target_ulong buf, uint32_t len)
-{
-    CPUArchState *env = cs->env_ptr;
-    uint32_t i;
-    char *s;
-
-    (void) env; /* Used in arm softmmu lock_user implicitly */
-    s = lock_user(VERIFY_WRITE, buf, len, 0);
-    if (!s) {
-        return len;
-    }
-
-    for (i = 0; i < len; i++) {
-        if (gf->featurefile_offset >= sizeof(featurefile_data)) {
-            break;
-        }
-        s[i] = featurefile_data[gf->featurefile_offset];
-        gf->featurefile_offset++;
-    }
-
-    unlock_user(s, buf, len);
-
-    /* Return number of bytes not read */
-    return len - i;
-}
-
-static uint32_t featurefile_isattyfn(CPUState *cs, GuestFD *gf)
-{
-    return 0;
-}
-
-static uint32_t featurefile_seekfn(CPUState *cs, GuestFD *gf,
-                                   target_ulong offset)
-{
-    gf->featurefile_offset = offset;
-    return 0;
-}
-
-static uint32_t featurefile_flenfn(CPUState *cs, GuestFD *gf)
-{
-    return sizeof(featurefile_data);
-}
-
-typedef struct GuestFDFunctions {
-    sys_closefn *closefn;
-    sys_writefn *writefn;
-    sys_readfn *readfn;
-    sys_isattyfn *isattyfn;
-    sys_seekfn *seekfn;
-    sys_flenfn *flenfn;
-} GuestFDFunctions;
-
-static const GuestFDFunctions guestfd_fns[] = {
-    [GuestFDHost] = {
-        .closefn = host_closefn,
-        .writefn = host_writefn,
-        .readfn = host_readfn,
-        .isattyfn = host_isattyfn,
-        .seekfn = host_seekfn,
-        .flenfn = host_flenfn,
-    },
-    [GuestFDGDB] = {
-        .closefn = gdb_closefn,
-        .writefn = gdb_writefn,
-        .readfn = gdb_readfn,
-        .isattyfn = gdb_isattyfn,
-        .seekfn = gdb_seekfn,
-        .flenfn = gdb_flenfn,
-    },
-    [GuestFDFeatureFile] = {
-        .closefn = featurefile_closefn,
-        .writefn = featurefile_writefn,
-        .readfn = featurefile_readfn,
-        .isattyfn = featurefile_isattyfn,
-        .seekfn = featurefile_seekfn,
-        .flenfn = featurefile_flenfn,
-    },
-};
-
-/* Read the input value from the argument block; fail the semihosting
- * call if the memory read fails.
- */
-#ifdef TARGET_ARM
-#define GET_ARG(n) do {                                 \
-    if (is_a64(env)) {                                  \
-        if (get_user_u64(arg ## n, args + (n) * 8)) {   \
-            errno = EFAULT;                             \
-            return set_swi_errno(cs, -1);              \
-        }                                               \
-    } else {                                            \
-        if (get_user_u32(arg ## n, args + (n) * 4)) {   \
-            errno = EFAULT;                             \
-            return set_swi_errno(cs, -1);              \
-        }                                               \
-    }                                                   \
-} while (0)
-
-#define SET_ARG(n, val)                                 \
-    (is_a64(env) ?                                      \
-     put_user_u64(val, args + (n) * 8) :                \
-     put_user_u32(val, args + (n) * 4))
-#endif
-
-#ifdef TARGET_RISCV
-
-/*
- * get_user_ual is defined as get_user_u32 in softmmu-semi.h,
- * we need a macro that fetches a target_ulong
- */
-#define get_user_utl(arg, p)                    \
-    ((sizeof(target_ulong) == 8) ?              \
-     get_user_u64(arg, p) :                     \
-     get_user_u32(arg, p))
-
-/*
- * put_user_ual is defined as put_user_u32 in softmmu-semi.h,
- * we need a macro that stores a target_ulong
- */
-#define put_user_utl(arg, p)                    \
-    ((sizeof(target_ulong) == 8) ?              \
-     put_user_u64(arg, p) :                     \
-     put_user_u32(arg, p))
-
-#define GET_ARG(n) do {                                                 \
-        if (get_user_utl(arg ## n, args + (n) * sizeof(target_ulong))) { \
