Teach the kernel and the ELF trampoline how to boot from onboard flash.

svn path=/head/; revision=166819

sys/arm/arm/elf_trampoline.c

@@ -103,7 +103,7 @@ memcpy(void *dst, const void *src, int len)
     	char *d = dst;
 
 	while (len) {
-		if (len >= 4 && !((vm_offset_t)d & 3) &&
+		if (0 && len >= 4 && !((vm_offset_t)d & 3) &&
 		    !((vm_offset_t)s & 3)) {
 			*(uint32_t *)d = *(uint32_t *)s;
 			s += 4;
@@ -143,6 +143,37 @@ _start(void)
 	int physaddr = KERNPHYSADDR;
 	int tmp1;
 	unsigned int sp = ((unsigned int)&_end & ~3) + 4;
+#if defined(FLASHADDR) && defined(LOADERRAMADDR)
+	unsigned int pc;
+
+	__asm __volatile("adr %0, _start\n"
+	    : "=r" (pc));
+	if ((FLASHADDR > LOADERRAMADDR && pc >= FLASHADDR) ||
+	    (FLASHADDR < LOADERRAMADDR && pc < LOADERRAMADDR)) {
+		/*
+		 * We're running from flash, so just copy the whole thing
+		 * from flash to memory.
+		 * This is far from optimal, we could do the relocation or
+		 * the unzipping directly from flash to memory to avoid this
+		 * needless copy, but it would require to know the flash
+		 * physical address.
+		 */
+		unsigned int target_addr;
+		unsigned int tmp_sp;
+
+		target_addr = (unsigned int)&_start - PHYSADDR + LOADERRAMADDR;
+		tmp_sp = target_addr + 0x100000 +
+		    (unsigned int)&_end - (unsigned int)&_start;
+		memcpy((char *)target_addr, (char *)pc,
+		    (unsigned int)&_end - (unsigned int)&_start);
+		/* Temporary set the sp and jump to the new location. */
+		__asm __volatile(
+		    "mov sp, %1\n"
+		    "mov pc, %0\n"
+		    : : "r" (target_addr), "r" (tmp_sp));
+		
+	}
+#endif
 #ifdef KZIP
 	sp += KERNSIZE + 0x100;
 	sp &= ~(L1_TABLE_SIZE - 1);

sys/arm/arm/locore.S

@@ -66,47 +66,53 @@ __FBSDID("$FreeBSD$");
 ENTRY_NP(btext)
 
 ASENTRY_NP(_start)
-
+#if defined (FLASHADDR) && defined(LOADERRAMADDR)
-
+	/* Check if we're running from flash. */
-	/* Check if we are running on RAM, if not move ourself to RAM */
+	ldr	r7, =FLASHADDR
-#if 0
+	/* 
-	cmp	pc, #PHYSADDR
+	 * If we're running with MMU disabled, test against the
-	bhi	start_inram /* XXX: This is wrong */
+	 * physical address instead.
-#endif
-	b	start_inram /*
-			     * XXX: this is even more wrong, but RedBoot
-			     * use 0x00000000-0x100000000 as virtual
-			     * addresses for the RAM.
-			     */
-
-	/* move me to RAM
-	 * XXX: we can use memcpy if it is PIC
 	 */
-	ldr r1, Lcopy_size
+	mrc     p15, 0, r2, c1, c0, 0
-	adr r0, _C_LABEL(_start)
+	ands	r2, r2, #CPU_CONTROL_MMU_ENABLE
-	add r1, r1, #3
+	ldreq	r8, =PHYSADDR
-	mov r1, r1, LSR #2
+	ldrne	r8, =LOADERRAMADDR
-	mov r2, #PHYSADDR
+	cmp	r7, r8
-	add r2, r2, #0x00200000
+	bls 	flash_lower
-	mov r4, r2
+	cmp	r7, pc
-
+	bhi	from_ram
-5:	ldr r3,[r0],#4
+	b	do_copy
-	str r3,[r2],#4
+	
-	subs r1,r1,#1
+flash_lower:
-	bhi 5b
+	cmp	r8, pc
-
+	bls	from_ram
-	/* Jump to RAM */
+do_copy:
-	ldr r0, Lstart_off
+	ldr	r9, =KERNBASE
-	add pc, r4, r0
+	adr	r1, _start 
-
+	ldr	r0, Lreal_start
-Lcopy_size:	.word _edata-_C_LABEL(_start)
+	ldr	r2, Lend
-Lstart_off:	.word start_inram-_C_LABEL(_start)
+	sub	r2, r2, r0
-start_inram:
+	sub	r0, r0, r9
+	add	r0, r0, r8
+	mov	r4, r0
+	/* Make sure _arm_memcpy is NULL */
+	ldr	r3, .L_arm_memcpy
+	ldr	r3, [r3]
+	mov	r5, #0
+	str	r5, [r3]
+	bl	memcpy
+	ldr	r0, Lram_offset
+	add	pc, r4, r0
+Lram_offset:	.word from_ram-_C_LABEL(_start)
+from_ram:
+	nop
+#endif
 	adr	r7, Lunmapped
 	bic     r7, r7, #0xff000000
 	orr     r7, r7, #PHYSADDR
 			
 
+disable_mmu:
 	/* Disable MMU for a while */
 	mrc     p15, 0, r2, c1, c0, 0
 	bic	r2, r2, #(CPU_CONTROL_MMU_ENABLE | CPU_CONTROL_DC_ENABLE |\
@@ -120,7 +126,6 @@ start_inram:
 	nop
 	mov	pc, r7
 Lunmapped:
-
 #ifdef STARTUP_PAGETABLE_ADDR
 	/* build page table from scratch */
 	ldr	r0, Lstartup_pagetable
@@ -191,6 +196,10 @@ Lvirtaddr:
 	.word	KERNVIRTADDR
 Lphysaddr:
 	.word	KERNPHYSADDR
+Lreal_start:
+	.word	_start
+Lend:	
+	.word	_edata
 Lstartup_pagetable:
 	.word	STARTUP_PAGETABLE_ADDR
 mmu_init_table:
@@ -207,6 +216,11 @@ mmu_init_table:
 	.word	_end
 	.word	svcstk + INIT_ARM_STACK_SIZE
 
+#if defined(FLASHADDR) && defined(LOADERRAMADDR)
+.L_arm_memcpy:
+        .word   _C_LABEL(_arm_memcpy)
+#endif
+
 .Lvirt_done:
 	.word	virt_done
 .Lmainreturned: