klibc-bot for Ben Hutchings
2019-Jan-18 16:42 UTC
[klibc] [klibc:master] Add RISC-V (RV64) port
Commit-ID: f1c1f4f99e60ac0f855a0582b4aebebfbb0804dc
Gitweb:
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=f1c1f4f99e60ac0f855a0582b4aebebfbb0804dc
Author: Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Tue, 17 Jul 2018 02:55:19 +0100
Committer: Ben Hutchings <ben at decadent.org.uk>
CommitDate: Fri, 18 Jan 2019 03:10:14 +0000
[klibc] Add RISC-V (RV64) port
RISC-V is pretty boring. I've cribbed most of this from the MIPS and
AArch64 ports.
I ran into difficulty with initialisation of the gp,register, which I
think has to be process-global - the psABI says that signal handlers
can rely on it, and they could come from any module. This means that
klibc.so and the executable using it need to agree on a single value.
Currently they don't, and this causes gp-relative addressing to go
wrong.
gp-relative addressing is introduced by "relaxation" in the linker,
so I've disabled that for now.
Link: https://www.zytor.com/pipermail/klibc/2018-July/003997.html
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
.../arch/{arm64 => riscv64}/klibc/archconfig.h | 6 +--
.../arch/{mips64 => riscv64}/klibc/archsetjmp.h | 14 +++---
.../arch/{cris => riscv64}/klibc/archsignal.h | 2 +-
.../arch/{arm64 => riscv64}/klibc/archstat.h | 0
usr/include/arch/riscv64/machine/asm.h | 26 +++++++++++
usr/klibc/SYSCALLS.def | 2 +-
usr/klibc/arch/{ppc64 => riscv64}/Kbuild | 8 ++--
usr/klibc/arch/riscv64/MCONFIG | 22 ++++++++++
usr/klibc/arch/riscv64/crt0.S | 22 ++++++++++
usr/klibc/arch/riscv64/setjmp.S | 50 ++++++++++++++++++++++
usr/klibc/arch/riscv64/syscall.S | 13 ++++++
usr/klibc/arch/{mips => riscv64}/sysstub.ph | 15 +++----
12 files changed, 155 insertions(+), 25 deletions(-)
diff --git a/usr/include/arch/arm64/klibc/archconfig.h
b/usr/include/arch/riscv64/klibc/archconfig.h
similarity index 64%
copy from usr/include/arch/arm64/klibc/archconfig.h
copy to usr/include/arch/riscv64/klibc/archconfig.h
index 5e2004b..e85a69c 100644
--- a/usr/include/arch/arm64/klibc/archconfig.h
+++ b/usr/include/arch/riscv64/klibc/archconfig.h
@@ -1,5 +1,5 @@
/*
- * include/arch/arm64/klibc/archconfig.h
+ * include/arch/riscv64/klibc/archconfig.h
*
* See include/klibc/sysconfig.h for the options that can be set in
* this file.
@@ -9,9 +9,7 @@
#ifndef _KLIBC_ARCHCONFIG_H
#define _KLIBC_ARCHCONFIG_H
-/* Use rt_* signals */
-#define _KLIBC_USE_RT_SIG 1
+/* We have an MMU but no fork() syscall */
#define _KLIBC_NO_MMU 0
-#define _KLIBC_REAL_VFORK 1
#endif /* _KLIBC_ARCHCONFIG_H */
diff --git a/usr/include/arch/mips64/klibc/archsetjmp.h
b/usr/include/arch/riscv64/klibc/archsetjmp.h
similarity index 67%
copy from usr/include/arch/mips64/klibc/archsetjmp.h
copy to usr/include/arch/riscv64/klibc/archsetjmp.h
index bfca777..97d6b6b 100644
--- a/usr/include/arch/mips64/klibc/archsetjmp.h
+++ b/usr/include/arch/riscv64/klibc/archsetjmp.h
@@ -1,11 +1,12 @@
/*
- * arch/mips64/include/klibc/archsetjmp.h
+ * arch/riscv64/include/klibc/archsetjmp.h
*/
#ifndef _KLIBC_ARCHSETJMP_H
#define _KLIBC_ARCHSETJMP_H
struct __jmp_buf {
+ unsigned long __pc;
unsigned long __s0;
unsigned long __s1;
unsigned long __s2;
@@ -14,12 +15,13 @@ struct __jmp_buf {
unsigned long __s5;
unsigned long __s6;
unsigned long __s7;
- unsigned long __gp;
- unsigned long __sp;
unsigned long __s8;
- unsigned long __ra;
-} __attribute__ ((aligned(8)));
+ unsigned long __s9;
+ unsigned long __s10;
+ unsigned long __s11;
+ unsigned long __sp;
+};
typedef struct __jmp_buf jmp_buf[1];
-#endif /* _KLIBC_ARCHSETJMP_H */
+#endif /* _SETJMP_H */
diff --git a/usr/include/arch/cris/klibc/archsignal.h
b/usr/include/arch/riscv64/klibc/archsignal.h
similarity index 82%
copy from usr/include/arch/cris/klibc/archsignal.h
copy to usr/include/arch/riscv64/klibc/archsignal.h
index 7fa7454..560a951 100644
--- a/usr/include/arch/cris/klibc/archsignal.h
+++ b/usr/include/arch/riscv64/klibc/archsignal.h
@@ -1,5 +1,5 @@
/*
- * arch/cris/include/klibc/archsignal.h
+ * arch/riscv/include/klibc/archsignal.h
*
* Architecture-specific signal definitions
*
diff --git a/usr/include/arch/arm64/klibc/archstat.h
b/usr/include/arch/riscv64/klibc/archstat.h
similarity index 100%
copy from usr/include/arch/arm64/klibc/archstat.h
copy to usr/include/arch/riscv64/klibc/archstat.h
diff --git a/usr/include/arch/riscv64/machine/asm.h
b/usr/include/arch/riscv64/machine/asm.h
new file mode 100644
index 0000000..9effc93
--- /dev/null
+++ b/usr/include/arch/riscv64/machine/asm.h
@@ -0,0 +1,26 @@
+/*
+ * arch/riscv64/include/machine/asm.h
+ *
+ * Mostly cribbed from mips.
