Use elf symbol table instead of map file for kernel

2 files changed, 31 insertions, 32 deletions

diff --git a/src/kernel/core/kmain.c b/src/kernel/core/kmain.c
index d09a1b5..dd66805 100644
--- a/src/kernel/core/kmain.c
+++ b/src/kernel/core/kmain.c
@@ -69,6 +69,9 @@ void kmain(multiboot_info_t *mbd, int32_t mb_magic) {
 	// to allocate memory ; they just increment it of the allocated quantity
 	void* kernel_data_end = (void*)&k_end_addr;
 
+	elf_shdr_t *elf_sections = (elf_shdr_t*)(mbd->elf_sec.addr + K_HIGHHALF_ADDR);
+	ASSERT(sizeof(elf_shdr_t) == mbd->elf_sec.size);
+
 	dbglog_setup();
 
 	dbg_printf("Hello, kernel world!\n");
@@ -95,6 +98,14 @@ void kmain(multiboot_info_t *mbd, int32_t mb_magic) {
 			kernel_data_end = mod_end_pa;
 	}
 
+	for (unsigned i = 0; i < mbd->elf_sec.num; i++) {
+		elf_sections[i].sh_addr += K_HIGHHALF_ADDR;
+		size_t section_end = elf_sections[i].sh_addr + elf_sections[i].sh_size;
+		void* section_end_pa = (void*)((section_end & 0xFFFFF000) + 0x1000);
+		if (section_end_pa > kernel_data_end)
+			kernel_data_end = section_end_pa;
+	}
+
 	gdt_init(); dbg_printf("GDT set up.\n");
 
 	idt_init(); dbg_printf("IDT set up.\n");
@@ -125,17 +136,13 @@ void kmain(multiboot_info_t *mbd, int32_t mb_magic) {
 	setup_syscall_table();
 	dbg_printf("System calls setup ok.\n");
 
-	// If we have a kernel map, load it now
-	for (unsigned i = 0; i < mbd->mods_count; i++) {
-		char* modname = (char*)mods[i].string;
-		size_t len = mods[i].mod_end - mods[i].mod_start;
-
-		if (strlen(modname) > 4 && strcmp(modname + strlen(modname) - 4, ".map") == 0) {
-			// Copy data to somewhere safe, as it will be modified
-			void* dup_data = malloc(len + 1);
-			memcpy(dup_data, (void*)mods[i].mod_start, len);
-
-			load_kernel_symbol_map((char*)dup_data, len);
+	// Look for kernel symbol table section
+	for (unsigned i = 0; i < mbd->elf_sec.num; i++) {
+		dbg_printf("0x%p section type %d addr 0x%p - 0x%p\n",
+			&elf_sections[i], elf_sections[i].sh_type,
+			elf_sections[i].sh_addr, elf_sections[i].sh_addr + elf_sections[i].sh_size);
+		if (elf_sections[i].sh_type == SHT_SYMTAB) {
+			load_kernel_symbol_table(&elf_sections[i], &elf_sections[elf_sections[i].sh_link]);
 		}
 	}
 
diff --git a/src/kernel/core/sys.c b/src/kernel/core/sys.c
index 725843e..2908868 100644
--- a/src/kernel/core/sys.c
+++ b/src/kernel/core/sys.c
@@ -3,6 +3,8 @@
 #include <thread.h>
 #include <string.h>
 
+#include <elf.h>
+
 #include <btree.h>
 
 
@@ -44,31 +46,21 @@ void sys_panic_assert(const char* assertion, const char* file, int line) {
 
 btree_t *kernel_symbol_map = 0;
 
-void load_kernel_symbol_map(char* text, size_t len) {
+void load_kernel_symbol_table(elf_shdr_t *sym, elf_shdr_t *str) {
 	kernel_symbol_map = create_btree(id_key_cmp_fun, 0);
 	ASSERT (kernel_symbol_map != 0);
 
-	dbg_printf("Loading kernel symbol map...\n");
-
-	char* it = text;
-	while (it < text + len) {
-		char* eol = it;
-		while (eol < text + len && *eol != 0 && *eol != '\n') eol++;
-		if (eol >= text + len) break;
-		*eol = 0;
-
-		if (it[16] == '0' && it[17] == 'x' && it[34] == ' ' && it[49] == ' ') {
-			uint32_t addr = 0;
-			for (unsigned i = 18; i < 34; i++) {
-				addr *= 16;
-				if (it[i] >= '0' && it[i] <= '9') addr += it[i] - '0';
-				if (it[i] >= 'a' && it[i] <= 'f') addr += it[i] - 'a' + 10;
-			}
-			btree_add(kernel_symbol_map, (void*)addr, it + 50);
-		}
+	dbg_printf("Loading kernel symbol table...\n");
 
-		it = eol + 1;
-	} 
+	
+	ASSERT(sym->sh_entsize == sizeof(elf_sym_t));
+	unsigned nsym = sym->sh_size / sym->sh_entsize;
+
+	elf_sym_t *st = (elf_sym_t*)sym->sh_addr;
+	const char* strtab = (const char*)(str->sh_addr);
+	for (unsigned j = 0; j < nsym; j++) {
+		btree_add(kernel_symbol_map, (void*)st[j].st_value, (void*)(strtab + st[j].st_name));
+	}
 }
 
 void kernel_stacktrace(uint32_t ebp, uint32_t eip) {