-            errno = EFAULT;                                             \
-            return set_swi_errno(cs, -1);                              \
-        }                                                               \
-    } while (0)
-
-#define SET_ARG(n, val)                                 \
-    put_user_utl(val, args + (n) * sizeof(target_ulong))
-#endif
-
-/*
- * 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_common_semihosting(CPUState *cs)
-{
-    CPUArchState *env = cs->env_ptr;
-    target_ulong args;
-    target_ulong arg0, arg1, arg2, arg3;
-    target_ulong ul_ret;
-    char * s;
-    int nr;
-    uint32_t ret;
-    uint32_t len;
-    GuestFD *gf;
-    int64_t elapsed;
-
-    (void) env; /* Used implicitly by arm lock_user macro */
-    nr = common_semi_arg(cs, 0) & 0xffffffffU;
-    args = common_semi_arg(cs, 1);
-
-    switch (nr) {
-    case TARGET_SYS_OPEN:
-    {
-        int guestfd;
-
-        GET_ARG(0);
-        GET_ARG(1);
-        GET_ARG(2);
-        s = lock_user_string(arg0);
-        if (!s) {
-            errno = EFAULT;
-            return set_swi_errno(cs, -1);
-        }
-        if (arg1 >= 12) {
-            unlock_user(s, arg0, 0);
-            errno = EINVAL;
-            return set_swi_errno(cs, -1);
-        }
-
-        guestfd = alloc_guestfd();
-        if (guestfd < 0) {
-            unlock_user(s, arg0, 0);
-            errno = EMFILE;
-            return set_swi_errno(cs, -1);
-        }
-
-        if (strcmp(s, ":tt") == 0) {
-            int result_fileno;
-
-            /*
-             * We implement SH_EXT_STDOUT_STDERR, so:
-             *  open for read == stdin
-             *  open for write == stdout
-             *  open for append == stderr
-             */
-            if (arg1 < 4) {
-                result_fileno = STDIN_FILENO;
-            } else if (arg1 < 8) {
-                result_fileno = STDOUT_FILENO;
-            } else {
-                result_fileno = STDERR_FILENO;
-            }
-            associate_guestfd(guestfd, result_fileno);
-            unlock_user(s, arg0, 0);
-            return guestfd;
-        }
-        if (strcmp(s, ":semihosting-features") == 0) {
-            unlock_user(s, arg0, 0);
-            /* We must fail opens for modes other than 0 ('r') or 1 ('rb') */
-            if (arg1 != 0 && arg1 != 1) {
-                dealloc_guestfd(guestfd);
-                errno = EACCES;
-                return set_swi_errno(cs, -1);
-            }
-            init_featurefile_guestfd(guestfd);
-            return guestfd;
-        }
-
-        if (use_gdb_syscalls()) {
-            common_semi_open_guestfd = guestfd;
-            ret = common_semi_gdb_syscall(cs, common_semi_open_cb,
-                                          "open,%s,%x,1a4", arg0, (int)arg2 + 1,
-                                          gdb_open_modeflags[arg1]);
-        } else {
-            ret = set_swi_errno(cs, open(s, open_modeflags[arg1], 0644));
-            if (ret == (uint32_t)-1) {
-                dealloc_guestfd(guestfd);
-            } else {
-                associate_guestfd(guestfd, ret);
-                ret = guestfd;
-            }
-        }
-        unlock_user(s, arg0, 0);
-        return ret;
-    }
-    case TARGET_SYS_CLOSE:
-        GET_ARG(0);
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        ret = guestfd_fns[gf->type].closefn(cs, gf);
-        dealloc_guestfd(arg0);
-        return ret;
-    case TARGET_SYS_WRITEC:
-        qemu_semihosting_console_outc(cs->env_ptr, args);
-        return 0xdeadbeef;
-    case TARGET_SYS_WRITE0:
-        return qemu_semihosting_console_outs(cs->env_ptr, args);
-    case TARGET_SYS_WRITE:
-        GET_ARG(0);
-        GET_ARG(1);
-        GET_ARG(2);
-        len = arg2;
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        return guestfd_fns[gf->type].writefn(cs, gf, arg1, len);
