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fuchsia / third_party / qemu / 81c7ed41a1b33031f3e4fe24191a998a492044b8 / . / semihosting / arm-compat-semi.c
blob: 7a51fd0737d1568b9da726108e982dbac6210c99 [file] [log] [blame]
/*
* 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 "semihosting/semihost.h"
#include "semihosting/console.h"
#include "semihosting/common-semi.h"
#include "qemu/timer.h"
#include "exec/gdbstub.h"
#ifdef CONFIG_USER_ONLY
#include "qemu.h"
#define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024)
#else
#include "qemu/cutils.h"
#include "hw/loader.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
/**
* common_semi_find_bases: find information about ram and heap base
*
* This function attempts to provide meaningful numbers for RAM and
* HEAP base addresses. The rambase is simply the lowest addressable
* RAM position. For the heapbase we ask the loader to scan the
* address space and the largest available gap by querying the "ROM"
* regions.
*
* Returns: a structure with the numbers we need.
*/
typedef struct LayoutInfo {
target_ulong rambase;
size_t ramsize;
hwaddr heapbase;
hwaddr heaplimit;
} LayoutInfo;
static bool find_ram_cb(Int128 start, Int128 len, const MemoryRegion *mr,
hwaddr offset_in_region, void *opaque)
{
LayoutInfo *info = (LayoutInfo *) opaque;
uint64_t size = int128_get64(len);
if (!mr->ram || mr->readonly) {
return false;
}
if (size > info->ramsize) {
info->rambase = int128_get64(start);
info->ramsize = size;
}
/* search exhaustively for largest RAM */
return false;
}
static LayoutInfo common_semi_find_bases(CPUState *cs)
{
FlatView *fv;
LayoutInfo info = { 0, 0, 0, 0 };
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(cs->as);
flatview_for_each_range(fv, find_ram_cb, &info);
/*
* If we have found the RAM lets iterate through the ROM blobs to
* work out the best place for the remainder of RAM and split it
* equally between stack and heap.
*/
if (info.rambase || info.ramsize > 0) {
RomGap gap = rom_find_largest_gap_between(info.rambase, info.ramsize);
info.heapbase = gap.base;
info.heaplimit = gap.base + gap.size;
}
return info;
}
#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));
}
#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);
}
#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. Eventually we could use a generic
* CPUState helper function here.
*/
static inline bool is_64bit_semihosting(CPUArchState *env)
{
#if defined(TARGET_ARM)
return is_a64(env);
#elif defined(TARGET_RISCV)
return riscv_cpu_mxl(env) != MXL_RV32;
#else
#error un-handled architecture
#endif
}
#define GET_ARG(n) do { \
if (is_64bit_semihosting(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_64bit_semihosting(env) ? \
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_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];
int i;
#ifdef CONFIG_USER_ONLY
TaskState *ts = cs->opaque;
target_ulong limit;
#else
LayoutInfo info = common_semi_find_bases(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
retvals[0] = info.heapbase; /* Heap Base */
retvals[1] = info.heaplimit; /* Heap Limit */
retvals[2] = info.heaplimit; /* Stack base */
retvals[3] = info.heapbase; /* Stack limit. */
#endif
for (i = 0; i < ARRAY_SIZE(retvals); i++) {
bool fail;
if (is_64bit_semihosting(env)) {
fail = put_user_u64(retvals[i], arg0 + i * 8);
} else {
fail = put_user_u32(retvals[i], arg0 + i * 4);
}
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();
}
}