From 946234381d1d9d7a1cee773a233d328f90ac650e Mon Sep 17 00:00:00 2001
From: Byron Lathi <bslathi19@gmail.com>
Date: Tue, 5 Dec 2023 08:08:20 -0800
Subject: [PATCH] Look through files without trying too hard

---
 sw/kernel/filesystems/fat32.h   |  6 ++++--
 sw/kernel/filesystems/fat32.s   |  7 ++++++-
 sw/kernel/filesystems/fat32_c.c | 25 +++++++++++++++++++++----
 sw/test_code/fs_test/main.c     |  2 +-
 4 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/sw/kernel/filesystems/fat32.h b/sw/kernel/filesystems/fat32.h
index d938e00..fdaf57e 100644
--- a/sw/kernel/filesystems/fat32.h
+++ b/sw/kernel/filesystems/fat32.h
@@ -10,11 +10,13 @@ extern uint16_t fat_start_sector;
 extern uint32_t data_start_sector;
 extern uint32_t fat_size;
 extern uint8_t* sd_buf;
+extern uint8_t sectors_per_cluster;
 
 struct fat32_directory_entry {
     char file_name[8];
     char file_ext[3];
     uint8_t attr1;
+    uint8_t attr2;
     uint8_t create_time_10ms;
     uint16_t create_time;
     uint16_t create_date;
@@ -37,7 +39,7 @@ struct lfn_entry {
     uint16_t name_2[2];
 };
 
-uint8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dentry);
-uint8_t fat32_read_cluster(uint32_t cluster, void* buf);
+int8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dentry);
+int8_t fat32_read_cluster(uint32_t cluster, void* buf);
 
 #endif
diff --git a/sw/kernel/filesystems/fat32.s b/sw/kernel/filesystems/fat32.s
index 4349d0b..c30f2e5 100644
--- a/sw/kernel/filesystems/fat32.s
+++ b/sw/kernel/filesystems/fat32.s
@@ -9,7 +9,8 @@
 
 .export _fat32_init
 
-.export _root_cluster, _fat_start_sector, _data_start_sector, _fat_size, _sd_buf
+.export _root_cluster, _fat_start_sector, _data_start_sector
+.export _fat_size, _sd_buf, _sectors_per_cluster
 
 
 .data
@@ -17,6 +18,7 @@ _root_cluster: .res 4
 _fat_start_sector: .res 2
 _data_start_sector: .res 4
 _fat_size: .res 4
+_sectors_per_cluster: .res 1
 
 _sd_buf: .res 512
 
@@ -47,6 +49,9 @@ root_cluster_offs       = _sd_buf + $2C
     ldx #>ptr1
     jsr _SD_readSingleBlock
 
+    lda sectors_per_cluster
+    sta _sectors_per_cluster
+
     ldx #$00
 L1: lda root_cluster_offs,x
     sta _root_cluster,x
diff --git a/sw/kernel/filesystems/fat32_c.c b/sw/kernel/filesystems/fat32_c.c
index 4163141..64fa1c0 100644
--- a/sw/kernel/filesystems/fat32_c.c
+++ b/sw/kernel/filesystems/fat32_c.c
@@ -1,19 +1,23 @@
 #include "fat32.h"
+
 #include <devices/sd_card.h>
 #include <conio.h>
-
 #include <stdint.h>
+#include <string.h>
 
-uint8_t fat32_read_cluster(uint32_t cluster, void* buf) {
+int8_t fat32_read_cluster(uint32_t cluster, void* buf) {
     uint8_t error;
     uint32_t addr = (cluster - 2) + data_start_sector;
     SD_readSingleBlock(addr, buf, &error);
     return error;
 }
 
-uint8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dentry) {
+int8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dentry) {
     struct fat32_directory_entry* local_entry;
     int i = 0;
+
+    cprintf("Sectors per cluster: %hhx\n", sectors_per_cluster);
+
     fat32_read_cluster(root_cluster, sd_buf);
     for (i = 0; i < 16; i++){
         local_entry = sd_buf + i*32;
@@ -21,6 +25,19 @@ uint8_t fat32_get_cluster_by_name(char* name, struct fat32_directory_entry* dent
             continue;
         }
         cprintf("Name: %.11s\n", local_entry->file_name, local_entry->file_ext);
-        cprintf("attr1: %x\n", local_entry->attr1);
+        if (!strncmp(local_entry->file_name, name, 11)) {
+            i = -1;
+            break;
+        }
     }
+    if (i != -1) {
+        cprintf("Failed to find file.\n");
+        return -1;
+    }
+
+    cprintf("Found file!\n");
+
+    cprintf("attr1: %x\n", local_entry->attr1);
+    cprintf("cluster: %x %x\n", local_entry->cluster_high, local_entry->cluster_low);
+    cprintf("File Size: %lx\n", local_entry->file_size);
 }
diff --git a/sw/test_code/fs_test/main.c b/sw/test_code/fs_test/main.c
index f0ecc4e..7b4df75 100644
--- a/sw/test_code/fs_test/main.c
+++ b/sw/test_code/fs_test/main.c
@@ -6,6 +6,6 @@ void fat32_init(void);
 int main(void) {
     struct fat32_directory_entry dentry;
     fat32_init();
-    fat32_get_cluster_by_name("KERNEL  O65", &dentry);
+    fat32_get_cluster_by_name("TEST    TXT", &dentry);
     return 0;
 }
\ No newline at end of file