-    case TARGET_SYS_READ:
-        GET_ARG(0);
-        GET_ARG(1);
-        GET_ARG(2);
-        len = arg2;
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        return guestfd_fns[gf->type].readfn(cs, gf, arg1, len);
-    case TARGET_SYS_READC:
-        return qemu_semihosting_console_inc(cs->env_ptr);
-    case TARGET_SYS_ISERROR:
-        GET_ARG(0);
-        return (target_long) arg0 < 0 ? 1 : 0;
-    case TARGET_SYS_ISTTY:
-        GET_ARG(0);
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        return guestfd_fns[gf->type].isattyfn(cs, gf);
-    case TARGET_SYS_SEEK:
-        GET_ARG(0);
-        GET_ARG(1);
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        return guestfd_fns[gf->type].seekfn(cs, gf, arg1);
-    case TARGET_SYS_FLEN:
-        GET_ARG(0);
-
-        gf = get_guestfd(arg0);
-        if (!gf) {
-            errno = EBADF;
-            return set_swi_errno(cs, -1);
-        }
-
-        return guestfd_fns[gf->type].flenfn(cs, gf);
-    case TARGET_SYS_TMPNAM:
-        GET_ARG(0);
-        GET_ARG(1);
-        GET_ARG(2);
-        if (asprintf(&s, "/tmp/qemu-%x%02x", getpid(),
-                     (int) (arg1 & 0xff)) < 0) {
-            return -1;
-        }
-        ul_ret = (target_ulong) -1;
-
-        /* Make sure there's enough space in the buffer */
-        if (strlen(s) < arg2) {
-            char *output = lock_user(VERIFY_WRITE, arg0, arg2, 0);
-            strcpy(output, s);
-            unlock_user(output, arg0, arg2);
-            ul_ret = 0;
-        }
-        free(s);
-        return ul_ret;
-    case TARGET_SYS_REMOVE:
-        GET_ARG(0);
-        GET_ARG(1);
-        if (use_gdb_syscalls()) {
-            ret = common_semi_gdb_syscall(cs, common_semi_cb, "unlink,%s",
-                                          arg0, (int)arg1 + 1);
-        } else {
-            s = lock_user_string(arg0);
-            if (!s) {
-                errno = EFAULT;
-                return set_swi_errno(cs, -1);
-            }
-            ret =  set_swi_errno(cs, remove(s));
-            unlock_user(s, arg0, 0);
-        }
-        return ret;
-    case TARGET_SYS_RENAME:
-        GET_ARG(0);
-        GET_ARG(1);
-        GET_ARG(2);
-        GET_ARG(3);
-        if (use_gdb_syscalls()) {
-            return common_semi_gdb_syscall(cs, common_semi_cb, "rename,%s,%s",
-                                           arg0, (int)arg1 + 1, arg2,
-                                           (int)arg3 + 1);
-        } else {
-            char *s2;
-            s = lock_user_string(arg0);
-            s2 = lock_user_string(arg2);
-            if (!s || !s2) {
-                errno = EFAULT;
-                ret = set_swi_errno(cs, -1);
-            } else {
-                ret = set_swi_errno(cs, rename(s, s2));
-            }
-            if (s2)
-                unlock_user(s2, arg2, 0);
-            if (s)
-                unlock_user(s, arg0, 0);
-            return ret;
-        }
-    case TARGET_SYS_CLOCK:
-        return clock() / (CLOCKS_PER_SEC / 100);
-    case TARGET_SYS_TIME:
-        return set_swi_errno(cs, time(NULL));
-    case TARGET_SYS_SYSTEM:
-        GET_ARG(0);
-        GET_ARG(1);
-        if (use_gdb_syscalls()) {
-            return common_semi_gdb_syscall(cs, common_semi_cb, "system,%s",
-                                           arg0, (int)arg1 + 1);
-        } else {
-            s = lock_user_string(arg0);
-            if (!s) {
-                errno = EFAULT;
-                return set_swi_errno(cs, -1);
-            }
-            ret = set_swi_errno(cs, system(s));
-            unlock_user(s, arg0, 0);
-            return ret;
-        }
-    case TARGET_SYS_ERRNO:
-        return get_swi_errno(cs);
-    case TARGET_SYS_GET_CMDLINE:
-        {
-            /* Build a command-line from the original argv.
