+static const struct target_desc *
+arm_linux_read_description (struct target_ops *ops)
+{
+ CORE_ADDR arm_hwcap = 0;
+
+ if (have_ptrace_getregset == TRIBOOL_UNKNOWN)
+ {
+ elf_gregset_t gpregs;
+ struct iovec iov;
+ int tid = ptid_get_lwp (inferior_ptid);
+
+ iov.iov_base = &gpregs;
+ iov.iov_len = sizeof (gpregs);
+
+ /* Check if PTRACE_GETREGSET works. */
+ if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, &iov) < 0)
+ have_ptrace_getregset = TRIBOOL_FALSE;
+ else
+ have_ptrace_getregset = TRIBOOL_TRUE;
+ }
+
+ if (target_auxv_search (ops, AT_HWCAP, &arm_hwcap) != 1)
+ {
+ return ops->beneath->to_read_description (ops->beneath);
+ }
+
+ if (arm_hwcap & HWCAP_IWMMXT)
+ return tdesc_arm_with_iwmmxt;
+
+ if (arm_hwcap & HWCAP_VFP)
+ {
+ int pid;
+ char *buf;
+ const struct target_desc * result = NULL;
+
+ /* NEON implies VFPv3-D32 or no-VFP unit. Say that we only support
+ Neon with VFPv3-D32. */
+ if (arm_hwcap & HWCAP_NEON)
+ result = tdesc_arm_with_neon;
+ else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
+ result = tdesc_arm_with_vfpv3;
+ else
+ result = tdesc_arm_with_vfpv2;
+
+ /* Now make sure that the kernel supports reading these
+ registers. Support was added in 2.6.30. */
+ pid = ptid_get_lwp (inferior_ptid);
+ errno = 0;
+ buf = (char *) alloca (VFP_REGS_SIZE);
+ if (ptrace (PTRACE_GETVFPREGS, pid, 0, buf) < 0
+ && errno == EIO)
+ result = NULL;
+
+ return result;
+ }
+
+ return ops->beneath->to_read_description (ops->beneath);
+}
+
+/* Information describing the hardware breakpoint capabilities. */
+struct arm_linux_hwbp_cap
+{
+ gdb_byte arch;
+ gdb_byte max_wp_length;
+ gdb_byte wp_count;
+ gdb_byte bp_count;
+};
+
+/* Since we cannot dynamically allocate subfields of arm_linux_process_info,
+ assume a maximum number of supported break-/watchpoints. */
+#define MAX_BPTS 16
+#define MAX_WPTS 16
+
+/* Get hold of the Hardware Breakpoint information for the target we are
+ attached to. Returns NULL if the kernel doesn't support Hardware
+ breakpoints at all, or a pointer to the information structure. */
+static const struct arm_linux_hwbp_cap *
+arm_linux_get_hwbp_cap (void)
+{
+ /* The info structure we return. */
+ static struct arm_linux_hwbp_cap info;
+
+ /* Is INFO in a good state? -1 means that no attempt has been made to
+ initialize INFO; 0 means an attempt has been made, but it failed; 1
+ means INFO is in an initialized state. */
+ static int available = -1;
+
+ if (available == -1)
+ {
+ int tid;
+ unsigned int val;
+
+ tid = ptid_get_lwp (inferior_ptid);
+ if (ptrace (PTRACE_GETHBPREGS, tid, 0, &val) < 0)
+ available = 0;
+ else
+ {
+ info.arch = (gdb_byte)((val >> 24) & 0xff);
+ info.max_wp_length = (gdb_byte)((val >> 16) & 0xff);
+ info.wp_count = (gdb_byte)((val >> 8) & 0xff);
+ info.bp_count = (gdb_byte)(val & 0xff);
+
+ if (info.wp_count > MAX_WPTS)
+ {
+ warning (_("arm-linux-gdb supports %d hardware watchpoints but target \
+ supports %d"), MAX_WPTS, info.wp_count);
+ info.wp_count = MAX_WPTS;
+ }
+
+ if (info.bp_count > MAX_BPTS)
+ {
+ warning (_("arm-linux-gdb supports %d hardware breakpoints but target \
+ supports %d"), MAX_BPTS, info.bp_count);
+ info.bp_count = MAX_BPTS;
+ }
+ available = (info.arch != 0);
+ }
+ }
+
+ return available == 1 ? &info : NULL;
+}
+
+/* How many hardware breakpoints are available? */
+static int
+arm_linux_get_hw_breakpoint_count (void)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ return cap != NULL ? cap->bp_count : 0;
+}
+
+/* How many hardware watchpoints are available? */
+static int
+arm_linux_get_hw_watchpoint_count (void)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ return cap != NULL ? cap->wp_count : 0;
+}
+
+/* Have we got a free break-/watch-point available for use? Returns -1 if
+ there is not an appropriate resource available, otherwise returns 1. */
+static int
+arm_linux_can_use_hw_breakpoint (struct target_ops *self,
+ enum bptype type,
+ int cnt, int ot)
+{
+ if (type == bp_hardware_watchpoint || type == bp_read_watchpoint
+ || type == bp_access_watchpoint || type == bp_watchpoint)
+ {
+ int count = arm_linux_get_hw_watchpoint_count ();
+
+ if (count == 0)
+ return 0;
+ else if (cnt + ot > count)
+ return -1;
+ }
+ else if (type == bp_hardware_breakpoint)
+ {
