LLEXT: Xtensa: add support for L32R relocation (d676d469) · Commits · Wenxi XU / zephyr

arch/xtensa/core/elf.c

+29 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@

		#include <zephyr/llext/elf.h>
		#include <zephyr/llext/llext.h>
		#include <zephyr/llext/llext_internal.h>
		#include <zephyr/llext/loader.h>
		#include <zephyr/logging/log.h>

		@@ -18,6 +19,7 @@ LOG_MODULE_DECLARE(llext);
		#define R_XTENSA_JMP_SLOT 4
		#define R_XTENSA_RELATIVE 5
		#define R_XTENSA_PLT 6
		#define R_XTENSA_SLOT0_OP 20

		/**
		* @brief Architecture specific function for relocating shared elf
		@@ -49,6 +51,33 @@ void arch_elf_relocate_local(struct llext_loader ldr, struct llext ext,
		break;
		case R_XTENSA_32:
		*got_entry += sh_addr;
		break;
		case R_XTENSA_SLOT0_OP:
		;
		uint8_t opc = (uint8_t )got_entry;

		/* Check the opcode: is this an L32R? And does it have to be relocated? */
		if ((opc[0] & 0xf) != 1 \|\| opc[1] \|\| opc[2])
		break;

		elf_sym_t rsym;

		int ret = llext_seek(ldr, ldr->sects[LLEXT_MEM_SYMTAB].sh_offset +
		ELF_R_SYM(rel->r_info) * sizeof(elf_sym_t));
		if (!ret) {
		ret = llext_read(ldr, &rsym, sizeof(elf_sym_t));
		}
		if (ret)
		return;

		uintptr_t link_addr = (uintptr_t)llext_loaded_sect_ptr(ldr, ext, rsym.st_shndx) +
		rsym.st_value;

		ssize_t value = (link_addr - (((uintptr_t)got_entry + 3) & ~3)) >> 2;

		opc[1] = value & 0xff;
		opc[2] = (value >> 8) & 0xff;

		break;
		default:
		LOG_DBG("unsupported relocation type %u", type);