Celina's Git — CeDOS: 7cc0b6229bb9bb3ed26fe2fb3da13e647c4de222

Moved kernel back to 0x100000 to allow for bigger ramdisk in the future (and to avoid collision with VGA memory)

Celina Kalus

hello@celinakalus.de

Sat, 18 Mar 2023 22:36:42 +0100

commit 7cc0b6229bb9bb3ed26fe2fb3da13e647c4de222

parent 5707f8191eec3eec067863a43df4e6bb078b626a

3 files changed, 19 insertions(+), 2 deletions(-)

jump to

src/boot/fat.c

src/boot/fat.h

src/boot/paging.c

A src/boot/fat.c

A src/boot/fat.h

@@ -0,0 +1,17 @@
+#ifndef FAT_H
+#define FAT_H
+
+#include <stdint.h>
+
+typedef struct {
+    char jmp[3];
+    char oemname[8];
+
+    uint16_t bytes_per_sect;
+    uint8_t sect_per_cluster;
+    uint16_t num_reserved_sectors;
+    uint8_t num_FAT;
+    uint16_t max_root_dir_entries;
+} BOOT_SECT;
+
+#endif

M src/boot/paging.c → src/boot/paging.c

@@ -10,7 +10,7 @@ }
 
 void ss_copy() {
     char *src = (char*)(0x14E00);
-    char *dest = (char*)(0x40000);
+    char *dest = (char*)(0x100000);
     int num = 0x80 * 0x200;
 
     for (uint32_t i = 0; i < num; i++) {
@@ -33,7 +33,7 @@ // map 4M of kernel to 0xC0000000
     (*pdir)[PAGE_DIR_INDEX(0xC0000000)].entry = MAKE_PAGE_ENTRY(kernel, 0b000000000011);
 
     for (uint32_t i = 0; i < 1 << 10; i++) {
-        (*kernel)[i].entry = MAKE_PAGE_ENTRY(0x40000 + PAGE_SIZE * i, 0b000000000011);
+        (*kernel)[i].entry = MAKE_PAGE_ENTRY(0x100000 + PAGE_SIZE * i, 0b000000000011);
     }
 
     // identity map first 4M of memory