From 589b4aaf6adf3a60dd057c1100f30bd4e0d3ff2e Mon Sep 17 00:00:00 2001
From: Stefan `Sec` Zehl <sec@42.org>
Date: Sat, 21 May 2011 01:29:18 +0200
Subject: [PATCH] move reinvoke_isp to separate file, and fix it.

Note: Proto#1 badges need an small hardware patch %-)
---
 main.c         | 61 --------------------------------------------------
 reinvoke_isp.c | 52 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 61 deletions(-)
 create mode 100644 reinvoke_isp.c

diff --git a/main.c b/main.c
index e29d671..c0837e6 100644
--- a/main.c
+++ b/main.c
@@ -125,64 +125,3 @@ int main(void) {
     return 0;
 
 }
-
-/* This data must be global so it is not read from the stack */
-typedef void (*IAP)(uint32_t [], uint32_t []);
-IAP my_iap_entry = (IAP)0x1fff1ff1;
-uint32_t command[5], result[4];
-
-/* This function resets some microcontroller peripherals to reset
-   hardware configuration to ensure that the USB In-System Programming module
-   will work properly. It is normally called from reset and assumes some reset
-   configuration settings for the MCU.
-   Some of the peripheral configurations may be redundant in your specific
-   project.
-   */
-
-void ReinvokeISP(void) {
-	command[0] = 57;
-	/* Disable SYSTICK timer and interrupt before calling into ISP */
-	SYSTICK_STCTRL &= ~(SYSTICK_STCTRL_ENABLE | SYSTICK_STCTRL_TICKINT);
-	/* make sure USB clock is turned on before calling ISP */
-	SCB_SYSAHBCLKCTRL |= 0x04000;
-	/* make sure 32-bit Timer 1 is turned on before calling ISP */
-	SCB_SYSAHBCLKCTRL |= 0x00400;
-	/* make sure GPIO clock is turned on before calling ISP */
-	SCB_SYSAHBCLKCTRL |= 0x00040;
-	/* make sure IO configuration clock is turned on before calling ISP */
-	SCB_SYSAHBCLKCTRL |= 0x10000;
-	/* make sure AHB clock divider is 1:1 */
-	SCB_SYSAHBCLKDIV = 1;
-	/* Send Reinvoke ISP command to ISP entry point*/
-        gpioSetValue (CFG_LED_PORT, CFG_LED_PIN, CFG_LED_ON); 
-
-	/* Set stack pointer to ROM value (reset default) This must be the last
-	   piece of code executed before calling ISP, because most C expressions
-	   and function returns will fail after the stack pointer is changed. */
-
-	//__set_MSP(*((uint32_t *)0x1FFF0000)); /* inline asm function */
-
-	*((uint32_t *)(0x10000054)) = 0x0;
-
-	//set stack pointer
-	__asm("  ldr    r0, =%0\n"
-			"  mov    sp, r0\n"
-			:
-			:  "i" (0x1FFF0000));
-		
-
-
-	/* Enter ISP. We call "iap_entry" to enter ISP because the ISP entry is done
-	   through the same command interface as IAP. */
-	__asm(
-			"  ldr   r0, =0x39\n"
-			"  ldr   r1, =0x39\n"
-			"  ldr   r2, =0x39\n"
-			"  ldr   r3, =0x39\n"
-			" push {r3}\n"
-			"  ldr   r4,=0x1fff1ff1\n"
-			"  bx   r4\n"
-			);
-	//my_iap_entry(command, result);
-	// Not supposed to come back!
-}
diff --git a/reinvoke_isp.c b/reinvoke_isp.c
new file mode 100644
index 0000000..0d05fea
--- /dev/null
+++ b/reinvoke_isp.c
@@ -0,0 +1,52 @@
+#include "lpc134x.h"
+#include "sysdefs.h"
+
+/* Missing from core */
+
+#define set_MSP(x) \
+	__asm(  "msr   MSP, %0\n" : : "r" (x) )
+		
+
+/* Jump back into bootcode, enable mass storage firmware flashing */
+
+void ReinvokeISP(void) {
+	uint32_t command[5]; // 
+	command[0] = 57;
+
+	/* Disable SYSTICK timer and interrupt before calling into ISP */
+	SYSTICK_STCTRL &= ~(SYSTICK_STCTRL_ENABLE | SYSTICK_STCTRL_TICKINT);
+	/* make sure USB clock is turned on before calling ISP */
+	SCB_SYSAHBCLKCTRL |= 0x04000;
+	/* make sure 32-bit Timer 1 is turned on before calling ISP */
+	SCB_SYSAHBCLKCTRL |= 0x00400;
+	/* make sure GPIO clock is turned on before calling ISP */
+	SCB_SYSAHBCLKCTRL |= 0x00040;
+	/* make sure IO configuration clock is turned on before calling ISP */
+	SCB_SYSAHBCLKCTRL |= 0x10000;
+	/* make sure AHB clock divider is 1:1 */
+	SCB_SYSAHBCLKDIV = 1;
+
+	/* as per 19.2.1 of lpc13xx user manual, clear this byte of ram
+	   to avoid long delay before USB becomes active */
+	*((uint32_t *)(0x10000054)) = 0x0;
+
+	/* Set stack pointer to ROM value (reset default) This must be the last
+	   piece of code executed before calling ISP, because most C expressions
+	   and function returns will fail after the stack pointer is changed. */
+	set_MSP(*(int*)0x1FFF0000);
+
+	/* Enter ISP. We call "iap_entry" to enter ISP because the ISP entry is done
+	   through the same command interface as IAP. */
+	iap_entry(command, NULL);
+
+	/* Alternative shorter direct assembler way: */
+	/*
+	__asm(
+			"ldr  r0, =%0\n"
+			"ldr  lr, =0x1fff1ff1\n"
+			: : "i" (&command)
+			);
+	 */
+
+	/* NOTREACHED */
+}