+ */
+
+#ifndef _MACHINE_ASM_H
+#define _MACHINE_ASM_H
+
+/*
+ * ENTRY - declare entry point
+ */
+#define ENTRY(symbol) \
+ .globl symbol; \
+ .align 2; \
+ .type symbol, @function; \
+symbol:
+
+/*
+ * END - mark end of function
+ */
+#define END(function) \
+ .size function, . - function
+
+
+#endif /* _MACHINE_ASM_H */
diff --git a/usr/klibc/SYSCALLS.def b/usr/klibc/SYSCALLS.def
index 64d7b0c..8ebe835 100644
--- a/usr/klibc/SYSCALLS.def
+++ b/usr/klibc/SYSCALLS.def
@@ -21,7 +21,7 @@ void _exit,exit::_exit(int);
<?!ia64> pid_t clone::__clone(unsigned long, void *);
<?ia64> pid_t clone::__clone2(unsigned long, void *, void *);
# if ! _KLIBC_NO_MMU
-<!sparc,sparc64,ia64,arm64> pid_t fork();
+<!sparc,sparc64,ia64,arm64,riscv64> pid_t fork();
<sparc,sparc64> pid_t fork at forkish();
#endif
#if _KLIBC_REAL_VFORK
diff --git a/usr/klibc/arch/ppc64/Kbuild b/usr/klibc/arch/riscv64/Kbuild
similarity index 60%
copy from usr/klibc/arch/ppc64/Kbuild
copy to usr/klibc/arch/riscv64/Kbuild
index a39e91f..242ac5b 100644
--- a/usr/klibc/arch/ppc64/Kbuild
+++ b/usr/klibc/arch/riscv64/Kbuild
@@ -1,8 +1,8 @@
+# -*- makefile -*-
#
-# klibc files for ppc64
-#
-
-klib-y := setjmp.o syscall.o
+# klibc files for riscv64
always := crt0.o
targets := crt0.o
+
+klib-y := setjmp.o syscall.o
diff --git a/usr/klibc/arch/riscv64/MCONFIG b/usr/klibc/arch/riscv64/MCONFIG
new file mode 100644
index 0000000..38703d9
--- /dev/null
+++ b/usr/klibc/arch/riscv64/MCONFIG
@@ -0,0 +1,22 @@
+# -*- makefile -*-
+#
+# arch/riscv64/MCONFIG
+#
+# Special rules for this architecture. Note that this is actually
+# included from the main Makefile, and that pathnames should be
+# accordingly.
+#
+
+# We should get klibc.so and the executables to agree on what gp
+# should be. For now, disable gp-relative addressing.
+KLIBCLDFLAGS = --no-relax
+KLIBCOPTFLAGS += -Os -fomit-frame-pointer
+ifeq ($(DEBUG),y)
+KLIBCOPTFLAGS += -g
+endif
+KLIBCBITSIZE = 64
+
+# Normal binaries start at 64 KB, so start the libary at 2 MB.
+KLIBCSHAREDFLAGS =-Ttext 0x00200200
+
+KLIBCARCHINCFLAGS = -I$(KLIBCKERNELOBJ)/arch/riscv/include
diff --git a/usr/klibc/arch/riscv64/crt0.S b/usr/klibc/arch/riscv64/crt0.S
new file mode 100644
index 0000000..76fa3c2
--- /dev/null
+++ b/usr/klibc/arch/riscv64/crt0.S
@@ -0,0 +1,22 @@
+#
+# arch/riscv64/crt0.S
+#
+# Does arch-specific initialization and invokes __libc_init
+# with the appropriate arguments.
