mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-15 01:17:39 +00:00
95 lines
2.6 KiB
Text
95 lines
2.6 KiB
Text
|
|
||
|
This document describes m[g]flash support in u-boot.
|
||
|
|
||
|
Contents
|
||
|
1. Overview
|
||
|
2. Porting mflash driver
|
||
|
3. Mflash command
|
||
|
4. Misc.
|
||
|
|
||
|
1. Overview
|
||
|
Mflash and gflash are embedded flash drive. The only difference is mflash is
|
||
|
MCP(Multi Chip Package) device. These two device operate exactly same way.
|
||
|
So the rest mflash repersents mflash and gflash altogether.
|
||
|
|
||
|
2. Porting mflash driver
|
||
|
|
||
|
2-1. Board configuration
|
||
|
* Mflash driver support
|
||
|
#define CONFIG_CMD_MG_DISK
|
||
|
#define CONFIG_LIBATA
|
||
|
|
||
|
* Environment variable support (optional)
|
||
|
#define CONFIG_ENV_IS_IN_MG_DISK
|
||
|
Also CONFIG_ENV_ADDR and CONFIG_ENV_SIZE should be defined.
|
||
|
CONFIG_ENV_ADDR is byte offset starting from 0.
|
||
|
|
||
|
Following example sets environment variable location to 0x80000 (1024'th
|
||
|
sector) and size of 0x400 (1024 byte)
|
||
|
#define CONFIG_ENV_ADDR 0x80000
|
||
|
#define CONFIG_ENV_SIZE 0x400
|
||
|
|
||
|
* Reserved size config (optional)
|
||
|
If you want to use some reserved area for bootloader, environment variable or
|
||
|
whatever, use CONFIG_MG_DISK_RES. The unit is KB. Mflash's block operation
|
||
|
method use this value as start offset. So any u-boot's partition table parser
|
||
|
and file system command work consistently. You can access this area by using
|
||
|
mflash command.
|
||
|
|
||
|
Following example sets 10MB of reserved area.
|
||
|
#define CONFIG_MG_DISK_RES 10240
|
||
|
|
||
|
2-2. Porting mg_get_drv_data function
|
||
|
Mflash is active device and need some gpio control for proper operation.
|
||
|
This board dependency resolved by using mg_get_drv_data function.
|
||
|
Port this function at your board init file. See include/mg_disk.h
|
||
|
|
||
|
Here is some pseudo example.
|
||
|
|
||
|
static void custom_hdrst_pin (u8 level)
|
||
|
{
|
||
|
if (level)
|
||
|
/* set hard reset pin to high */
|
||
|
else
|
||
|
/* set hard reset pin to low */
|
||
|
}
|
||
|
|
||
|
static void custom_ctrl_pin_init (void)
|
||
|
{
|
||
|
/* Set hard reset, write protect, deep power down pins
|
||
|
* to gpio.
|
||
|
* Set these pins to output high
|
||
|
*/
|
||
|
}
|
||
|
|
||
|
struct mg_drv_data* mg_get_drv_data (void)
|
||
|
{
|
||
|
static struct mg_drv_data prv;
|
||
|
|
||
|
prv.base = /* base address of mflash */
|
||
|
prv.mg_ctrl_pin_init = custom_ctrl_pin_init;
|
||
|
prv.mg_hdrst_pin = custom_hdrst_pin;
|
||
|
|
||
|
return &prv;
|
||
|
}
|
||
|
|
||
|
3. Mflash command
|
||
|
|
||
|
* initialize : mgd init
|
||
|
* random read : mgd read [from] [to] [size]
|
||
|
ex) read 256 bytes from 0x300000 of mflash to 0xA0100000 of host memory
|
||
|
mgd read 0x300000 0xA0100000 256
|
||
|
* random write : mgd write [from] [to] [size]
|
||
|
* sector read : mgd readsec [sector] [to] [count]
|
||
|
ex) read 10 sectors starts from 400 sector to 0xA0100000
|
||
|
mgd readsec 400 0xA0100000 10
|
||
|
* sector write : mgd writesec [from] [sector] [count]
|
||
|
|
||
|
4. Misc.
|
||
|
Mflash's device interface name for block driver is "mgd".
|
||
|
Here is ext2 file system access example.
|
||
|
|
||
|
mgd init
|
||
|
ext2ls mgd 0:1 /boot
|
||
|
ext2load mgd 0:1 0xa0010000 /boot/uImage 1954156
|