+ int count = arm_linux_get_hw_breakpoint_count ();
+
+ if (count == 0)
+ return 0;
+ else if (cnt > count)
+ return -1;
+ }
+ else
+ gdb_assert (FALSE);
+
+ return 1;
+}
+
+/* Enum describing the different types of ARM hardware break-/watch-points. */
+typedef enum
+{
+ arm_hwbp_break = 0,
+ arm_hwbp_load = 1,
+ arm_hwbp_store = 2,
+ arm_hwbp_access = 3
+} arm_hwbp_type;
+
+/* Type describing an ARM Hardware Breakpoint Control register value. */
+typedef unsigned int arm_hwbp_control_t;
+
+/* Structure used to keep track of hardware break-/watch-points. */
+struct arm_linux_hw_breakpoint
+{
+ /* Address to break on, or being watched. */
+ unsigned int address;
+ /* Control register for break-/watch- point. */
+ arm_hwbp_control_t control;
+};
+
+/* Structure containing arrays of per process hardware break-/watchpoints
+ for caching address and control information.
+
+ The Linux ptrace interface to hardware break-/watch-points presents the
+ values in a vector centred around 0 (which is used fo generic information).
+ Positive indicies refer to breakpoint addresses/control registers, negative
+ indices to watchpoint addresses/control registers.
+
+ The Linux vector is indexed as follows:
+ -((i << 1) + 2): Control register for watchpoint i.
+ -((i << 1) + 1): Address register for watchpoint i.
+ 0: Information register.
+ ((i << 1) + 1): Address register for breakpoint i.
+ ((i << 1) + 2): Control register for breakpoint i.
+
+ This structure is used as a per-thread cache of the state stored by the
+ kernel, so that we don't need to keep calling into the kernel to find a
+ free breakpoint.
+
+ We treat break-/watch-points with their enable bit clear as being deleted.
+ */
+struct arm_linux_debug_reg_state
+{
+ /* Hardware breakpoints for this process. */
+ struct arm_linux_hw_breakpoint bpts[MAX_BPTS];
+ /* Hardware watchpoints for this process. */
+ struct arm_linux_hw_breakpoint wpts[MAX_WPTS];
+};
+
+/* Per-process arch-specific data we want to keep. */
+struct arm_linux_process_info
+{
+ /* Linked list. */
+ struct arm_linux_process_info *next;
+ /* The process identifier. */
+ pid_t pid;
+ /* Hardware break-/watchpoints state information. */
+ struct arm_linux_debug_reg_state state;
+
+};
+
+/* Per-thread arch-specific data we want to keep. */
+struct arch_lwp_info
+{
+ /* Non-zero if our copy differs from what's recorded in the thread. */
+ char bpts_changed[MAX_BPTS];
+ char wpts_changed[MAX_WPTS];
+};
+
+static struct arm_linux_process_info *arm_linux_process_list = NULL;
+
+/* Find process data for process PID. */
+
+static struct arm_linux_process_info *
+arm_linux_find_process_pid (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
+
+ for (proc = arm_linux_process_list; proc; proc = proc->next)
+ if (proc->pid == pid)
+ return proc;
+
+ return NULL;
+}
+
+/* Add process data for process PID. Returns newly allocated info
+ object. */
+
+static struct arm_linux_process_info *
+arm_linux_add_process (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
+
+ proc = XCNEW (struct arm_linux_process_info);
+ proc->pid = pid;
+
+ proc->next = arm_linux_process_list;
+ arm_linux_process_list = proc;
+
+ return proc;
+}
+
+/* Get data specific info for process PID, creating it if necessary.
+ Never returns NULL. */
+
+static struct arm_linux_process_info *
+arm_linux_process_info_get (pid_t pid)
+{
+ struct arm_linux_process_info *proc;
+
+ proc = arm_linux_find_process_pid (pid);
+ if (proc == NULL)
+ proc = arm_linux_add_process (pid);
+
+ return proc;
+}
+
+/* Called whenever GDB is no longer debugging process PID. It deletes
+ data structures that keep track of debug register state. */
+
+static void
+arm_linux_forget_process (pid_t pid)
+{
+ struct arm_linux_process_info *proc, **proc_link;
+
+ proc = arm_linux_process_list;
+ proc_link = &arm_linux_process_list;
+
+ while (proc != NULL)
+ {
+ if (proc->pid == pid)
+ {
+ *proc_link = proc->next;
+
+ xfree (proc);
+ return;
+ }
+
+ proc_link = &proc->next;
+ proc = *proc_link;
+ }
+}
+
+/* Get hardware break-/watchpoint state for process PID. */
+
+static struct arm_linux_debug_reg_state *
+arm_linux_get_debug_reg_state (pid_t pid)
+{
+ return &arm_linux_process_info_get (pid)->state;
+}
+
+/* Initialize an ARM hardware break-/watch-point control register value.
+ BYTE_ADDRESS_SELECT is the mask of bytes to trigger on; HWBP_TYPE is the
+ type of break-/watch-point; ENABLE indicates whether the point is enabled.
+ */
+static arm_hwbp_control_t
+arm_hwbp_control_initialize (unsigned byte_address_select,
+ arm_hwbp_type hwbp_type,
+ int enable)
+{
+ gdb_assert ((byte_address_select & ~0xffU) == 0);
+ gdb_assert (hwbp_type != arm_hwbp_break
+ || ((byte_address_select & 0xfU) != 0));
+
+ return (byte_address_select << 5) | (hwbp_type << 3) | (3 << 1) | enable;
+}
+
+/* Does the breakpoint control value CONTROL have the enable bit set? */
+static int
+arm_hwbp_control_is_enabled (arm_hwbp_control_t control)
+{
+ return control & 0x1;
+}
+
+/* Change a breakpoint control word so that it is in the disabled state. */
+static arm_hwbp_control_t
+arm_hwbp_control_disable (arm_hwbp_control_t control)
+{
+ return control & ~0x1;
+}
+
+/* Initialise the hardware breakpoint structure P. The breakpoint will be
+ enabled, and will point to the placed address of BP_TGT. */
+static void
+arm_linux_hw_breakpoint_initialize (struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt,
+ struct arm_linux_hw_breakpoint *p)
+{
+ unsigned mask;
+ CORE_ADDR address = bp_tgt->placed_address = bp_tgt->reqstd_address;
+
+ /* We have to create a mask for the control register which says which bits
+ of the word pointed to by address to break on. */
+ if (arm_pc_is_thumb (gdbarch, address))
+ {
+ mask = 0x3;
+ address &= ~1;
+ }
+ else
+ {
+ mask = 0xf;
+ address &= ~3;
+ }
+
+ p->address = (unsigned int) address;
+ p->control = arm_hwbp_control_initialize (mask, arm_hwbp_break, 1);
+}
+
+/* Get the ARM hardware breakpoint type from the TYPE value we're
+ given when asked to set a watchpoint. */
+static arm_hwbp_type
+arm_linux_get_hwbp_type (enum target_hw_bp_type type)
+{
+ if (type == hw_read)
+ return arm_hwbp_load;
+ else if (type == hw_write)
+ return arm_hwbp_store;
+ else
+ return arm_hwbp_access;
+}
+
+/* Initialize the hardware breakpoint structure P for a watchpoint at ADDR
+ to LEN. The type of watchpoint is given in RW. */
+static void
+arm_linux_hw_watchpoint_initialize (CORE_ADDR addr, int len,
+ enum target_hw_bp_type type,
+ struct arm_linux_hw_breakpoint *p)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ unsigned mask;
+
+ gdb_assert (cap != NULL);
+ gdb_assert (cap->max_wp_length != 0);
+
+ mask = (1 << len) - 1;
+
+ p->address = (unsigned int) addr;
+ p->control = arm_hwbp_control_initialize (mask,
+ arm_linux_get_hwbp_type (type), 1);
+}
+
+/* Are two break-/watch-points equal? */
+static int
+arm_linux_hw_breakpoint_equal (const struct arm_linux_hw_breakpoint *p1,
+ const struct arm_linux_hw_breakpoint *p2)
+{
+ return p1->address == p2->address && p1->control == p2->control;
+}
+
+/* Callback to mark a watch-/breakpoint to be updated in all threads of
+ the current process. */
+
+struct update_registers_data
+{
+ int watch;
+ int index;
+};
+
+static int
+update_registers_callback (struct lwp_info *lwp, void *arg)
+{
+ struct update_registers_data *data = (struct update_registers_data *) arg;
+
+ if (lwp->arch_private == NULL)
+ lwp->arch_private = XCNEW (struct arch_lwp_info);
+
+ /* The actual update is done later just before resuming the lwp,
+ we just mark that the registers need updating. */
+ if (data->watch)
+ lwp->arch_private->wpts_changed[data->index] = 1;
+ else
+ lwp->arch_private->bpts_changed[data->index] = 1;
+
+ /* If the lwp isn't stopped, force it to momentarily pause, so
+ we can update its breakpoint registers. */
+ if (!lwp->stopped)
+ linux_stop_lwp (lwp);
+
+ return 0;
+}
+
+/* Insert the hardware breakpoint (WATCHPOINT = 0) or watchpoint (WATCHPOINT
+ =1) BPT for thread TID. */
+static void
+arm_linux_insert_hw_breakpoint1 (const struct arm_linux_hw_breakpoint* bpt,
+ int watchpoint)