ARM: Implement search for public (aeabi) attributes subsection

get_cpu_arm() scans through the ".ARM.attributes" section of the
ELF file to find the "aeabi" subsection. This subsection contains
general build attributes that records data about the compatibility
of the ELF file.

librz/bin/format/elf/elf_info.c

@@ -844,6 +844,55 @@ static char *get_cpu_mips(ELFOBJ *bin) {
 	return strdup(" Unknown mips ISA");
 }
 
+static char *read_arm_attributes_section(char *ptr, ut32 bytes_to_read, bool isbig) {
+	/* TODO */
+}
+
+/**
+ * Processor-specific section types explained in:
+ * 1. https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst
+ * 2. https://github.com/ARM-software/abi-aa/blob/main/addenda32/addenda32.rst
+ */
+static char *get_cpu_arm(ELFOBJ *bin) {
+	RzBinElfSection *section = Elf_(rz_bin_elf_get_section_with_name)(bin, ".ARM.attributes");
+	if (!section) {
+		return strdup(" Unknown arm ISA");
+	}
+
+	ut64 offset = section->offset;
+	ut64 size = section->size;
+	if (size < 1) {
+		return strdup(" Unknown arm ISA");
+	}
+
+	char *result = malloc(size + 1);
+	if (!result) {
+		return strdup(" Unknown arm ISA");
+	}
+
+	if (rz_buf_read_at(bin->b, offset, (ut8 *)result, size) < 1) {
+		free(result);
+		return strdup(" Unknown arm ISA");
+	}
+
+	char *subsection_ptr = result + 1; // Point to the first subsection (first byte is the format-version)
+	bool isbig = Elf_(rz_bin_elf_is_big_endian)(bin);
+
+	while (subsection_ptr - result < size) {
+		char *ptr = subsection_ptr;
+		ut32 subsection_size = rz_read_ble32(ptr, isbig);
+		ptr += 4;
+
+		if (!strcmp(ptr, "aeabi")) {
+			ptr += strlen("aeabi") + 1; // +1 for the null byte
+			return read_arm_attributes_section(ptr, subsection_size - 10, isbig);
+		}
+		subsection_ptr += subsection_size;
+	}
+
+	return strdup(" Unknown arm ISA");
+}
+
 static bool is_elf_class64(ELFOBJ *bin) {
 	return bin->ehdr.e_ident[EI_CLASS] == ELFCLASS64;
 }
@@ -1459,7 +1508,7 @@ RZ_OWN char *Elf_(rz_bin_elf_get_arch)(RZ_NONNULL ELFOBJ *bin) {
  * \param elf type
  * \return allocated string
  *
- * Only work on mips right now. Use the elf header to deduce the cpu
+ * Only work on mips and arm right now. Use the elf header to deduce the cpu
  */
 RZ_OWN char *Elf_(rz_bin_elf_get_cpu)(RZ_NONNULL ELFOBJ *bin) {
 	rz_return_val_if_fail(bin, NULL);
@@ -1470,6 +1519,8 @@ RZ_OWN char *Elf_(rz_bin_elf_get_cpu)(RZ_NONNULL ELFOBJ *bin) {
 
 	if (bin->ehdr.e_machine == EM_MIPS) {
 		return get_cpu_mips(bin);
+	} else if (bin->ehdr.e_machine == EM_ARM) {
+		return get_cpu_arm(bin);
 	}
 
 	return NULL;