altos: Make stm-flash capable of switching to application

This shrinks the base OS load down a bit as well so that stm-flash
fits comfortably in the first 8kB of memory.

Signed-off-by: Keith Packard <keithp@keithp.com>

4 files changed, 202 insertions, 10 deletions

diff --git a/src/stm/altos-application.ld b/src/stm/altos-application.ld
new file mode 100644
index 00000000..63a3be00
--- /dev/null
+++ b/src/stm/altos-application.ld
@@ -0,0 +1,72 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+MEMORY {
+	rom (rx) : ORIGIN = 0x08002000, LENGTH = 120K
+	ram (!w) : ORIGIN = 0x20000000, LENGTH = 16K
+}
+
+INCLUDE registers.ld
+
+EXTERN (stm_interrupt_vector)
+
+SECTIONS {
+	/*
+	 * Rom contents
+	 */
+
+	.text ORIGIN(rom) : {
+		__text_start__ = .;
+		*(.interrupt)	/* Interrupt vectors */
+
+		. = ORIGIN(rom) + 0x100;
+
+		ao_romconfig.o(.romconfig*)
+		ao_product.o(.romconfig*)
+
+		*(.text*)	/* Executable code */
+		*(.rodata*)	/* Constants */
+
+	} > rom
+
+	.ARM.exidx : {
+		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
+		__text_end__ = .;
+	} > rom
+
+	/* Data -- relocated to RAM, but written to ROM
+	 */
+	.data ORIGIN(ram) : AT (ADDR(.ARM.exidx) + SIZEOF (.ARM.exidx)) {
+		__data_start__ = .;
+		*(.data)	/* initialized data */
+		__data_end__ = .;
+		__bss_start__ = .;
+	} >ram
+
+	.bss : {
+		*(.bss)
+		*(COMMON)
+		__bss_end__ = .;
+	} >ram
+
+	PROVIDE(__stack__ = ORIGIN(ram) + LENGTH(ram));
+	PROVIDE(end = .);
+}
+
+ENTRY(start);
+
+
diff --git a/src/stm/altos-loader.ld b/src/stm/altos-loader.ld
new file mode 100644
index 00000000..2d71b4ee
--- /dev/null
+++ b/src/stm/altos-loader.ld
@@ -0,0 +1,72 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+MEMORY {
+	rom (rx) : ORIGIN = 0x08000000, LENGTH = 8K
+	ram (!w) : ORIGIN = 0x20000000, LENGTH = 16K
+}
+
+INCLUDE registers.ld
+
+EXTERN (stm_interrupt_vector)
+
+SECTIONS {
+	/*
+	 * Rom contents
+	 */
+
+	.text ORIGIN(rom) : {
+		__text_start__ = .;
+		*(.interrupt)	/* Interrupt vectors */
+
+		. = ORIGIN(rom) + 0x100;
+
+		ao_romconfig.o(.romconfig*)
+		ao_product.o(.romconfig*)
+
+		*(.text*)	/* Executable code */
+		*(.rodata*)	/* Constants */
+
+	} > rom
+
+	.ARM.exidx : {
+		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
+		__text_end__ = .;
+	} > rom
+
+	/* Data -- relocated to RAM, but written to ROM
+	 */
+	.data ORIGIN(ram) : AT (ADDR(.ARM.exidx) + SIZEOF (.ARM.exidx)) {
+		__data_start__ = .;
+		*(.data)	/* initialized data */
+		__data_end__ = .;
+		__bss_start__ = .;
+	} >ram
+
+	.bss : {
+		*(.bss)
+		*(COMMON)
+		__bss_end__ = .;
+	} >ram
+
+	PROVIDE(__stack__ = ORIGIN(ram) + LENGTH(ram));
+	PROVIDE(end = .);
+}
+
+ENTRY(start);
+
+
diff --git a/src/stm/ao_boot.h b/src/stm/ao_boot.h
new file mode 100644
index 00000000..863d8e05
--- /dev/null
+++ b/src/stm/ao_boot.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_BOOT_H_
+#define _AO_BOOT_H_
+
+void
+ao_reboot_application(void);
+
+#endif /* _AO_BOOT_H_ */
diff --git a/src/stm/ao_interrupt.c b/src/stm/ao_interrupt.c
index 12763a30..9e756219 100644
--- a/src/stm/ao_interrupt.c
+++ b/src/stm/ao_interrupt.c
@@ -42,12 +42,45 @@ const void *stm_interrupt_vector[];
 
 #ifdef AO_BOOT_APPLICATION_PIN
 #include <ao_exti.h>
+
+#define AO_BOOT_APPLICATION		0x5a5aa5a5
+#define AO_BOOT_APPLICATION_CHECK	0xc3c33c3c
+
+static uint32_t	ao_boot_application;
+static uint32_t	ao_boot_application_check;
+
+static void
+ao_boot_chain(void) {
+	uint32_t	sp;
+	uint32_t	pc;
+
+	sp = BOOT_FETCH(0);
+	pc = BOOT_FETCH(4);
+	asm ("mov sp, %0" : : "r" (sp));
+	asm ("mov lr, %0" : : "r" (pc));
+	asm ("bx lr");
+}
+
+void
+ao_reboot_application(void)
+{
+	ao_boot_application = AO_BOOT_APPLICATION;
+	ao_boot_application_check = AO_BOOT_APPLICATION_CHECK;
+	ao_arch_reboot();
+}
+
 #endif
 
 void start(void) {
 #ifdef AO_BOOT_APPLICATION_PIN
 	uint16_t v;
 
+	if (ao_boot_application == AO_BOOT_APPLICATION &&
+	    ao_boot_application_check == AO_BOOT_APPLICATION_CHECK) {
+		ao_boot_application = 0;
+		ao_boot_application_check = 0;
+		ao_boot_chain();
+	}
 	/* Enable power interface clock */
 	stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
 	
@@ -63,16 +96,7 @@ void start(void) {
 	ao_disable_port(&AO_BOOT_APPLICATION_GPIO);
 	stm_rcc.apb1enr &= ~(1 << STM_RCC_APB1ENR_PWREN);
 	if (v == AO_BOOT_APPLICATION_VALUE)
-	{
-		uint32_t	sp;
-		uint32_t	pc;
-
-		sp = BOOT_FETCH(0);
-		pc = BOOT_FETCH(4);
-		asm ("mov sp, %0" : : "r" (sp));
-		asm ("mov lr, %0" : : "r" (pc));
-		asm ("bx lr");
-	}
+		ao_boot_chain();
 #endif
 
 	/* Set interrupt vector table offset */