From 3b273a55348fa8673f02979a959c445e88ca3807 Mon Sep 17 00:00:00 2001
From: Richard Earnshaw <richard.earnshaw@arm.com>
Date: Mon, 12 Apr 2010 13:52:43 +0000
Subject: 2010-04-12 Matthew Gretton-Dann <matthew.gretton-dann@arm.com>
* arm-tdep.h (gdb_regnum): Add ARM_FPSCR_REGNUM
* arm-linux-nat.c (arm_linux_vfp_register_count): New
variable.
(fetch_vfp_registers): New function to fetch VFP registers.
(store_vfp_registers): New function to store VFP registers.
(arm_linux_fetch_inferior_registers): Add support for VFP
registers.
(arm_linux_store_inferior_registers): Likewise.
(arm_linux_read_description): Likewise.
(_initialize_arm_linux_nat): Delay initialising iWMMX tdesc
until we need it.
---
gdb/arm-linux-nat.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 153 insertions(+), 15 deletions(-)
(limited to 'gdb/arm-linux-nat.c')
diff --git a/gdb/arm-linux-nat.c b/gdb/arm-linux-nat.c
index 62f4b06a80f..b2da3d83429 100644
--- a/gdb/arm-linux-nat.c
+++ b/gdb/arm-linux-nat.c
@@ -25,10 +25,12 @@
#include "target.h"
#include "linux-nat.h"
#include "target-descriptions.h"
+#include "auxv.h"
#include "arm-tdep.h"
#include "arm-linux-tdep.h"
+#include <elf/common.h>
#include <sys/user.h>
#include <sys/ptrace.h>
#include <sys/utsname.h>
@@ -41,6 +43,9 @@
#include "gdb_proc_service.h"
#include "features/arm-with-iwmmxt.c"
+#include "features/arm-with-vfpv2.c"
+#include "features/arm-with-vfpv3.c"
+#include "features/arm-with-neon.c"
#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 22
@@ -51,9 +56,25 @@
#define PTRACE_SETWMMXREGS 19
#endif
+#ifndef PTRACE_GETVFPREGS
+#define PTRACE_GETVFPREGS 27
+#define PTRACE_SETVFPREGS 28
+#endif
+
+/* These are in <asm/elf.h> in current kernels. */
+#define HWCAP_VFP 64
+#define HWCAP_IWMMXT 512
+#define HWCAP_NEON 4096
+#define HWCAP_VFPv3 8192
+#define HWCAP_VFPv3D16 16384
+
/* A flag for whether the WMMX registers are available. */
static int arm_linux_has_wmmx_registers;
+/* The number of 64-bit VFP registers we have (expect this to be 0,
+ 16, or 32). */
+static int arm_linux_vfp_register_count;
+
extern int arm_apcs_32;
/* The following variables are used to determine the version of the
@@ -86,6 +107,7 @@ get_thread_id (ptid_t ptid)
tid = PIDGET (ptid);
return tid;
}
+
#define GET_THREAD_ID(PTID) get_thread_id (PTID)
/* Get the value of a particular register from the floating point
@@ -447,6 +469,67 @@ store_wmmx_regs (const struct regcache *regcache)
}
}
+/* Fetch and store VFP Registers. The kernel object has space for 32
+ 64-bit registers, and the FPSCR. This is even when on a VFPv2 or
+ VFPv3D16 target. */
+#define VFP_REGS_SIZE (32 * 8 + 4)
+
+static void
+fetch_vfp_regs (struct regcache *regcache)
+{
+ char regbuf[VFP_REGS_SIZE];
+ int ret, regno, tid;
+
+ /* Get the thread id for the ptrace call. */
+ tid = GET_THREAD_ID (inferior_ptid);
+
+ ret = ptrace (PTRACE_GETVFPREGS, tid, 0, regbuf);
+ if (ret < 0)
+ {
+ warning (_("Unable to fetch VFP registers."));
+ return;
+ }
+
+ for (regno = 0; regno < arm_linux_vfp_register_count; regno++)
+ regcache_raw_supply (regcache, regno + ARM_D0_REGNUM,
+ (char *) regbuf + regno * 8);
+
+ regcache_raw_supply (regcache, ARM_FPSCR_REGNUM,
+ (char *) regbuf + 32 * 8);
+}
+
+static void
+store_vfp_regs (const struct regcache *regcache)
+{
+ char regbuf[VFP_REGS_SIZE];
+ int ret, regno, tid;
+
+ /* Get the thread id for the ptrace call. */
+ tid = GET_THREAD_ID (inferior_ptid);
+
+ ret = ptrace (PTRACE_GETVFPREGS, tid, 0, regbuf);
+ if (ret < 0)
+ {
+ warning (_("Unable to fetch VFP registers (for update)."));
+ return;
+ }
+
+ for (regno = 0; regno < arm_linux_vfp_register_count; regno++)
+ regcache_raw_collect (regcache, regno + ARM_D0_REGNUM,
+ (char *) regbuf + regno * 8);
+
+ regcache_raw_collect (regcache, ARM_FPSCR_REGNUM,
+ (char *) regbuf + 32 * 8);
+
+ ret = ptrace (PTRACE_SETVFPREGS, tid, 0, regbuf);
+
+ if (ret < 0)
+ {
+ warning (_("Unable to store VFP registers."));
+ return;
+ }
+}
+
/* Fetch registers from the child process. Fetch all registers if
regno == -1, otherwise fetch all general registers or all floating
point registers depending upon the value of regno. */
@@ -461,6 +544,8 @@ arm_linux_fetch_inferior_registers (struct target_ops *ops,
fetch_fpregs (regcache);
if (arm_linux_has_wmmx_registers)
fetch_wmmx_regs (regcache);
+ if (arm_linux_vfp_register_count > 0)
+ fetch_vfp_regs (regcache);
}
else
{
@@ -471,6 +556,10 @@ arm_linux_fetch_inferior_registers (struct target_ops *ops,
else if (arm_linux_has_wmmx_registers
&& regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
fetch_wmmx_regs (regcache);
+ else if (arm_linux_vfp_register_count > 0
+ && regno >= ARM_D0_REGNUM
+ && regno <= ARM_D0_REGNUM + arm_linux_vfp_register_count)
+ fetch_vfp_regs (regcache);
}
}
@@ -488,6 +577,8 @@ arm_linux_store_inferior_registers (struct target_ops *ops,
store_fpregs (regcache);
if (arm_linux_has_wmmx_registers)
store_wmmx_regs (regcache);
+ if (arm_linux_vfp_register_count > 0)
+ store_vfp_regs (regcache);
}
else
{
@@ -498,6 +589,10 @@ arm_linux_store_inferior_registers (struct target_ops *ops,
else if (arm_linux_has_wmmx_registers
&& regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
store_wmmx_regs (regcache);
+ else if (arm_linux_vfp_register_count > 0
+ && regno >= ARM_D0_REGNUM
+ && regno <= ARM_D0_REGNUM + arm_linux_vfp_register_count)
+ store_vfp_regs (regcache);
}
}
@@ -578,20 +673,66 @@ get_linux_version (unsigned int *vmajor,
static const struct target_desc *
arm_linux_read_description (struct target_ops *ops)
{
- int ret;
- char regbuf[IWMMXT_REGS_SIZE];
+ CORE_ADDR arm_hwcap = 0;
+ arm_linux_has_wmmx_registers = 0;
+ arm_linux_vfp_register_count = 0;
- ret = ptrace (PTRACE_GETWMMXREGS, GET_THREAD_ID (inferior_ptid),
- 0, regbuf);
- if (ret < 0)
- arm_linux_has_wmmx_registers = 0;
- else
- arm_linux_has_wmmx_registers = 1;
+ if (target_auxv_search (ops, AT_HWCAP, &arm_hwcap) != 1)
+ {
+ return NULL;
+ }
- if (arm_linux_has_wmmx_registers)
- return tdesc_arm_with_iwmmxt;
- else
- return NULL;
+ if (arm_hwcap & HWCAP_IWMMXT)
+ {
+ arm_linux_has_wmmx_registers = 1;
+ if (tdesc_arm_with_iwmmxt == NULL)
+ initialize_tdesc_arm_with_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)
+ {
+ arm_linux_vfp_register_count = 32;
+ if (tdesc_arm_with_neon == NULL)
+ initialize_tdesc_arm_with_neon ();
+ result = tdesc_arm_with_neon;
+ }
+ else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPv3D16)) == HWCAP_VFPv3)
+ {
+ arm_linux_vfp_register_count = 32;
+ if (tdesc_arm_with_vfpv3 == NULL)
+ initialize_tdesc_arm_with_vfpv3 ();
+ result = tdesc_arm_with_vfpv3;
+ }
+ else
+ {
+ arm_linux_vfp_register_count = 16;
+ if (tdesc_arm_with_vfpv2 == NULL)
+ initialize_tdesc_arm_with_vfpv2 ();
+ result = tdesc_arm_with_vfpv2;
+ }
+
+ /* Now make sure that the kernel supports reading these
+ registers. Support was added in 2.6.30. */
+ pid = GET_LWP (inferior_ptid);
+ errno = 0;
+ buf = alloca (VFP_REGS_SIZE);
+ if (ptrace (PTRACE_GETVFPREGS, pid, 0, buf) < 0
+ && errno == EIO)
+ result = NULL;
+
+ return result;
+ }
+
+ return NULL;
}
void _initialize_arm_linux_nat (void);
@@ -614,7 +755,4 @@ _initialize_arm_linux_nat (void)
/* Register the target. */
linux_nat_add_target (t);
-
- /* Initialize the standard target descriptions. */
- initialize_tdesc_arm_with_iwmmxt ();
}
--
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