+#
+# See __static_init.c or __shared_init.c for the expected
+# arguments.
+#
+
+#include <machine/asm.h>
+
+ENTRY(_start)
+ .option push
+ .option norelax
+ lla gp, __global_pointer$
+ .option pop
+
+ mv a0, sp # Pointer to ELF entry structure
+ mv a1, zero # No onexit pointer
+ jal __libc_init
+END(_start)
diff --git a/usr/klibc/arch/riscv64/setjmp.S b/usr/klibc/arch/riscv64/setjmp.S
new file mode 100644
index 0000000..66e009e
--- /dev/null
+++ b/usr/klibc/arch/riscv64/setjmp.S
@@ -0,0 +1,50 @@
+/*
+ * arch/riscv64/setjmp.S
+ *
+ * setjmp/longjmp for the RISC-V (RV64) architecture
+ *
+ * The jmp_buf is assumed to contain the following, in order:
+ * pc (ra)
+ * s0..s11
+ * sp
+ */
+
+#include <machine/asm.h>
+
+ENTRY(setjmp)
+ sd ra, 0(a0)
+ sd s0, 8(a0)
+ sd s1, 16(a0)
+ sd s2, 24(a0)
+ sd s3, 32(a0)
+ sd s4, 40(a0)
+ sd s5, 48(a0)
+ sd s6, 56(a0)
+ sd s7, 64(a0)
+ sd s8, 72(a0)
+ sd s9, 80(a0)
+ sd s10, 88(a0)
+ sd s11, 96(a0)
+ sd sp, 104(a0)
+ mv a0, zero
+ jr ra
+END(setjmp)
+
+ENTRY(longjmp)
+ ld ra, 0(a0)
+ ld s0, 8(a0)
+ ld s1, 16(a0)
+ ld s2, 24(a0)
+ ld s3, 32(a0)
+ ld s4, 40(a0)
+ ld s5, 48(a0)
+ ld s6, 56(a0)
+ ld s7, 64(a0)
+ ld s8, 72(a0)
+ ld s9, 80(a0)
+ ld s10, 88(a0)
+ ld s11, 96(a0)
+ ld sp, 104(a0)
+ mv a0, a1
+ jr ra
+END(longjmp)
diff --git a/usr/klibc/arch/riscv64/syscall.S b/usr/klibc/arch/riscv64/syscall.S
new file mode 100644
index 0000000..89d9bd2
--- /dev/null
+++ b/usr/klibc/arch/riscv64/syscall.S
@@ -0,0 +1,13 @@
+#include <machine/asm.h>
+#include <asm/unistd.h>
+
+ENTRY(__syscall_common)
+ scall
+ li t0, -4096
+ bleu a0, t0, 1f
+ neg a0, a0
+ lui t0, %hi(errno)
+ sw a0, %lo(errno)(t0)
+ li a0, -1
+1: jr ra
+END(__syscall_common)
diff --git a/usr/klibc/arch/mips/sysstub.ph b/usr/klibc/arch/riscv64/sysstub.ph
similarity index 52%
copy from usr/klibc/arch/mips/sysstub.ph
copy to usr/klibc/arch/riscv64/sysstub.ph
index 3689529..85c1beb 100644
--- a/usr/klibc/arch/mips/sysstub.ph
+++ b/usr/klibc/arch/riscv64/sysstub.ph
@@ -1,13 +1,12 @@
# -*- perl -*-
#
-# arch/mips/sysstub.ph
+# arch/riscv/sysstub.ph
#
# Script to generate system call stubs
#
-# On MIPS, most system calls follow the standard convention, with the
-# system call number in r0 (v0), return an error value in r19 (a3) as
-# well as the return value in r0 (v0).
+# On RISC-V, most system calls follow the standard convention, with the
+# system call number in x17 (a7) and the return value in x10 (a0).
sub make_sysstub($$$$$@) {
my($outputdir, $fname, $type, $sname, $stype, @args) = @_;
@@ -17,12 +16,10 @@ sub make_sysstub($$$$$@) {
print OUT "#include <machine/asm.h>\n";
print OUT "#include <asm/unistd.h>\n";
print OUT "\n";
- print OUT "\t.set noreorder\n";
- print OUT "\n";
- print OUT "LEAF(${fname})\n";
+ print OUT "ENTRY(${fname})\n";
+ print OUT "\tli\ta7, __NR_${sname}\n";
print OUT "\tj\t__syscall_${stype}\n";
- print OUT "\t li\tv0, __NR_${sname}\n";
- print OUT "\tEND(${fname})\n";
+ print OUT "END(${fname})\n";
close(OUT);
}
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