-             *
-             * The inputs are:
-             *     * arg0, pointer to a buffer of at least the size
-             *               specified in arg1.
-             *     * arg1, size of the buffer pointed to by arg0 in
-             *               bytes.
-             *
-             * The outputs are:
-             *     * arg0, pointer to null-terminated string of the
-             *               command line.
-             *     * arg1, length of the string pointed to by arg0.
-             */
-
-            char *output_buffer;
-            size_t input_size;
-            size_t output_size;
-            int status = 0;
-#if !defined(CONFIG_USER_ONLY)
-            const char *cmdline;
-#else
-            TaskState *ts = cs->opaque;
-#endif
-            GET_ARG(0);
-            GET_ARG(1);
-            input_size = arg1;
-            /* Compute the size of the output string.  */
-#if !defined(CONFIG_USER_ONLY)
-            cmdline = semihosting_get_cmdline();
-            if (cmdline == NULL) {
-                cmdline = ""; /* Default to an empty line. */
-            }
-            output_size = strlen(cmdline) + 1; /* Count terminating 0. */
-#else
-            unsigned int i;
-
-            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.
-                 */
-                output_size = 1;
-            }
-#endif
-
-            if (output_size > input_size) {
-                /* Not enough space to store command-line arguments.  */
-                errno = E2BIG;
-                return set_swi_errno(cs, -1);
-            }
-
-            /* Adjust the command-line length.  */
-            if (SET_ARG(1, output_size - 1)) {
-                /* Couldn't write back to argument block */
-                errno = EFAULT;
-                return set_swi_errno(cs, -1);
-            }
-
-            /* Lock the buffer on the ARM side.  */
-            output_buffer = lock_user(VERIFY_WRITE, arg0, output_size, 0);
-            if (!output_buffer) {
-                errno = EFAULT;
-                return set_swi_errno(cs, -1);
-            }
-
-            /* Copy the command-line arguments.  */
-#if !defined(CONFIG_USER_ONLY)
-            pstrcpy(output_buffer, output_size, cmdline);
-#else
-            if (output_size == 1) {
-                /* Empty command-line.  */
-                output_buffer[0] = '\0';
-                goto out;
-            }
-
-            if (copy_from_user(output_buffer, ts->info->arg_start,
-                               output_size)) {
-                errno = EFAULT;
-                status = set_swi_errno(cs, -1);
-                goto out;
-            }
-
-            /* Separate arguments by white spaces.  */
-            for (i = 0; i < output_size - 1; i++) {
-                if (output_buffer[i] == 0) {
-                    output_buffer[i] = ' ';
-                }
-            }
-        out:
-#endif
-            /* Unlock the buffer on the ARM side.  */
-            unlock_user(output_buffer, arg0, output_size);
-
-            return status;
-        }
-    case TARGET_SYS_HEAPINFO:
-        {
-            target_ulong retvals[4];
-            target_ulong limit;
-            int i;
-#ifdef CONFIG_USER_ONLY
-            TaskState *ts = cs->opaque;
-#else
-            target_ulong rambase = common_semi_rambase(cs);
-#endif
-
-            GET_ARG(0);
-
-#ifdef CONFIG_USER_ONLY
-            /*
-             * Some C libraries assume the heap immediately follows .bss, so
-             * allocate it using sbrk.
