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-rw-r--r--tools/prelink-riscv.inc112
1 files changed, 112 insertions, 0 deletions
diff --git a/tools/prelink-riscv.inc b/tools/prelink-riscv.inc
new file mode 100644
index 0000000000..c07d930f7e
--- /dev/null
+++ b/tools/prelink-riscv.inc
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2017 Andes Technology
+ * Chih-Mao Chen <cmchen@andestech.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Statically process runtime relocations on RISC-V ELF images
+ * so that it can be directly executed when loaded at LMA
+ * without fixup. Both RV32 and RV64 are supported.
+ */
+
+#define CONCAT_IMPL(x, y) x##y
+#define CONCAT(x, y) CONCAT_IMPL(x, y)
+#define CONCAT3(x, y, z) CONCAT(CONCAT(x, y), z)
+
+#define prelink_nn CONCAT(prelink, PRELINK_INC_BITS)
+#define uintnn_t CONCAT3(uint, PRELINK_INC_BITS, _t)
+#define get_offset_nn CONCAT(get_offset_, PRELINK_INC_BITS)
+#define Elf_Ehdr CONCAT3(Elf, PRELINK_INC_BITS, _Ehdr)
+#define Elf_Phdr CONCAT3(Elf, PRELINK_INC_BITS, _Phdr)
+#define Elf_Rela CONCAT3(Elf, PRELINK_INC_BITS, _Rela)
+#define Elf_Sym CONCAT3(Elf, PRELINK_INC_BITS, _Sym)
+#define Elf_Dyn CONCAT3(Elf, PRELINK_INC_BITS, _Dyn)
+#define Elf_Addr CONCAT3(Elf, PRELINK_INC_BITS, _Addr)
+#define ELF_R_TYPE CONCAT3(ELF, PRELINK_INC_BITS, _R_TYPE)
+#define ELF_R_SYM CONCAT3(ELF, PRELINK_INC_BITS, _R_SYM)
+
+static void* get_offset_nn (void* data, Elf_Phdr* phdrs, size_t phnum, Elf_Addr addr)
+{
+ Elf_Phdr *p;
+
+ for (p = phdrs; p < phdrs + phnum; ++p)
+ if (p->p_vaddr <= addr && p->p_vaddr + p->p_memsz > addr)
+ return data + p->p_offset + (addr - p->p_vaddr);
+
+ return NULL;
+}
+
+static void prelink_nn(void *data)
+{
+ Elf_Ehdr *ehdr = data;
+ Elf_Phdr *p;
+ Elf_Dyn *dyn;
+ Elf_Rela *r;
+
+ if (ehdr->e_machine != EM_RISCV)
+ die("Machine type is not RISC-V");
+
+ Elf_Phdr *phdrs = data + ehdr->e_phoff;
+
+ Elf_Dyn *dyns = NULL;
+ for (p = phdrs; p < phdrs + ehdr->e_phnum; ++p) {
+ if (p->p_type == PT_DYNAMIC) {
+ dyns = data + p->p_offset;
+ break;
+ }
+ }
+
+ if (dyns == NULL)
+ die("No dynamic section found");
+
+ Elf_Rela *rela_dyn = NULL;
+ size_t rela_count = 0;
+ Elf_Sym *dynsym = NULL;
+ for (dyn = dyns;; ++dyn) {
+ if (dyn->d_tag == DT_NULL)
+ break;
+ else if (dyn->d_tag == DT_RELA)
+ rela_dyn = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
+ else if (dyn->d_tag == DT_RELASZ)
+ rela_count = dyn->d_un.d_val / sizeof(Elf_Rela);
+ else if (dyn->d_tag == DT_SYMTAB)
+ dynsym = get_offset_nn(data, phdrs, ehdr->e_phnum, + dyn->d_un.d_ptr);
+
+ }
+
+ if (rela_dyn == NULL)
+ die("No .rela.dyn found");
+
+ if (dynsym == NULL)
+ die("No .dynsym found");
+
+ for (r = rela_dyn; r < rela_dyn + rela_count; ++r) {
+ void* buf = get_offset_nn(data, phdrs, ehdr->e_phnum, r->r_offset);
+
+ if (buf == NULL)
+ continue;
+
+ if (ELF_R_TYPE(r->r_info) == R_RISCV_RELATIVE)
+ *((uintnn_t*) buf) = r->r_addend;
+ else if (ELF_R_TYPE(r->r_info) == R_RISCV_32)
+ *((uint32_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
+ else if (ELF_R_TYPE(r->r_info) == R_RISCV_64)
+ *((uint64_t*) buf) = dynsym[ELF_R_SYM(r->r_info)].st_value;
+ }
+}
+
+#undef prelink_nn
+#undef uintnn_t
+#undef get_offset_nn
+#undef Elf_Ehdr
+#undef Elf_Phdr
+#undef Elf_Rela
+#undef Elf_Sym
+#undef Elf_Dyn
+#undef Elf_Addr
+#undef ELF_R_TYPE
+#undef ELF_R_SYM
+
+#undef CONCAT_IMPL
+#undef CONCAT
+#undef CONCAT3