kernel/arch/riscv64: Fix elf image loading / add basic relocations

Change-Id: I0f24ef2585ae9f83a8cff8c145276d54298d1c6b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3677
Reviewed-by: Adrien Destugues <[email protected]>

src/system/boot/loader/Jamfile

@@ -70,11 +70,16 @@ for platform in [ MultiBootSubDirSetup ] {
 						BOOT_SUPPORT_ELF64
 					;
 				}
-				case "risc-v" :
+				case "riscv64" :
 				{
 					DEFINES +=
 						BOOT_SUPPORT_ELF64
 					;
+					if $(TARGET_BOOT_PLATFORM) = efi {
+						DEFINES +=
+							_BOOT_PLATFORM_EFI
+						;
+					}
 				}
 				case "m68k" :
 				{

src/system/kernel/arch/riscv64/arch_elf.cpp

@@ -1,13 +1,15 @@
 /*
- * Copyright 2019, Adrien Destugues <[email protected]>
+ * Copyright 2004-2018 Haiku, Inc. All Rights Reserved.
- * Copyright 2010, Ithamar R. Adema <[email protected]>
- * Copyright 2009, Johannes Wischert, [email protected].
- * Copyright 2005, Ingo Weinhold <[email protected]>.
- * Copyright 2002, Travis Geiselbrecht. All rights reserved.
  * Distributed under the terms of the MIT License.
+ * Copyright 2002, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the NewOS License.
  */
 
 
+#ifdef _BOOT_MODE
+#	include <boot/arch.h>
+#endif
+
 #include <KernelExport.h>
 
 #include <elf_priv.h>
@@ -17,10 +19,8 @@
 //#define TRACE_ARCH_ELF
 #ifdef TRACE_ARCH_ELF
 #	define TRACE(x) dprintf x
-#	define CHATTY 1
 #else
 #	define TRACE(x) ;
-#	define CHATTY 0
 #endif
 
 
@@ -29,71 +29,92 @@ static bool
 is_in_image(struct elf_image_info *image, addr_t address)
 {
 	return (address >= image->text_region.start
-			&& address < image->text_region.start + image->text_region.size)
+			&& address < image->text_region.start
+				+ image->text_region.size)
 		|| (address >= image->data_region.start
-			&& address < image->data_region.start + image->data_region.size);
+			&& address < image->data_region.start
+				+ image->data_region.size);
 }
 #endif	// !_BOOT_MODE
 
 
+#ifdef _BOOT_MODE
+status_t
+boot_arch_elf_relocate_rel(preloaded_elf64_image* image, Elf64_Rel* rel,
+	int relLength)
+#else
 int
 arch_elf_relocate_rel(struct elf_image_info *image,
-	struct elf_image_info *resolve_image, Elf64_Rel *rel, int rel_len)
+	struct elf_image_info *resolveImage, Elf64_Rel *rel, int relLength)
+#endif
 {
-	// TODO: rel entries in RISCV64 elf
+	dprintf("arch_elf_relocate_rel: not supported on riscv64\n");
-	return B_NO_ERROR;
+	return B_ERROR;
-}
-
-
-static inline void
-write_32(addr_t P, Elf32_Word value)
-{
-	*(Elf32_Word*)P = value;
-}
-
-
-static inline void
-write_16(addr_t P, Elf32_Word value)
-{
-	// bits 16:29
-	*(Elf32_Half*)P = (Elf32_Half)value;
-}
-
-
-static inline bool
-write_16_check(addr_t P, Elf32_Word value)
-{
-	// bits 15:0
-	if ((value & 0xffff0000) && (~value & 0xffff8000))
-		return false;
-	*(Elf32_Half*)P = (Elf32_Half)value;
-	return true;
-}
-
-
-static inline bool
-write_8(addr_t P, Elf32_Word value)
-{
-	// bits 7:0
-	*(uint8 *)P = (uint8)value;
-	return true;
-}
-
-
-static inline bool
-write_8_check(addr_t P, Elf32_Word value)
-{
-	// bits 7:0
-	if ((value & 0xffffff00) && (~value & 0xffffff80))
-		return false;
-	*(uint8 *)P = (uint8)value;
-	return true;
 }
 
 
+#ifdef _BOOT_MODE
+status_t
+boot_arch_elf_relocate_rela(preloaded_elf64_image* image, Elf64_Rela* rel,
+	int relLength)
+#else
 int
 arch_elf_relocate_rela(struct elf_image_info *image,
-	struct elf_image_info *resolve_image, Elf64_Rela *rel, int rel_len)
+	struct elf_image_info *resolveImage, Elf64_Rela *rel, int relLength)
+#endif
 {
+	for (int i = 0; i < relLength / (int)sizeof(Elf64_Rela); i++) {
+		int type = ELF64_R_TYPE(rel[i].r_info);
+		int symIndex = ELF64_R_SYM(rel[i].r_info);
+		Elf64_Addr symAddr = 0;
+
+		// Resolve the symbol, if any.
+		if (symIndex != 0) {
+			Elf64_Sym* symbol = SYMBOL(image, symIndex);
+
+			status_t status;
+#ifdef _BOOT_MODE
+			status = boot_elf_resolve_symbol(image, symbol,
+				&symAddr);
+#else
+			status = elf_resolve_symbol(image, symbol, resolveImage,
+				&symAddr);
+#endif
+			if (status < B_OK)
+				return status;
+		}
+
+		// Address of the relocation.
+		Elf64_Addr relocAddr = image->text_region.delta
+			+ rel[i].r_offset;
+
+		// Calculate the relocation value.
+		Elf64_Addr relocValue;
+		switch (type) {
+			case R_RISCV_NONE:
+				continue;
+			case R_RISCV_64:
+				relocValue = symAddr + rel[i].r_addend;
+				break;
+			case R_RISCV_RELATIVE:
+				relocValue = image->text_region.delta
+					+ rel[i].r_addend;
+				break;
+			default:
+				dprintf("arch_elf_relocate_rela: unhandled"
+					"relocation type %d\n", type);
+				return B_BAD_DATA;
+		}
+#ifdef _BOOT_MODE
+		boot_elf64_set_relocation(relocAddr, relocValue);
+#else
+		if (!is_in_image(image, relocAddr)) {
+			dprintf("arch_elf_relocate_rela: invalid offset %#lx\n",
+				rel[i].r_offset);
+			return B_BAD_ADDRESS;
+		}
+#endif
+	}
+
 	return B_OK;
 }