-             */
-            if (!ts->heap_limit) {
-                abi_ulong ret;
-
-                ts->heap_base = do_brk(0);
-                limit = ts->heap_base + COMMON_SEMI_HEAP_SIZE;
-                /* Try a big heap, and reduce the size if that fails.  */
-                for (;;) {
-                    ret = do_brk(limit);
-                    if (ret >= limit) {
-                        break;
-                    }
-                    limit = (ts->heap_base >> 1) + (limit >> 1);
-                }
-                ts->heap_limit = limit;
-            }
-
-            retvals[0] = ts->heap_base;
-            retvals[1] = ts->heap_limit;
-            retvals[2] = ts->stack_base;
-            retvals[3] = 0; /* Stack limit.  */
-#else
-            limit = current_machine->ram_size;
-            /* TODO: Make this use the limit of the loaded application.  */
-            retvals[0] = rambase + limit / 2;
-            retvals[1] = rambase + limit;
-            retvals[2] = rambase + limit; /* Stack base */
-            retvals[3] = rambase; /* Stack limit.  */
-#endif
-
-            for (i = 0; i < ARRAY_SIZE(retvals); i++) {
-                bool fail;
-
-                fail = SET_ARG(i, retvals[i]);
-
-                if (fail) {
-                    /* Couldn't write back to argument block */
-                    errno = EFAULT;
-                    return set_swi_errno(cs, -1);
-                }
-            }
-            return 0;
-        }
-    case TARGET_SYS_EXIT:
-    case TARGET_SYS_EXIT_EXTENDED:
-        if (common_semi_sys_exit_extended(cs, nr)) {
-            /*
-             * The A64 version of SYS_EXIT takes a parameter block,
-             * so the application-exit type can return a subcode which
-             * is the exit status code from the application.
-             * SYS_EXIT_EXTENDED is an a new-in-v2.0 optional function
-             * which allows A32/T32 guests to also provide a status code.
-             */
-            GET_ARG(0);
-            GET_ARG(1);
-
-            if (arg0 == ADP_Stopped_ApplicationExit) {
-                ret = arg1;
-            } else {
-                ret = 1;
-            }
-        } else {
-            /*
-             * The A32/T32 version of SYS_EXIT specifies only
-             * Stopped_ApplicationExit as normal exit, but does not
-             * allow the guest to specify the exit status code.
-             * Everything else is considered an error.
-             */
-            ret = (args == ADP_Stopped_ApplicationExit) ? 0 : 1;
-        }
-        gdb_exit(ret);
-        exit(ret);
-    case TARGET_SYS_ELAPSED:
-        elapsed = get_clock() - clock_start;
-        if (sizeof(target_ulong) == 8) {
-            SET_ARG(0, elapsed);
-        } else {
-            SET_ARG(0, (uint32_t) elapsed);
-            SET_ARG(1, (uint32_t) (elapsed >> 32));
-        }
-        return 0;
-    case TARGET_SYS_TICKFREQ:
-        /* qemu always uses nsec */
-        return 1000000000;
-    case TARGET_SYS_SYNCCACHE:
-        /*
-         * 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.
-         */
-#ifdef TARGET_ARM
-        if (is_a64(cs->env_ptr)) {
-            return 0;
-        }
-#endif
-#ifdef TARGET_RISCV
-        return 0;
-#endif
-        /* fall through -- invalid for A32/T32 */
-    default:
-        fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
-        cpu_dump_state(cs, stderr, 0);
-        abort();
-    }
-}