riscv32: Initial support for riscv32

This patch provides initial support on the riscv32 architecture, ply
can now be compiled and installed on riscv32 and works fine.

The implementation came from 7f9085b Initial support for riscv64, and
fix s64/u64 data type with t_sllong/t_ullong.

Change-Id: Ia5957927098543d3846f27f18bf290918bc155ed
Signed-off-by: Ism Hong <[email protected]>

README.md

@@ -11,8 +11,8 @@ BPF VM in concert with kprobes and tracepoints to attach probes to
 arbitrary points in the kernel. Most tracers that generate BPF
 bytecode are based on the LLVM based BCC toolchain. ply on the other
 hand has no required external dependencies except for `libc`. In
-addition to `x86_64`, ply also runs on `aarch64`, `arm`, `riscv64` and
-`powerpc`. Adding support for more ISAs is easy.
+addition to `x86_64`, ply also runs on `aarch64`, `arm`, `riscv64`,
+`riscv32`, and `powerpc`. Adding support for more ISAs is easy.
 
 `ply` follows the [Little Language][1] approach of yore, compiling ply
 scripts into Linux [BPF][2] programs that are attached to kprobes and

src/libply/Makefile.am

@@ -12,6 +12,7 @@ EXTRA_DIST = grammar.c grammar.h lexer.c lexer.h \
 	arch/arm.c     \
 	arch/mips.c    \
 	arch/powerpc.c \
+	arch/riscv32.c \
 	arch/riscv64.c \
 	arch/x86_64.c
 

src/libply/arch/riscv32.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright Tobias Waldekranz <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <assert.h>
+
+#include <ply/internal.h>
+
+#define arch_typedef(_a, _t) {					\
+		.ttype = T_TYPEDEF,				\
+		.tdef = { .name = #_a, .type = _t },		\
+	}
+
+struct type t_s8  = arch_typedef(s8,  &t_schar);
+struct type t_u8  = arch_typedef(u8,  &t_uchar);
+struct type t_s16 = arch_typedef(s16, &t_sshort);
+struct type t_u16 = arch_typedef(u16, &t_ushort);
+struct type t_s32 = arch_typedef(s32, &t_sint);
+struct type t_u32 = arch_typedef(u32, &t_uint);
+struct type t_s64 = arch_typedef(s64, &t_sllong);
+struct type t_u64 = arch_typedef(u64, &t_ullong);
+
+static int reg_fprint(struct type *t, FILE *fp, const void *data)
+{
+	return fprintf(fp, "%#lx", *((unsigned long *)data));
+}
+
+struct type t_reg_t = {
+	.ttype = T_TYPEDEF,
+	.tdef = {
+		.name = "reg_t",
+		.type = &t_ulong,
+	},
+
+	.fprint = reg_fprint,
+};
+
+struct tfield f_pt_regs_fields[] = {
+	{ .name = "pc",      .type = &t_reg_t },
+	{ .name = "ra",      .type = &t_reg_t },
+	{ .name = "sp",      .type = &t_reg_t },
+	{ .name = "gp",      .type = &t_reg_t },
+	{ .name = "tp",      .type = &t_reg_t },
+	{ .name = "t0",      .type = &t_reg_t },
+	{ .name = "t1",      .type = &t_reg_t },
+	{ .name = "t2",      .type = &t_reg_t },
+	{ .name = "s0",      .type = &t_reg_t },
+	{ .name = "s1",      .type = &t_reg_t },
+	{ .name = "a0",      .type = &t_reg_t },
+	{ .name = "a1",      .type = &t_reg_t },
+	{ .name = "a2",      .type = &t_reg_t },
+	{ .name = "a3",      .type = &t_reg_t },
+	{ .name = "a4",      .type = &t_reg_t },
+	{ .name = "a5",      .type = &t_reg_t },
+	{ .name = "a6",      .type = &t_reg_t },
+	{ .name = "a7",      .type = &t_reg_t },
+	{ .name = "s2",      .type = &t_reg_t },
+	{ .name = "s3",      .type = &t_reg_t },
+	{ .name = "s4",      .type = &t_reg_t },
+	{ .name = "s5",      .type = &t_reg_t },
+	{ .name = "s6",      .type = &t_reg_t },
+	{ .name = "s7",      .type = &t_reg_t },
+	{ .name = "s8",      .type = &t_reg_t },
+	{ .name = "s9",      .type = &t_reg_t },
+	{ .name = "s10",     .type = &t_reg_t },
+	{ .name = "s11",     .type = &t_reg_t },
+	{ .name = "t3",      .type = &t_reg_t },
+	{ .name = "t4",      .type = &t_reg_t },
+	{ .name = "t5",      .type = &t_reg_t },
+	{ .name = "t6",      .type = &t_reg_t },
+
+	{ .type = NULL }
+};
+
+struct type t_pt_regs = {
+	.ttype = T_STRUCT,
+
+	.sou = {
+		.name = "pt_regs",
+		.fields = f_pt_regs_fields,
+	},
+};
+
+struct type *arch_types[] = {
+	&t_s8, &t_u8,
+	&t_s16, &t_u16,
+	&t_s32, &t_u32,
+	&t_s64, &t_u64,
+	&t_reg_t, &t_pt_regs,
+
+	NULL
+};
+
+const char *arch_register_argument(int num)
+{
+	switch (num) {
+	case 0: return "a0";
+	case 1: return "a1";
+	case 2: return "a2";
+	case 3: return "a3";
+	case 4: return "a4";
+	case 5: return "a5";
+	case 6: return "a6";
+	}
+
+	return NULL;
+}
+
+const char *arch_register_pc(void)
+{
+	return "pc";
+}
+
+const char *arch_register_return(void)
+{
+	return "a0";
+}
+
+__attribute__((constructor))
+static void arch_init(void)
+{
+	type_struct_layout(&t_pt_regs);
+	type_add_list(arch_types);
+}