ramdisk

2 files changed, 36 insertions, 8 deletions

diff --git a/kernel/fs/fs.c b/kernel/fs/fs.c
index 01dea20..ef031f2 100644
--- a/kernel/fs/fs.c
+++ b/kernel/fs/fs.c
@@ -123,13 +123,16 @@ int fs_find_file_rel(struct file *rel, char *rel_path, struct file *res)
 static int disk_read_rd(struct disk *disk, size_t offset, size_t len,
 						uint8_t *buffer)
 {
-	if (offset + len >= disk->rd.len) {
+	if (offset >= disk->rd.len) {
 		WARN("attempted to read past length of ramdisk");
 		return -E_BAD_PARAM;
 	}
 
+	if (disk->rd.len - offset < len)
+		len = disk->rd.len - offset;
+
 	memcpy(buffer, disk->rd.start + offset, len);
-	return 0;
+	return len;
 }
 
 static int disk_read_ata(struct disk *disk, size_t offset, size_t len,
@@ -182,13 +185,16 @@ int disk_read(struct disk *disk, size_t offset, size_t len, void *buffer)
 static int disk_write_rd(struct disk *disk, size_t offset, size_t len,
 						 uint8_t *buffer)
 {
-	if (offset + len >= disk->rd.len) {
+	if (offset >= disk->rd.len) {
 		WARN("attempted to write past length of ramdisk");
 		return -E_BAD_PARAM;
 	}
 
+	if (disk->rd.len - offset < len)
+		len = disk->rd.len - offset;
+
 	memcpy(disk->rd.start + offset, buffer, len);
-	return 0;
+	return len;
 }
 
 static int disk_write_ata(struct disk *disk, size_t offset, size_t len,
diff --git a/kernel/mboot/module.c b/kernel/mboot/module.c
index 79d092e..cb05b45 100644
--- a/kernel/mboot/module.c
+++ b/kernel/mboot/module.c
@@ -1,3 +1,4 @@
+#include "comus/memory.h"
 #include <comus/mboot.h>
 
 #include "mboot.h"
@@ -12,13 +13,34 @@ struct multiboot_tag_module {
 	char cmdline[];
 };
 
+static void *mapped_addr = NULL;
+size_t initrd_len;
+
 void *mboot_get_initrd(size_t *len)
 {
-	void *tag = locate_mboot_table(MULTIBOOT_TAG_TYPE_MODULE);
+	struct multiboot_tag_module *mod;
+	void *tag, *phys;
+
+	// if already loaded, return
+	if (mapped_addr) {
+		*len = initrd_len;
+		return mapped_addr;
+	}
+
+	// locate
+	tag = locate_mboot_table(MULTIBOOT_TAG_TYPE_MODULE);
 	if (tag == NULL)
 		return NULL;
 
-	struct multiboot_tag_module *mod = (struct multiboot_tag_module *)tag;
-	*len = mod->mod_end - mod->mod_start;
-	return (void *)(uintptr_t)mod->mod_start;
+	mod = (struct multiboot_tag_module *)tag;
+	phys = (void *) (uintptr_t) mod->mod_start;
+	initrd_len = mod->mod_end - mod->mod_start;
+
+	// map addr
+	mapped_addr = kmapaddr(phys, NULL, initrd_len, F_PRESENT | F_WRITEABLE);
+	if (mapped_addr == NULL)
+		return NULL;
+
+	*len = initrd_len;
+	return mapped_addr;
 }