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authorTitanMKD2012-06-10 11:44:36 +0200
committerTitanMKD2012-06-10 11:44:36 +0200
commit3c8e76f679158d2a5cb1a16a7da1c4f48066ddfc (patch)
tree0f8f4b8e95125113f8c37a81230159d7571c4a1d /lib
parentd2b15c72be1d3d3a85598cffce237bbae8401f9d (diff)
Added ROM to RAM code copy & exec with example of how to use it (miniblink_rom_to_ram).
Diffstat (limited to 'lib')
-rw-r--r--lib/lpc43xx/libopencm3_lpc43xx.ld4
-rw-r--r--lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld97
-rw-r--r--lib/lpc43xx/vector.c19
3 files changed, 120 insertions, 0 deletions
diff --git a/lib/lpc43xx/libopencm3_lpc43xx.ld b/lib/lpc43xx/libopencm3_lpc43xx.ld
index 5c3221b..47b403b 100644
--- a/lib/lpc43xx/libopencm3_lpc43xx.ld
+++ b/lib/lpc43xx/libopencm3_lpc43xx.ld
@@ -3,6 +3,7 @@
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
+ * Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
@@ -35,6 +36,7 @@ SECTIONS
.text : {
. = ALIGN(0x400);
+ _text_ram = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */
*(.vectors) /* Vector table */
*(.text*) /* Program code */
. = ALIGN(4);
@@ -50,6 +52,8 @@ SECTIONS
__exidx_end = .;
_etext = .;
+ _etext_ram = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */
+ _etext_rom = 0; /* Start of Code in RAM NULL because Copy of Code from ROM to RAM disabled */
. = ORIGIN(ram);
diff --git a/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld b/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld
new file mode 100644
index 0000000..f833aaf
--- /dev/null
+++ b/lib/lpc43xx/libopencm3_lpc43xx_rom_to_ram.ld
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
+ * Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Generic linker script for LPC43XX targets using libopencm3. */
+
+/* Memory regions must be defined in the ld script which includes this one. */
+
+/* Enforce emmition of the vector table. */
+EXTERN (vector_table)
+
+/* Define the entry point of the output file. */
+ENTRY(reset_handler)
+
+/* Define sections. */
+SECTIONS
+{
+ . = ORIGIN(rom);
+
+ .text : {
+ . = ALIGN(0x400);
+ _text_ram = . + ORIGIN(ram); /* Start of Code in RAM */
+
+ *(.vectors) /* Vector table */
+ *(.text*) /* Program code */
+ . = ALIGN(4);
+ *(.rodata*) /* Read-only data */
+ . = ALIGN(4);
+ } >rom
+
+ /* exception index - required due to libgcc.a issuing /0 exceptions */
+ __exidx_start = .;
+ .ARM.exidx : {
+ *(.ARM.exidx*)
+ } > rom
+ __exidx_end = .;
+
+ _etext = .;
+ _etext_ram = . + ORIGIN(ram);
+ _etext_rom = . + ORIGIN(rom_flash);
+
+ . = ORIGIN(ram);
+
+ .data : {
+ _data = .;
+ *(.data*) /* Read-write initialized data */
+ . = ALIGN(4);
+ _edata = .;
+ } >ram AT >rom
+
+ .bss : {
+ *(.bss*) /* Read-write zero initialized data */
+ *(COMMON)
+ . = ALIGN(4);
+ _ebss = .;
+ } >ram
+
+ /* exception unwind data - required due to libgcc.a issuing /0 exceptions */
+ .ARM.extab : {
+ *(.ARM.extab*)
+ } >ram
+
+ /*
+ * The .eh_frame section appears to be used for C++ exception handling.
+ * You may need to fix this if you're using C++.
+ */
+ /DISCARD/ : { *(.eh_frame) }
+
+ /*
+ * Another section used by C++ stuff, appears when using newlib with
+ * 64bit (long long) printf support - discard it for now.
+ */
+ /DISCARD/ : { *(.ARM.exidx) }
+
+ end = .;
+
+ /* Leave room above stack for IAP to run. */
+ __StackTop = ORIGIN(ram) + LENGTH(ram) - 32;
+ PROVIDE(_stack = __StackTop);
+}
diff --git a/lib/lpc43xx/vector.c b/lib/lpc43xx/vector.c
index 33eee4a..631e54e 100644
--- a/lib/lpc43xx/vector.c
+++ b/lib/lpc43xx/vector.c
@@ -22,6 +22,7 @@
/* Symbols exported by the linker script(s). */
extern unsigned _etext, _data, _edata, _ebss, _stack;
+extern unsigned _etext_ram, _text_ram, _etext_rom;
void main(void);
void reset_handler(void);
@@ -158,11 +159,29 @@ void (*const vector_table[]) (void) = {
qei_irqhandler,
};
+#define MMIO32(addr) (*(volatile unsigned long*)(addr))
+#define CREG_M4MEMMAP MMIO32( (0x40043000 + 0x100) )
+
void reset_handler(void)
{
volatile unsigned *src, *dest;
__asm__("MSR msp, %0" : : "r"(&_stack));
+ /* Copy the code from ROM to Real RAM (if enabled) */
+ if( (&_etext_ram-&_text_ram) > 0 )
+ {
+ src = &_etext_rom-(&_etext_ram-&_text_ram);
+ for(dest = &_text_ram; dest < &_etext_ram; )
+ {
+ *dest++ = *src++;
+ }
+
+ /* Change Shadow memory to Real RAM */
+ CREG_M4MEMMAP = (unsigned long)&_text_ram;
+
+ /* Continue Execution in RAM */
+ }
+
for (src = &_etext, dest = &_data; dest < &_edata; src++, dest++)
*dest = *src;