From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: Date: Fri, 03 Dec 1999 09:46:17 +0100 From: "Ralf HECKHAUSEN" To: Subject: Re: Kernel Math Emulation again Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Question: Is there any significant difference in execution speed or program size in either of the two solutions (compiling with soft-float or using the kernel math emulation)? Ralf >>> Bill Roman 12/02 11:32 pm >>> Neil Blackwood wrote: > > There is some kernel maths emulation stuff in 2.3.18. > You will need to copy it over to which ever version you are using. It works. > Look for directories math-emu. > You will need to change config files and make files as well. Its fairly > easy. Even I managed it. Thanks, Neil! I had been very optimistic when I found this code in 2.3.18, and was disappointed when it turned out it wouldn't compile in that context. Without your hint, I don't think I would have guessed that transplanting it into a 2.2 kernel would have worked. To save everyone else a few hours of grepping and tweaking, here are instructions and a patch file to add math emulation to the 2.2.13 kernel sources from linuxppc.cs.nmt.edu. 1. Obtain mpc8xx-2.2.13.tgz and linux-2.3.18.tgz from ftp://linuxppc.cs.nmt.edu/pub/linuxppc/embedded/. Untar them into two separate source trees. (Note: all that's needed from 2.3.18 is the math emulator; does anyone know whether that's available separately, or could someone split it out and put it on the FTP site?) 2. Copy the arch/ppc/mathemu directory from the 2.3.18 tree to the 2.2.13 tree. 3. Apply the patch (below). Note that I am building for an MBX, so that's what .config gets patched for. 4. make symlinks config dep clean zImage. The following is the patch. ---------------------------------------------------------------------------- diff -ur linux-mpc8xx-2.2.13/.config linux/.config --- linux-mpc8xx-2.2.13/.config Fri Oct 22 16:08:42 1999 +++ linux/.config Wed Dec 1 17:10:01 1999 @@ -10,9 +10,9 @@ # CONFIG_PPC64 is not set CONFIG_8xx=y # CONFIG_MPC821 is not set -CONFIG_MPC823=y +# CONFIG_MPC823 is not set # CONFIG_MPC850 is not set -# CONFIG_MPC860 is not set +CONFIG_MPC860=y # CONFIG_MPC860T is not set CONFIG_SERIAL_CONSOLE=y # CONFIG_PMAC is not set @@ -20,12 +20,13 @@ # CONFIG_CHRP is not set # CONFIG_ALL_PPC is not set # CONFIG_APUS is not set -# CONFIG_MBX is not set +CONFIG_MBX=y # CONFIG_RPXLITE is not set # CONFIG_RPXCLASSIC is not set -CONFIG_BSEIP=y +# CONFIG_BSEIP is not set # CONFIG_SMP is not set CONFIG_MACH_SPECIFIC=y +CONFIG_MATH_EMULATION=y # # General setup @@ -297,8 +298,7 @@ # MPC8xx CPM Options # CONFIG_SCC_ENET=y -# CONFIG_SCC1_ENET is not set -CONFIG_SCC2_ENET=y +CONFIG_SCC1_ENET=y # CONFIG_FEC_ENET is not set # CONFIG_CPM_IIC is not set # CONFIG_UCODE_PATCH is not set diff -ur linux-mpc8xx-2.2.13/arch/ppc/Makefile linux/arch/ppc/Makefile --- linux-mpc8xx-2.2.13/arch/ppc/Makefile Wed Oct 20 15:33:30 1999 +++ linux/arch/ppc/Makefile Wed Dec 1 16:16:45 1999 @@ -41,6 +41,12 @@ ARCHIVES := arch/ppc/kernel/kernel.o arch/ppc/mm/mm.o arch/ppc/lib/lib.o $(ARCHIVES) CORE_FILES := arch/ppc/kernel/kernel.o arch/ppc/mm/mm.o arch/ppc/lib/lib.o $(CORE_FILES) +ifdef CONFIG_MATH_EMULATION +SUBDIRS += arch/ppc/math-emu +ARCHIVES += arch/ppc/math-emu/math-emu.o +CORE_FILES += arch/ppc/math-emu/math-emu.o +endif + ifdef CONFIG_XMON SUBDIRS += arch/ppc/xmon CORE_FILES += arch/ppc/xmon/x.o diff -ur linux-mpc8xx-2.2.13/arch/ppc/config.in linux/arch/ppc/config.in --- linux-mpc8xx-2.2.13/arch/ppc/config.in Fri Oct 22 14:56:10 1999 +++ linux/arch/ppc/config.in Wed Dec 1 16:29:14 1999 @@ -37,6 +37,15 @@ if [ "$CONFIG_ALL_PPC" != "y" ];then define_bool CONFIG_MACH_SPECIFIC y fi + +if [ "$CONFIG_8xx" = "y" ]; then + bool 'Math emulation' CONFIG_MATH_EMULATION +else + if [ "$CONFIG_PPC64" != "y" ];then + define_bool CONFIG_6xx y + fi +fi + endmenu mainmenu_option next_comment diff -ur linux-mpc8xx-2.2.13/arch/ppc/kernel/Makefile linux/arch/ppc/kernel/Makefile --- linux-mpc8xx-2.2.13/arch/ppc/kernel/Makefile Fri Oct 22 15:21:39 1999 +++ linux/arch/ppc/kernel/Makefile Thu Dec 2 10:34:19 1999 @@ -30,7 +30,7 @@ endif ifeq ($(CONFIG_8xx),y) -O_OBJS += m8xx_setup.o softemu8xx.o ppc8xx_pic.o +O_OBJS += m8xx_setup.o ppc8xx_pic.o ifdef CONFIG_PCI O_OBJS += qspan_pci.o endif diff -ur linux-mpc8xx-2.2.13/arch/ppc/kernel/traps.c linux/arch/ppc/kernel/traps.c --- linux-mpc8xx-2.2.13/arch/ppc/kernel/traps.c Fri Oct 22 14:04:09 1999 +++ linux/arch/ppc/kernel/traps.c Thu Dec 2 10:32:22 1999 @@ -230,12 +230,12 @@ SoftwareEmulation(struct pt_regs *regs) { int errcode; - extern int Soft_emulate_8xx (struct pt_regs *regs); + extern int do_mathemu(struct pt_regs *regs); extern void print_8xx_pte(struct mm_struct *, unsigned long); if (user_mode(regs)) { - if ((errcode = Soft_emulate_8xx(regs))) { + if ((errcode = do_mathemu(regs))) { printk("Software Emulation %s/%d NIP: %lx *NIP: 0x%x code: %x", current->comm,current->pid, regs->nip, *((uint *)regs->nip), errcode); diff -ur linux-mpc8xx-2.2.13/include/asm-ppc/processor.h linux/include/asm-ppc/processor.h --- linux-mpc8xx-2.2.13/include/asm-ppc/processor.h Fri Oct 22 16:10:02 1999 +++ linux/include/asm-ppc/processor.h Wed Dec 1 16:56:20 1999 @@ -57,8 +57,33 @@ #define HID0_BTCD (1<<1) /* Branch target cache disable */ /* fpscr settings */ -#define FPSCR_FX (1<<31) -#define FPSCR_FEX (1<<30) +#define FPSCR_FX 0x80000000 /* FPU exception summary */ +#define FPSCR_FEX 0x40000000 /* FPU enabled exception summary */ +#define FPSCR_VX 0x20000000 /* Invalid operation summary */ +#define FPSCR_OX 0x10000000 /* Overflow exception summary */ +#define FPSCR_UX 0x08000000 /* Underflow exception summary */ +#define FPSCR_ZX 0x04000000 /* Zero-devide exception summary */ +#define FPSCR_XX 0x02000000 /* Inexact exception summary */ +#define FPSCR_VXSNAN 0x01000000 /* Invalid op for SNaN */ +#define FPSCR_VXISI 0x00800000 /* Invalid op for Inv - Inv */ +#define FPSCR_VXIDI 0x00400000 /* Invalid op for Inv / Inv */ +#define FPSCR_VXZDZ 0x00200000 /* Invalid op for Zero / Zero */ +#define FPSCR_VXIMZ 0x00100000 /* Invalid op for Inv * Zero */ +#define FPSCR_VXVC 0x00080000 /* Invalid op for Compare */ +#define FPSCR_FR 0x00040000 /* Fraction rounded */ +#define FPSCR_FI 0x00020000 /* Fraction inexact */ +#define FPSCR_FPRF 0x0001f000 /* FPU Result Flags */ +#define FPSCR_FPCC 0x0000f000 /* FPU Condition Codes */ +#define FPSCR_VXSOFT 0x00000400 /* Invalid op for software request */ +#define FPSCR_VXSQRT 0x00000200 /* Invalid op for square root */ +#define FPSCR_VXCVI 0x00000100 /* Invalid op for integer convert */ +#define FPSCR_VE 0x00000080 /* Invalid op exception enable */ +#define FPSCR_OE 0x00000040 /* IEEE overflow exception enable */ +#define FPSCR_UE 0x00000020 /* IEEE underflow exception enable */ +#define FPSCR_ZE 0x00000010 /* IEEE zero divide exception enable */ +#define FPSCR_XE 0x00000008 /* FP inexact exception enable */ +#define FPSCR_NI 0x00000004 /* FPU non IEEE-Mode */ +#define FPSCR_RN 0x00000003 /* FPU rounding control */ #define _MACH_prep 1 #define _MACH_Pmac 2 /* pmac or pmac clone (non-chrp) */ ** Sent via the linuxppc-embedded mail list. 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