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ruanhaishen
Nodemcu Firmware
Commits
5fa0a0bc
Commit
5fa0a0bc
authored
Feb 10, 2015
by
devsaurus
Browse files
cache pgm read data
parent
f2c881db
Changes
1
Hide whitespace changes
Inline
Side-by-side
app/modules/u8g.c
View file @
5fa0a0bc
...
...
@@ -25,15 +25,28 @@ static const u8g_fntpgm_uint8_t *font_array[] =
};
static
uint32_t
*
u8g_pgm_cached_iadr
=
NULL
;
static
uint32_t
u8g_pgm_cached_data
;
// function to read 4-byte aligned from program memory AKA irom0
u8g_pgm_uint8_t
u8g_pgm_read
(
const
u8g_pgm_uint8_t
*
adr
)
u8g_pgm_uint8_t
ICACHE_FLASH_ATTR
u8g_pgm_read
(
const
u8g_pgm_uint8_t
*
adr
)
{
uint32_t
iadr
=
(
uint32_t
)
adr
;
// set up pointer to 4-byte aligned memory location
uint32_t
*
ptr
=
(
uint32_t
*
)(
iadr
&
~
0x3
);
uint32_t
pgm_data
;
// read 4-byte aligned
uint32_t
pgm_data
=
*
ptr
;
if
(
ptr
==
u8g_pgm_cached_iadr
)
{
pgm_data
=
u8g_pgm_cached_data
;
}
else
{
// read 4-byte aligned
pgm_data
=
*
ptr
;
u8g_pgm_cached_iadr
=
ptr
;
u8g_pgm_cached_data
=
pgm_data
;
}
// return the correct byte within the retrieved 32bit word
return
pgm_data
>>
((
iadr
%
4
)
*
8
);
...
...
@@ -962,7 +975,7 @@ const LUA_REG_TYPE lu8g_map[] =
{
LNILKEY
,
LNILVAL
}
};
LUALIB_API
int
ICACHE_FLASH_ATTR
luaopen_u8g
(
lua_State
*
L
)
LUALIB_API
int
luaopen_u8g
(
lua_State
*
L
)
{
#if LUA_OPTIMIZE_MEMORY > 0
luaL_rometatable
(
L
,
"u8g.display"
,
(
void
*
)
lu8g_display_map
);
// create metatable
...
...
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