Commit 9a9d66f5 authored by Horatiu Vultur's avatar Horatiu Vultur Committed by Tom Rini

env: add spi_flash_read_env function

The spi_flash_read_env function is a wrapper over spi_flash_read, which
enables the env to read multiple flash page size from flash until '\0\0'
is read or the end of env partition is reached. Instead of reading the
entire env size. When it reads '\0\0', it stops reading further the env
and assumes that the rest of env is '\0'.

This is an optimization for large environments that contain few bytes
environment variables. In this case it doesn't need to read the entire
environment and only few pages.
Signed-off-by: default avatarHoratiu Vultur <horatiu.vultur@microchip.com>
parent a38c3af8
......@@ -81,6 +81,40 @@ static int setup_flash_device(void)
return 0;
}
static int is_end(const char *addr, size_t size)
{
/* The end of env variables is marked by '\0\0' */
int i = 0;
for (i = 0; i < size - 1; ++i)
if (addr[i] == 0x0 && addr[i + 1] == 0x0)
return 1;
return 0;
}
static int spi_flash_read_env(struct spi_flash *flash, u32 offset, size_t len,
void *buf)
{
u32 addr = 0;
u32 page_size = flash->page_size;
memset(buf, 0x0, len);
for (int i = 0; i < len / page_size; ++i) {
int ret = spi_flash_read(flash, offset, page_size,
&((char *)buf)[addr]);
if (ret < 0)
return ret;
if (is_end(&((char *)buf)[addr], page_size))
return 0;
addr += page_size;
offset += page_size;
}
return 0;
}
#if defined(CONFIG_ENV_OFFSET_REDUND)
#ifdef CMD_SAVEENV
static int env_sf_save(void)
......@@ -116,8 +150,8 @@ static int env_sf_save(void)
ret = -ENOMEM;
goto done;
}
ret = spi_flash_read(env_flash, saved_offset,
saved_size, saved_buffer);
ret = spi_flash_read_env(env_flash, saved_offset,
saved_size, saved_buffer);
if (ret)
goto done;
}
......@@ -183,10 +217,10 @@ static int env_sf_load(void)
if (ret)
goto out;
read1_fail = spi_flash_read(env_flash, CONFIG_ENV_OFFSET,
CONFIG_ENV_SIZE, tmp_env1);
read2_fail = spi_flash_read(env_flash, CONFIG_ENV_OFFSET_REDUND,
CONFIG_ENV_SIZE, tmp_env2);
read1_fail = spi_flash_read_env(env_flash, CONFIG_ENV_OFFSET,
CONFIG_ENV_SIZE, tmp_env1);
read2_fail = spi_flash_read_env(env_flash, CONFIG_ENV_OFFSET_REDUND,
CONFIG_ENV_SIZE, tmp_env2);
ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2,
read2_fail);
......@@ -220,8 +254,8 @@ static int env_sf_save(void)
if (!saved_buffer)
goto done;
ret = spi_flash_read(env_flash, saved_offset,
saved_size, saved_buffer);
ret = spi_flash_read_env(env_flash, saved_offset,
saved_size, saved_buffer);
if (ret)
goto done;
}
......@@ -277,10 +311,10 @@ static int env_sf_load(void)
if (ret)
goto out;
ret = spi_flash_read(env_flash,
CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE, buf);
ret = spi_flash_read_env(env_flash, CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE,
buf);
if (ret) {
set_default_env("spi_flash_read() failed", 0);
set_default_env("spi_flash_read_env() failed", 0);
goto err_read;
}
......
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