minor changes in fat32

include/fat32/FAT32_SYS.nasm

@@ -126,11 +126,12 @@ FAT32_load_vbr:
 ; - fill fat32_bpb_t and compute derived fields
 ; - read FSInfo (free count/next free)
 ; - ???
-; int fat32_mount(uint32_t partition_lba, fat32_bpb_t* out);
+; int fat32_mount(FAT32_State_t* state, uint32_t partition_lba);
 FAT32_mountfs:
     __CDECL16_PROC_ENTRY
 .proc:
     ; mount: parse BPB, derive fat0_lba, data_lba, cluster0_lba.
+
 .endp:
     __CDECL16_PROC_EXIT
     ret
@@ -138,7 +139,7 @@ FAT32_mountfs:
     ERROR STEVIA_DEBUG_ERR
 
 
-; int fat32_read_fat(const fat32_bpb_t* v, uint32_t clus, uint32_t* out);
+; int fat32_read_fat(FAT32_State_t* state, uint32_t clus, uint32_t* out);
 FAT32_read_fat:
     __CDECL16_PROC_ENTRY
 .proc:
@@ -153,7 +154,7 @@ FAT32_read_fat:
 ;   EOC if (val & 0x0FFFFFFF) >= 0x0FFFFFF8.
 ;   bad if == 0x0FFFFFF7.
 ;   free if == 0x00000000.
-; int fat32_next_clus(const fat32_bpb_t* v, uint32_t clus, uint32_t* out_next);
+; int fat32_next_clus(FAT32_State_t* state, uint32_t clus, uint32_t* out_next);
 FAT32_next_cluster:
     __CDECL16_PROC_ENTRY
 .proc:
@@ -165,7 +166,7 @@ FAT32_next_cluster:
     ERROR STEVIA_DEBUG_ERR
 
 ; e.g:
-; uint64_t clus_to_lba(const fat32_bpb_t* v, uint32_t clus) {
+; uint64_t clus_to_lba(FAT32_State_t* state, uint32_t clus) {
 ;  return v->data_lba + (uint64_t)(clus - 2) * v->secs_per_clus;
 ; }
 FAT32_clus_to_lba:

include/fat32/fat32_structures.inc

@@ -195,20 +195,11 @@ endstruc
 
 ; 32 bytes
 struc FAT32_State_t
-    .first_data_sector_32     resd 1
-    .first_fat_sector_32      resd 1
-    .fat_size_32              resd 1
-    .curr_FAT_cluster_32      resd 1
-    .curr_dir_cluster_32      resd 1
-    .curr_drive_lba_32        resd 1
-endstruc
-
-; 16 bytes
-struc FAT32_NextClusterData_t
-    .fat_offset               resd 1
-    .fat_sector               resd 1
-    .entry_offset             resd 1
-    .reserved_1               resd 1
+    .u32_TotalClusters        resd 1
+    .u32_DataAreaStartSector  resd 1
+    .u32_FATAreaStartSector   resd 1
+    .p16_FATBuffer            resw 1
+    .p16_ClustBuffer          resw 1
 endstruc
 
 ; FAT32 Attributes

src/stage2/stage2.nasm

@@ -453,17 +453,19 @@ align 16, resb 1
 %define BIOSMemoryMap_SIZE 1024
 BIOSMemoryMap:
     resb BIOSMemoryMap_SIZE
-
-align 16, resb 1
-stack_bottom:
-    resb 2048
-stack_top:
 end_bss:
+; !!! End bss data !!!
+%define STACK_SIZE 0x1000       ; 4 KiB
 
 ; Pad to the cap (emits nothing in the file; only increases .bss virtual size).
 ; If BSS_SIZE > BSS_MAX_BYTES, this becomes negative and NASM errors out.
-%define BSS_MAX_BYTES 0x2000
+%define BSS_MAX_BYTES (0x2000 - STACK_SIZE)
 resb (BSS_MAX_BYTES - (end_bss - begin_bss))
 
+align 16, resb 1
+stack_bottom:
+    resb STACK_SIZE
+stack_top:
+
 ; Optional: keep a label for later math:
 bss_cap_end: