refacotr: remove all c files (#1131)

* refacotr: remove all c files

Use Rust to implement the symbol table generator.
Delete unused header files and c files
Adjust the makefile in the debug directory

Signed-off-by: Godones <chenlinfeng25@outlook.com>

* fix: remove extern "C" rs_* functions

move gen_kallsyms.rs to build-scripts

Signed-off-by: Godones <chenlinfeng25@outlook.com>

build-scripts/gen_kallsyms/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "gen_kallsyms"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

build-scripts/gen_kallsyms/src/main.rs

@@ -0,0 +1,122 @@
+use std::str;
+
+#[derive(Debug, Clone)]
+struct KernelSymbolEntry {
+    vaddr: u64,
+    #[allow(dead_code)]
+    symbol_type: char,
+    symbol: String,
+    symbol_length: usize,
+}
+
+fn symbol_to_write(vaddr: u64, text_vaddr: u64, etext_vaddr: u64) -> bool {
+    vaddr >= text_vaddr && vaddr <= etext_vaddr
+}
+fn read_symbol(line: &str) -> Option<KernelSymbolEntry> {
+    if line.len() > 512 {
+        return None;
+    } // skip line with length >= 512
+    let mut parts = line.split_whitespace();
+    let vaddr = u64::from_str_radix(parts.next()?, 16).ok()?;
+    let symbol_type = parts.next()?.chars().next()?;
+    let symbol = parts.collect::<Vec<_>>().join(" ");
+    if symbol_type != 'T' && symbol_type != 't' {
+        return None;
+    } // local symbol or global symbol in text section
+    if symbol == "$x" {
+        return None;
+    } // skip $x symbol
+    let symbol_length = symbol.len() + 1; // +1 for null terminator
+    Some(KernelSymbolEntry {
+        vaddr,
+        symbol_type,
+        symbol,
+        symbol_length,
+    })
+}
+
+fn read_map() -> (Vec<KernelSymbolEntry>, u64, u64) {
+    let mut symbol_table = Vec::new();
+    let mut text_vaddr = 0;
+    let mut etext_vaddr = 0;
+    let mut line = String::new();
+    loop {
+        let size = std::io::stdin().read_line(&mut line).unwrap();
+        if size == 0 {
+            break;
+        }
+        line = line.trim().to_string();
+        if let Some(entry) = read_symbol(&line) {
+            if entry.symbol.starts_with("_text") {
+                text_vaddr = entry.vaddr;
+            } else if entry.symbol.starts_with("_etext") {
+                etext_vaddr = entry.vaddr;
+            }
+            symbol_table.push(entry);
+        }
+        line.clear();
+    }
+    (symbol_table, text_vaddr, etext_vaddr)
+}
+
+fn generate_result(symbol_table: &[KernelSymbolEntry], text_vaddr: u64, etext_vaddr: u64) {
+    println!(".section .rodata\n");
+    println!(".global kallsyms_address");
+    println!(".align 8\n");
+    println!("kallsyms_address:");
+
+    let mut last_vaddr = 0;
+    let mut total_syms_to_write = 0;
+
+    for entry in symbol_table {
+        if !symbol_to_write(entry.vaddr, text_vaddr, etext_vaddr) || entry.vaddr == last_vaddr {
+            continue;
+        }
+
+        println!("\t.quad\t{:#x}", entry.vaddr);
+        total_syms_to_write += 1;
+        last_vaddr = entry.vaddr;
+    }
+
+    println!("\n.global kallsyms_num");
+    println!(".align 8");
+    println!("kallsyms_num:");
+    println!("\t.quad\t{}", total_syms_to_write);
+
+    println!("\n.global kallsyms_names_index");
+    println!(".align 8");
+    println!("kallsyms_names_index:");
+
+    let mut position = 0;
+    last_vaddr = 0;
+
+    for entry in symbol_table {
+        if !symbol_to_write(entry.vaddr, text_vaddr, etext_vaddr) || entry.vaddr == last_vaddr {
+            continue;
+        }
+
+        println!("\t.quad\t{}", position);
+        position += entry.symbol_length;
+        last_vaddr = entry.vaddr;
+    }
+
+    println!("\n.global kallsyms_names");
+    println!(".align 8");
+    println!("kallsyms_names:");
+
+    last_vaddr = 0;
+
+    for entry in symbol_table {
+        if !symbol_to_write(entry.vaddr, text_vaddr, etext_vaddr) || entry.vaddr == last_vaddr {
+            continue;
+        }
+
+        println!("\t.asciz\t\"{}\"", entry.symbol);
+        last_vaddr = entry.vaddr;
+    }
+}
+
+fn main() {
+    let (symbol_table, text_vaddr, etext_vaddr) = read_map();
+    generate_result(&symbol_table, text_vaddr, etext_vaddr);
+}