Starting with writing docs ended with me fixing a critical bug

docs/modules.md

@@ -0,0 +1,14 @@
+#define MODULE_API_REGISTER 0
+#define MODULE_API_ADDFUNC 1
+#define MODULE_API_DELFUNC 2
+#define MODULE_API_ADDINT 3
+#define MODULE_API_DELINT 4
+#define MODULE_API_PRINT 5
+#define MODULE_API_READ 6 //read from virtual file
+#define MODULE_API_WRITE 7 //write to virtual file
+#define MODULE_API_CREAT 8 //create a virtual file and assigns it to the the proper module (requires having a read and write function passed)
+#define MODULE_API_DELET 9
+
+# Kimi's OS Kernel Module API
+
+On boot time, the bootloader will search the filesystem for the files `idm.elf` and `ifsm.elf` in the root directory. These are the only two modules loaded at boot time. Afterwards, the kernel will search the folder 

makefile

@@ -11,7 +11,7 @@ all: bootloader tools kernel
 	cp bin/bootloader.bin image.bin
 	qemu-img resize -f raw image.bin 512M
 	./diskwrite -v -l idm.elf ifsm.elf kernel.elf -o image.bin
-	# ./diskwrite -v idm.elf -o image.bin
+# 	./diskwrite -v -o image.bin
 	# ./diskwrite -v -l kernel.elf idm.elf -o image.bin
 	qemu-system-i386 -hda image.bin --no-reboot --no-shutdown -m 32m -smp 2 -serial mon:stdio -D intlog.txt -d int
 tools:
@@ -19,7 +19,16 @@ tools:
 
 bootloader:
 	$(AS) src/bootloader/main.s $(BL_ASFLAGS) -o bin/bootloader.bin
-
+run:
+	qemu-system-i386 -hda image.bin --no-reboot --no-shutdown -m 32m -smp 2 -serial mon:stdio -D intlog.txt -d int
+	
+test: bootloader tools kernel
+	cp bin/bootloader.bin image.bin
+	qemu-img resize -f raw image.bin 512M
+	./diskwrite -v -o image.bin
+	fsck.fat image.bin
+	sudo cp kernel.elf test/kernel.elf
+	make run
 # kernel: $(OBJS)
 kernel:
 	nasm src/kernel/entry.s -o bin/kernel/entry.o -f elf32

src/bootloader/main.s

@@ -61,13 +61,13 @@ fat_bpb:
         dd 1048576
 fat_ebpb32:
     .sectors_per_fat:
-        dd 1024
+        dd 2048
     .flags:
         dw 0
     .version:
         db 0, 1
     .root_dir_cluster:
-        dd 2 
+        dd 2
     .fs_info_sector:
         dw 1
     .backup_boot:
@@ -508,6 +508,7 @@ open_file:
     add si, ax
     xor cx, cx
     mov ax, [fat_ebpb32.root_dir_cluster]
+    sub ax, 2
     mov cl, [fat_bpb.sectors_per_cluster]
     mul cx
     add si, ax
@@ -562,11 +563,13 @@ read_file:
     ;args: esi = first cluster in chain
     ;edi = pointer to data
     push esi
+    sub esi, 2
     xor ecx, ecx
     xor edx, edx
     mov eax, esi
     mov cl, [fat_bpb.sectors_per_cluster]
     mul ecx; eax  = offset from file table
+    ; jmp $
 
     push eax
     xor eax, eax
@@ -895,7 +898,7 @@ fs_module_struct:
     .type: dd 2
     .flags: db 0
     .next_entry: dd 0
-kernel_file: db "kernel", 0, 0, "elf"
+kernel_file: db "kernel", 0x0, 0x0, "elf"
 disk_module_file: db "idm", 0, 0, 0, 0, 0, "elf"
 fs_module_file: db "ifsm", 0, 0, 0, 0, "elf"
 loaded_fat_block: dd 0

src/kernel/system/modules.h

@@ -3,12 +3,30 @@
 #include "../shared/kstdlib.h"
 
 #define MODULE_PRESENT 0x80
+//semver is represented by hexadecimal
+//first two digits are the major number
+//second two digits are the minor number
+//no patch number
+#define MODULE_API_VERSION 0x0100
+
+#define MODULE_API_REGISTER 0
+#define MODULE_API_ADDFUNC 1
+#define MODULE_API_DELFUNC 2
+#define MODULE_API_ADDINT 3
+#define MODULE_API_DELINT 4
+#define MODULE_API_PRINT 5
+#define MODULE_API_READ 6 //read from virtual file
+#define MODULE_API_WRITE 7 //write to virtual file
+#define MODULE_API_CREAT 8 //create a virtual file and assigns it to the the proper module (requires having a read and write function passed)
+#define MODULE_API_DELET 9
+
 
 typedef struct module{
     void *init_entry;
     uint32_t id;
     char name[16];
     uint8_t flags;
+    void (*fini)(void);
 }module_t;
 
 void init_modules(kernel_info_t *kernel_info);

src/kmodules/disk_driver.c

@@ -3,7 +3,7 @@
 
 KOS_MAPI_FP api;
 
-void init(KOS_MAPI_FP module_api){
+void init(KOS_MAPI_FP module_api, uint32_t api_version){
     uint16_t *t = (void *)0xb8000;
     *t = 0xf000;
     return;

src/kmodules/fs_driver.c

@@ -3,7 +3,7 @@
 
 KOS_MAPI_FP api;
 
