M include/string.h → include/string.h

@@ -34,5 +34,6 @@ void *memset (void *ptr, int value, size_t num);
 
 unsigned int strlen (const char *str);
 char *strcpy(char *destination, const char *source);
+int strcmp(const char *str1, const char *str2);
 
 #endif

M src/boot/fat.h → src/boot/fat.h

@@ -8,5 +8,6 @@ void *FAT_read_sector_offset(uint32_t lba, uint32_t *offset);
 void *FAT_read_cluster(uint16_t cluster, void *buffer);
 uint16_t FAT_next_cluster(uint16_t cluster);
 int FAT_root_dir_next(int index, char *fname_buffer, uint16_t *first_cluster, uint32_t *file_size);
+void *FAT_find_file(const char *fname);
 
 #endif

M src/kernel/fat.c → src/kernel/fat.c

@@ -184,3 +184,24 @@ return low | high;
     }
 }
 
+void *FAT_find_file(const char *fname) {
+    int i = 0;
+
+    void *addr = (void *)(0);
+    while (1) {
+        char buffer[832];
+        uint16_t first_cluster;
+        uint32_t file_size;
+
+        i = FAT_root_dir_next(i, buffer, &first_cluster, &file_size);
+        if (i <= 0) { break; }
+
+        if (strcmp(buffer, fname) == 0) {
+            // file found
+            addr = FAT_read_sector_offset(data_lba + ((first_cluster - 2) * boot_sect->sect_per_cluster), NULL);
+            break;
+        }
+    }
+
+    return addr;
+}

M src/kernel/main.c → src/kernel/main.c

@@ -18,6 +18,7 @@ #include "cedos/fat.h"
 
 #include "linker.h"
 #include "assert.h"
+#include "string.h"
 
 int os_init(void) {
     core_init();
@@ -168,17 +169,16 @@ }
         printk("\n");
     }
 
-    while (1) {}
-
     // create test tasks
     printk("Creating tasks.\n");
     
     printk("Loading ELF executable.\n");
-    VIRT_ADDR addr = (uint32_t)(KERNEL_VMA) + (uint32_t)(0x8600 - (int)KERNEL_LMA);
-    printk("ELF address: %p\n", addr);
-    elf_exec(addr, 0x1000, "app1", "Hello World!");
-    elf_exec(addr, 0x1000, "app2", "Hello World!");
-    elf_exec(addr, 0x1000, "app3", "Hello World!");
+    VIRT_ADDR elf_addr = FAT_find_file("apps.o");
+    assert(elf_addr != (void*)(0));
+    printk("ELF address: %p\n", elf_addr);
+    elf_exec(elf_addr, 0x1000, "app1", "Hello World!");
+    elf_exec(elf_addr, 0x1000, "app2", "Hello World!");
+    elf_exec(elf_addr, 0x1000, "app3", "Hello World!");
  
     printk("Starting scheduler.\n");
     sched_start();

M src/kernel/string.c → src/kernel/string.c

@@ -34,4 +34,20 @@ unsigned int strlen (const char *str) {
     int i = 0;
     while (str[i]) { i++; }
     return i;
+}
+
+int strcmp(const char *str1, const char *str2) {
+    int i = 0;
+
+    while (1) {
+        if (str1[i] != str2[i]) {
+            return str1[i] - str2[i];
+        }
+
+        if (str1[i] == 0) {
+            return 0;
+        }
+
+        i++;
+    }
 }