u-boot/env/nvram.c
Simon Glass 4415f1d1f1 env: Create a location driver for each location
Set up a location driver for each supported environment location. At
present this just points to the global functions and is not used. A
later patch will switch this over to use private functions in each driver.

There are several special cases here in various drivers to handle
peculiarities of certain boards:

1. Some boards define CONFIG_ENV_IS_IN_FAT and CONFIG_SPL_ENV_SUPPORT but
do not actually load the environment in SPL. The env load code was
optimised out before but with the driver, it is not. Therefore a special
case is added to env/fat.c. The correct fix (depending on board testing
might be to disable CONFIG_SPL_ENV_SUPPORT.

2. A similar situations happens with CONFIG_ENV_IS_IN_FLASH. Some boards
do not actually load the environment in SPL, so to reduce code size we
need to drop that code. A similar fix may be possible with these boards,
or it may be possible to adjust the environment CONFIG settings.

Added to the above is that the CONFIG_SPL_ENV_SUPPORT option does not
apply when the environment is in flash.

Obviously the above has been discovered through painful and time-consuming
trial and error. Hopefully board maintainers can take a look and figure
out what is actually needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
2017-08-15 08:18:53 -04:00

125 lines
3.0 KiB
C

/*
* (C) Copyright 2000-2010
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Andreas Heppel <aheppel@sysgo.de>
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
*
* It might not be possible in all cases to use 'memcpy()' to copy
* the environment to NVRAM, as the NVRAM might not be mapped into
* the memory space. (I.e. this is the case for the BAB750). In those
* cases it might be possible to access the NVRAM using a different
* method. For example, the RTC on the BAB750 is accessible in IO
* space using its address and data registers. To enable usage of
* NVRAM in those cases I invented the functions 'nvram_read()' and
* 'nvram_write()', which will be activated upon the configuration
* #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
* strongly dependent on the used HW, and must be redefined for each
* board that wants to use them.
*/
#include <common.h>
#include <command.h>
#include <environment.h>
#include <linux/stddef.h>
#include <search.h>
#include <errno.h>
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
extern void *nvram_read(void *dest, const long src, size_t count);
extern void nvram_write(long dest, const void *src, size_t count);
env_t *env_ptr;
#else
env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
#endif
char *env_name_spec = "NVRAM";
#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
uchar env_get_char_spec(int index)
{
uchar c;
nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
return c;
}
#endif
void env_relocate_spec(void)
{
char buf[CONFIG_ENV_SIZE];
#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
#else
memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
#endif
env_import(buf, 1);
}
int saveenv(void)
{
env_t env_new;
int rcode = 0;
rcode = env_export(&env_new);
if (rcode)
return rcode;
#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
#else
if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
rcode = 1;
#endif
return rcode;
}
/*
* Initialize Environment use
*
* We are still running from ROM, so data use is limited
*/
int env_init(void)
{
#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
ulong crc;
uchar data[ENV_SIZE];
nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
if (crc32(0, data, ENV_SIZE) == crc) {
gd->env_addr = (ulong)CONFIG_ENV_ADDR + sizeof(long);
#else
if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
gd->env_addr = (ulong)&env_ptr->data;
#endif
gd->env_valid = ENV_VALID;
} else {
gd->env_addr = (ulong)&default_environment[0];
gd->env_valid = 0;
}
return 0;
}
U_BOOT_ENV_LOCATION(nvram) = {
.location = ENVL_NVRAM,
#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
.get_char = env_get_char_spec,
#endif
.load = env_relocate_spec,
.save = env_save_ptr(saveenv),
.init = env_init,
};