On 12.02.2020 17:28, Christian Biesinger wrote: > On Wed, Feb 12, 2020 at 7:29 AM Alan Hayward wrote: >> >> >> >>> On 11 Feb 2020, at 23:34, Christian Biesinger via gdb-patches wrote: >>> >>> On Tue, Feb 11, 2020 at 4:55 PM Christian Biesinger >>> wrote: >>>> >>>> The floating point register interface has changed to this: >>>> https://github.com/NetBSD/src/blob/trunk/sys/arch/arm/include/reg.h >>>> >>>> It now uses VFP instead of FPA registers. This patch updates >>>> arm-nbsd-nat.c accordingly. >>>> >>>> Tested by compiling on arm-netbsd on qemu. For actually testing, there >>>> seems to be something missing as "info registers" only shows FPA >>>> registers and no VFP ones. I am still investigating why this is; >>>> please let me know if you know. However, I think this is still good >>>> to check in as-is. >>> >>> Hm... this is perhaps because arm_netbsd_nat_target does not implement >>> read_description; if it returned arm_read_description >>> (ARM_FP_TYPE_VFPV2) this may work? >>> >> >> Yes, looks like netbsd isn’t using any target description functionality. >> >> I suspect the code is getting into arm_gdbarch_init() with a null tdesc, >> and then using the AUTO setting. But that’s just a guess. >> >> Implementing read_description as you suggest should help. However, >> read_description should probably do HWCAP checking similar to the >> arm_linux_nat_target and arm_fbsd_nat_target versions. >> >> Without that, I’d worry that your patch below might start writing off the >> end of the regcache that had been allocated for a fewer number of registers. > > Hm... well, I've probably spent entirely too much time on this > already, but just in case there's an easy fix -- Kamil, does NetBSD > provide an API similar to Linux's HWCAP API that would let me check > which VFP version the current CPU is using? It seems AUXV does not > contain HWCAP data on NetBSD, unlike Linux/FreeBSD, though I may be > missing something. > > (Compare arm_fbsd_read_description_auxv / > arm_linux_nat_target::read_description) > > Christian > Thank you for your work. HWCAP in auxv is not supported (although there is a stub for it). Here is a complete algorithm to detect FPU on ARM 32-bit. http://netbsd.org/~kamil/arm-fpu.c >> >>>> >>>> gdb/ChangeLog: >>>> >>>> 2020-02-11 Christian Biesinger >>>> >>>> * arm-nbsd-nat.c (arm_supply_fparegset): Rename to... >>>> (arm_supply_vfpregset): ...this, and update to use VFP registers. >>>> (fetch_fp_register): Update. >>>> (fetch_fp_regs): Update. >>>> (store_fp_register): Update. >>>> (store_fp_regs): Update. >>>> (fetch_elfcore_registers): Update. >>>> --- >>>> gdb/arm-nbsd-nat.c | 80 ++++++++++++++++++++-------------------------- >>>> 1 file changed, 34 insertions(+), 46 deletions(-) >>>> >>>> diff --git a/gdb/arm-nbsd-nat.c b/gdb/arm-nbsd-nat.c >>>> index 11afc289c3..8027f54dfe 100644 >>>> --- a/gdb/arm-nbsd-nat.c >>>> +++ b/gdb/arm-nbsd-nat.c >>>> @@ -65,15 +65,13 @@ arm_supply_gregset (struct regcache *regcache, struct reg *gregset) >>>> } >>>> >>>> static void >>>> -arm_supply_fparegset (struct regcache *regcache, struct fpreg *fparegset) >>>> +arm_supply_vfpregset (struct regcache *regcache, struct fpreg *fpregset) >>>> { >>>> - int regno; >>>> - >>>> - for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) >>>> - regcache->raw_supply (regno, >>>> - (char *) &fparegset->fpr[regno - ARM_F0_REGNUM]); >>>> + struct vfpreg &vfp = fpregset->fpr_vfp; >>>> + for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++) >>>> + regcache->raw_supply (regno, (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]); >>>> >>>> - regcache->raw_supply (ARM_FPS_REGNUM, (char *) &fparegset->fpr_fpsr); >>>> + regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr); >>>> } >>>> >>>> static void >>>> @@ -147,10 +145,10 @@ static void >>>> fetch_fp_register (struct regcache *regcache, int regno) >>>> { >>>> struct fpreg inferior_fp_registers; >>>> - int ret; >>>> + int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (), >>>> + (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> >>>> - ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (), >>>> - (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> + struct vfpreg &vfp = inferior_fp_registers.fpr_vfp; >>>> >>>> if (ret < 0) >>>> { >>>> @@ -158,18 +156,15 @@ fetch_fp_register (struct regcache *regcache, int regno) >>>> return; >>>> } >>>> >>>> - switch (regno) >>>> + if (regno == ARM_FPSCR_REGNUM) >>>> + regcache->raw_supply (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr); >>>> + else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM) >>>> { >>>> - case ARM_FPS_REGNUM: >>>> - regcache->raw_supply (ARM_FPS_REGNUM, >>>> - (char *) &inferior_fp_registers.fpr_fpsr); >>>> - break; >>>> - >>>> - default: >>>> - regcache->raw_supply >>>> - (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]); >>>> - break; >>>> + regcache->raw_supply (regno, >>>> + (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]); >>>> } >>>> + else >>>> + warning (_("Invalid register number.")); >>>> } >>>> >>>> static void >>>> @@ -188,7 +183,7 @@ fetch_fp_regs (struct regcache *regcache) >>>> return; >>>> } >>>> >>>> - arm_supply_fparegset (regcache, &inferior_fp_registers); >>>> + arm_supply_vfpregset (regcache, &inferior_fp_registers); >>>> } >>>> >>>> void >>>> @@ -327,10 +322,9 @@ static void >>>> store_fp_register (const struct regcache *regcache, int regno) >>>> { >>>> struct fpreg inferior_fp_registers; >>>> - int ret; >>>> - >>>> - ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (), >>>> - (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> + int ret = ptrace (PT_GETFPREGS, regcache->ptid ().pid (), >>>> + (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> + struct vfpreg &vfp = inferior_fp_registers.fpr_vfp; >>>> >>>> if (ret < 0) >>>> { >>>> @@ -338,18 +332,15 @@ store_fp_register (const struct regcache *regcache, int regno) >>>> return; >>>> } >>>> >>>> - switch (regno) >>>> + if (regno == ARM_FPSCR_REGNUM) >>>> + regcache->raw_collect (ARM_FPSCR_REGNUM, (char *) &vfp.vfp_fpscr); >>>> + else if (regno >= ARM_D0_REGNUM && regno <= ARM_D31_REGNUM) >>>> { >>>> - case ARM_FPS_REGNUM: >>>> - regcache->raw_collect (ARM_FPS_REGNUM, >>>> - (char *) &inferior_fp_registers.fpr_fpsr); >>>> - break; >>>> - >>>> - default: >>>> - regcache->raw_collect >>>> - (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]); >>>> - break; >>>> + regcache->raw_collect (regno, >>>> + (char *) &vfp.vfp_regs[regno - ARM_D0_REGNUM]); >>>> } >>>> + else >>>> + warning (_("Invalid register number.")); >>>> >>>> ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (), >>>> (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> @@ -361,20 +352,17 @@ store_fp_register (const struct regcache *regcache, int regno) >>>> static void >>>> store_fp_regs (const struct regcache *regcache) >>>> { >>>> - struct fpreg inferior_fp_registers; >>>> - int ret; >>>> - int regno; >>>> + struct fpreg fpregs; >>>> >>>> - >>>> - for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++) >>>> + for (int regno = ARM_D0_REGNUM; regno <= ARM_D31_REGNUM; regno++) >>>> regcache->raw_collect >>>> - (regno, (char *) &inferior_fp_registers.fpr[regno - ARM_F0_REGNUM]); >>>> + (regno, (char *) &fpregs.fpr_vfp.vfp_regs[regno - ARM_D0_REGNUM]); >>>> >>>> - regcache->raw_collect (ARM_FPS_REGNUM, >>>> - (char *) &inferior_fp_registers.fpr_fpsr); >>>> + regcache->raw_collect (ARM_FPSCR_REGNUM, >>>> + (char *) &fpregs.fpr_vfp.vfp_fpscr); >>>> >>>> - ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (), >>>> - (PTRACE_TYPE_ARG3) &inferior_fp_registers, 0); >>>> + int ret = ptrace (PT_SETFPREGS, regcache->ptid ().pid (), >>>> + (PTRACE_TYPE_ARG3) &fpregs, 0); >>>> >>>> if (ret < 0) >>>> warning (_("unable to store floating-point registers")); >>>> @@ -427,7 +415,7 @@ fetch_elfcore_registers (struct regcache *regcache, >>>> /* The memcpy may be unnecessary, but we can't really be sure >>>> of the alignment of the data in the core file. */ >>>> memcpy (&fparegset, core_reg_sect, sizeof (fparegset)); >>>> - arm_supply_fparegset (regcache, &fparegset); >>>> + arm_supply_vfpregset (regcache, &fparegset); >>>> } >>>> break; >>>> >>>> -- >>>> 2.25.0.225.g125e21ebc7-goog >>>> >>