-void init(KOS_MAPI_FP module_api){
+void init(KOS_MAPI_FP module_api, uint32_t api_version){
     uint16_t *t = (void *)0xb8002;
     *t = 0xf000;
     return;

src/kmodules/modlib.h

@@ -1 +1,9 @@
-typedef void (*KOS_MAPI_FP)(unsigned int function, ...);
+#pragma once
+#include <stdint.h>
+typedef void (*KOS_MAPI_FP)(unsigned int function, ...);
+typedef struct module{
+    void *init_entry;
+    uint32_t id;
+    char name[16];
+    uint8_t flags;
+}module_t;

tools/diskwrite.c

@@ -132,7 +132,7 @@ void write_cluster_value(fat_info *info, uint32_t value, uint32_t cluster){
 //read cluster - returns next cluster in chain
 uint32_t read_cluster(fat_info *info, uint32_t cluster, buffer_t buffer, size_t size, FILE *disk){
     // uint8_t *new_buffer = calloc(4096, 1 * (info->bpb.bytes_per_sector * info->bpb.sectors_per_cluster));
-    read_sector(disk, info->bpb.reserved_sectors + info->file_table_size_sectors + info->bpb.partition_start + (cluster * info->bpb.sectors_per_cluster), info->bpb.sectors_per_cluster, buffer);
+    read_sector(disk, info->bpb.reserved_sectors + info->file_table_size_sectors + info->bpb.partition_start + ((cluster - 2) * info->bpb.sectors_per_cluster), info->bpb.sectors_per_cluster, buffer);
     // memcpy(buffer, new_buffer, size);
     return info->file_table[cluster];
 }
@@ -154,7 +154,7 @@ int write_file(fat_info *info, file_t *file, buffer_t buffer, size_t size, FILE
     printf("start: %d count: %d\n", cluster, clusters);
     // return -1;
     for(uint32_t i = 0; i < clusters; i++){
-        write_sector(disk, info->bpb.reserved_sectors + info->file_table_size_sectors + info->bpb.partition_start + (cluster * info->bpb.sectors_per_cluster), info->bpb.sectors_per_cluster, new_buffer + i * info->bpb.sectors_per_cluster * info->bpb.bytes_per_sector);
+        write_sector(disk, info->bpb.reserved_sectors + info->file_table_size_sectors + info->bpb.partition_start + ((cluster - 2) * info->bpb.sectors_per_cluster), info->bpb.sectors_per_cluster, new_buffer + i * info->bpb.sectors_per_cluster * info->bpb.bytes_per_sector);
         uint32_t next_cluster = info->file_table[cluster];
         if(next_cluster == -1){
             next_cluster = find_free_cluster(info);
@@ -169,9 +169,9 @@ int write_file(fat_info *info, file_t *file, buffer_t buffer, size_t size, FILE
 }
 
 int create_file(char *path, fat_info *info, FILE *file, FILE *disk){
-    file_t *root_files = calloc(4096, sizeof(file_t));
+    file_t *root_files = calloc(info->bpb.sectors_per_cluster * 512, sizeof(file_t));
     // read_file(info, 0, (buffer_t)root_files, (uint32_t)4096, disk);
-    read_cluster(info, info->bpb.root_dir_cluster, (buffer_t)root_files, 4096, disk);
+    read_cluster(info, info->bpb.root_dir_cluster, (buffer_t)root_files, info->bpb.sectors_per_cluster * 512, disk);
     uint32_t index = 0;
     while(root_files[index].filename[0]){
         index++;
@@ -231,6 +231,8 @@ int detect_repair_fs(FILE *file, fat_info *info){
     info->file_table = calloc(info->bpb.sectors_per_fat * info->bpb.fat_count * info->bpb.bytes_per_sector, 1);
     read_sector(file, info->bpb.reserved_sectors, info->bpb.sectors_per_fat * info->bpb.fat_count, (buffer_t)info->file_table);
     if(!info->file_table[info->bpb.root_dir_cluster]){
+        info->file_table[0] = -1;
+        info->file_table[1] = -1;
         info->file_table[info->bpb.root_dir_cluster] = -1;
     }
 }
@@ -272,11 +274,11 @@ int main(int argc, char **argv){
         files[filec++] = argv[i];
         verbose && printf("IF: %s\n", argv[i]);
     }
-    if(filec == 0){
-        printf("Nothing to do, no files to write\n");
-        return 0;
-    }
     detect_repair_fs(output_file, &info);
+    // if(filec == 0){
+    //     printf("Nothing to do, no files to write\n");
+    //     return 0;
+    // }
     for(int i = 0; i < filec; i++){
         printf("\033[1;34mWriting file %d in list: %s\033[0m\n", i, files[i]);
         FILE *f = fopen(files[i], "r");
@@ -288,8 +290,8 @@ int main(int argc, char **argv){
         fclose(f);
     }
     if(list_root_dir){
-        buffer_t buf = calloc(4096, 1);
+        buffer_t buf = calloc(info.bpb.sectors_per_cluster * 512, 1);
-        read_cluster(&info, 2, buf, 4096, output_file);
+        read_cluster(&info, 2, buf, info.bpb.sectors_per_cluster * 512, output_file);
         file_t *root = (void *)buf;
         uint32_t index = 0;
         while(root[index].filename[0]){