Add support for user information block reading. (Use IAP for writting)

diff --git a/core/user_information_block.c b/core/user_information_block.c
new file mode 100644 (file)
index 0000000..56a77e1
--- /dev/null
+++ b/core/user_information_block.c
@@ -0,0 +1,57 @@
+/****************************************************************************
+ *   core/user_information_block.c
+ *
+ *
+ *
+ * Copyright 2013-2014 Nathael Pajani <nathael.pajani@ed3l.fr>
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+
+/* The user information block is persistant flash memory block which can be programmed
+ *   and read by user code using IAP calls.
+ * It can provide the same functionnality as an EEPROM, though the reading access is
+ *   much more simple.
+ * Writting to the user flash is slightly more complicated though, mainly because flash
+ *   pages in the user information block are big 512 bytes blocks, much more than the
+ *   usual small eeprom pages.
+ * One must erase a full page before modifying data in it, thus reading it first to RAM,
+ *   modifying the RAM area, erasing the page, and then writting back.
+ * Reading/modify/write may be limited to the required size, but erase size will always
+ *   be a full page.
+ */
+
+/* The user information block of the LPC1224 has three 512 bytes pages. */
+
+/* Actually, the only purpose of this code is to return the address of the begining
+ *   of the user information block in flash, set by the linker from information in
+ *   the liker script (lpc_link_lpc1224.ld).
+*/
+
+#include <stdint.h>
+
+
+extern unsigned int _start_info;
+extern unsigned int _end_info;
+
+/* Get a pointer to the user information */
+void* get_user_info(void)
+{
+       return (void*)&_start_info;
+}
+
+

diff --git a/include/core/user_information_block.h b/include/core/user_information_block.h
new file mode 100644 (file)
index 0000000..705f478
--- /dev/null
+++ b/include/core/user_information_block.h
@@ -0,0 +1,42 @@
+/****************************************************************************
+ *   core/user_information_block.h
+ *
+ *
+ *
+ * Copyright 2013-2014 Nathael Pajani <nathael.pajani@ed3l.fr>
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+#ifndef USER_INFORMATION_BLOCK_H
+#define USER_INFORMATION_BLOCK_H
+
+#include <stdint.h>
+
+struct user_info {
+       char name[48];
+       uint32_t version;
+       uint32_t serial_number;
+       char user_info[8];
+} __attribute__ ((__packed__));
+
+
+/* Get a pointer to the begining address of the user information block in flash. */
+void* get_user_info(void);
+
+
+#endif /* USER_INFORMATION_BLOCK_H */
+

diff --git a/lpc_link_lpc1224.ld b/lpc_link_lpc1224.ld
index 9318ad2..16b01a2 100644 (file)
--- a/lpc_link_lpc1224.ld
+++ b/lpc_link_lpc1224.ld
@@ -6,11 +6,13 @@ MEMORY
 {
        sram (rwx) : ORIGIN = 0x10000000, LENGTH = 4k
        flash (rx) : ORIGIN = 0x00000000, LENGTH = 32k
+       info  (rx) : ORIGIN = 0x00040200, LENGTH = 1536
 }
 
 _sram_size = 4k;
 _sram_base = 0x10000000;
-_end_stack = (_sram_base + _sram_size);
+/* Leave 32 bytes for IAP functions, see UM10441 Chapter 20, section 20.8 */
+_end_stack = (_sram_base + _sram_size - 32);
 
 ENTRY(Reset_Handler)
 
@@ -49,6 +51,14 @@ SECTIONS {
                _end_bss = .;
        } >sram
 
+       . = ALIGN(4);
+
+       .user_information_block :
+       {
+               _start_info = .;
+               *(.user_information_block*)
+               _end_info = .;
+       } >info
 
        . = ALIGN(4);
 }