From 7b836064adef34e3dfb8ef7052abb446e9e03c0b Mon Sep 17 00:00:00 2001
From: Laurent Vivier <laurent@vivier.eu>
Date: Tue, 10 Nov 2015 00:11:48 +0100
Subject: [PATCH] libmap: add map_read_driver.c

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 libmap/Makefile          |  2 +-
 libmap/libmap.h          |  1 +
 libmap/map_read_driver.c | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 libmap/map_read_driver.c

diff --git a/libmap/Makefile b/libmap/Makefile
index faad91b..9370a43 100644
--- a/libmap/Makefile
+++ b/libmap/Makefile
@@ -30,7 +30,7 @@ SOURCES = map_bootblock_get_type.c map_bootblock_is_valid.c \
 	  map_set_bootinfo.c map_set_driver_info.c map_set_driver_number.c \
 	  map_set_partition_name.c map_set_partition_type.c map_set_startup.c \
 	  map_write.c map_block0_write.c map_read_sector.c map_checksum.c \
-	  map_write_sector.c map_get_blocksize.c map_init.c
+	  map_write_sector.c map_get_blocksize.c map_init.c map_read_driver.c
 
 HEADERS = libmap.h
 
diff --git a/libmap/libmap.h b/libmap/libmap.h
index ec8041b..2335288 100644
--- a/libmap/libmap.h
+++ b/libmap/libmap.h
@@ -186,4 +186,5 @@ extern int map_write_sector(map_t* map, off_t block, char *buffer, size_t nb);
 extern int map_get_blocksize(map_t *map);
 extern unsigned short map_checksum(unsigned char *addr, unsigned int length);
 extern unsigned short map_checksum_ATA(unsigned char *addr, unsigned int length);
+extern char *map_read_driver(map_t *map, int driver_number);
 #endif
diff --git a/libmap/map_read_driver.c b/libmap/map_read_driver.c
new file mode 100644
index 0000000..8013d45
--- /dev/null
+++ b/libmap/map_read_driver.c
@@ -0,0 +1,34 @@
+#include <stdlib.h>
+
+#include "libmap.h"
+
+char *map_read_driver(map_t *map, int driver_number)
+{
+	int block, size;
+	int blocksize;
+	char *driver;
+	int ret;
+
+	if (!map_is_valid(map))
+		return NULL;
+
+	blocksize = map_get_blocksize(map);
+
+	if (driver_number > map_get_driver_number(map))
+		return NULL;
+
+	block = read_long((u_int32_t*)&map->drivers.DrvInfo[driver_number].Block);
+	size = read_short((u_int16_t*)&map->drivers.DrvInfo[driver_number].Size);
+
+	driver = malloc(size * blocksize);
+	if (driver == NULL)
+		return NULL;
+
+	ret = map->device->read_sector(map->device->data, block, driver, size * blocksize);
+	if (ret == -1) {
+		free(driver);
+		driver = NULL;
+	}
+
+	return driver;
+}