On 12.02.2020 18:09, Kamil Rytarowski wrote: > 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 > Here is another example with SIMD: http://cvsweb.netbsd.org/bsdweb.cgi/xsrc/external/mit/pixman/dist/pixman/pixman-arm.c.diff?r1=1.1&r2=1.2&f=h >>> >>>>> >>>>> 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 >>>>> >>> > >