AArch32: Common changes needed for BL1/BL2

This patch adds common changes to support AArch32 state in
BL1 and BL2. Following are the changes:

* Added functions for disabling MMU from Secure state.
* Added AArch32 specific SMC function.
* Added semihosting support.
* Added reporting of unhandled exceptions.
* Added uniprocessor stack support.
* Added `el3_entrypoint_common` macro that can be
  shared by BL1 and BL32 (SP_MIN) BL stages. The
  `el3_entrypoint_common` is similar to the AArch64
  counterpart with the main difference in the assembly
  instructions and the registers that are relevant to
  AArch32 execution state.
* Enabled `LOAD_IMAGE_V2` flag in Makefile for
  `ARCH=aarch32` and added check to make sure that
  platform has not overridden to disable it.

Change-Id: I33c6d8dfefb2e5d142fdfd06a0f4a7332962e1a3

7 files changed, 311 insertions, 2 deletions

diff --git a/include/common/aarch32/asm_macros.S b/include/common/aarch32/asm_macros.S
index 11e45bbf..5f044991 100644
--- a/include/common/aarch32/asm_macros.S
+++ b/include/common/aarch32/asm_macros.S
@@ -70,6 +70,16 @@
 	.endm
 
 	/*
+	 * Declare the exception vector table, enforcing it is aligned on a
+	 * 32 byte boundary.
+	 */
+	.macro vector_base  label
+	.section .vectors, "ax"
+	.align 5
+	\label:
+	.endm
+
+	/*
 	 * This macro calculates the base address of the current CPU's multi
 	 * processor(MP) stack using the plat_my_core_pos() index, the name of
 	 * the stack storage and the size of each stack.
diff --git a/include/common/aarch32/el3_common_macros.S b/include/common/aarch32/el3_common_macros.S
new file mode 100644
index 00000000..a572ef99
--- /dev/null
+++ b/include/common/aarch32/el3_common_macros.S
@@ -0,0 +1,278 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __EL3_COMMON_MACROS_S__
+#define __EL3_COMMON_MACROS_S__
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <assert_macros.S>
+
+	/*
+	 * Helper macro to initialise EL3 registers we care about.
+	 */
+	.macro el3_arch_init_common _exception_vectors
+	/* ---------------------------------------------------------------------
+	 * Enable the instruction cache and alignment checks
+	 * ---------------------------------------------------------------------
+	 */
+	ldr	r1, =(SCTLR_RES1 | SCTLR_I_BIT | SCTLR_A_BIT)
+	ldcopr	r0, SCTLR
+	orr	r0, r0, r1
+	stcopr	r0, SCTLR
+	isb
+
+	/* ---------------------------------------------------------------------
+	 * Set the exception vectors (VBAR/MVBAR).
+	 * ---------------------------------------------------------------------
+	 */
+	ldr	r0, =\_exception_vectors
+	stcopr	r0, VBAR
+	stcopr	r0, MVBAR
+	isb
+
+	/* -----------------------------------------------------
+	 * Enable the SIF bit to disable instruction fetches
+	 * from Non-secure memory.
+	 * -----------------------------------------------------
+	 */
+	ldcopr	r0, SCR
+	orr	r0, r0, #SCR_SIF_BIT
+	stcopr	r0, SCR
+
+	/* -----------------------------------------------------
+	 * Enable the Asynchronous data abort now that the
+	 * exception vectors have been setup.
+	 * -----------------------------------------------------
+	 */
+	cpsie   a
+	isb
+
+	/* Enable access to Advanced SIMD registers */
+	ldcopr	r0, NSACR
+	bic	r0, r0, #NSASEDIS_BIT
+	bic	r0, r0, #NSTRCDIS_BIT
+	orr	r0, r0, #(NASCR_CP10_BIT | NASCR_CP11_BIT)
+	stcopr	r0, NSACR
+	isb
+
+	/*
+	 * Enable access to Advanced SIMD, Floating point and to the Trace
+	 * functionality as well.
+	 */
+	ldcopr	r0, CPACR
+	bic	r0, r0, #ASEDIS_BIT
+	bic	r0, r0, #TRCDIS_BIT
+	orr	r0, r0, #CPACR_ENABLE_FP_ACCESS
+	stcopr	r0, CPACR
+	isb
+
+	vmrs	r0, FPEXC
+	orr	r0, r0, #FPEXC_EN_BIT
+	vmsr	FPEXC, r0
+	isb
+	.endm
+
+/* -----------------------------------------------------------------------------
+ * This is the super set of actions that need to be performed during a cold boot
+ * or a warm boot in EL3. This code is shared by BL1 and BL32 (SP_MIN).
+ *
+ * This macro will always perform reset handling, architectural initialisations
+ * and stack setup. The rest of the actions are optional because they might not
+ * be needed, depending on the context in which this macro is called. This is
+ * why this macro is parameterised ; each parameter allows to enable/disable
+ * some actions.
+ *
+ *  _set_endian:
+ *	Whether the macro needs to configure the endianness of data accesses.
+ *
+ *  _warm_boot_mailbox:
+ *	Whether the macro needs to detect the type of boot (cold/warm). The
+ *	detection is based on the platform entrypoint address : if it is zero
+ *	then it is a cold boot, otherwise it is a warm boot. In the latter case,
+ *	this macro jumps on the platform entrypoint address.
+ *
+ *  _secondary_cold_boot:
+ *	Whether the macro needs to identify the CPU that is calling it: primary
+ *	CPU or secondary CPU. The primary CPU will be allowed to carry on with
+ *	the platform initialisations, while the secondaries will be put in a
+ *	platform-specific state in the meantime.
+ *
+ *	If the caller knows this macro will only be called by the primary CPU
+ *	then this parameter can be defined to 0 to skip this step.
+ *
+ * _init_memory:
+ *	Whether the macro needs to initialise the memory.
+ *
+ * _init_c_runtime:
+ *	Whether the macro needs to initialise the C runtime environment.
+ *
+ * _exception_vectors:
+ *	Address of the exception vectors to program in the VBAR_EL3 register.
+ * -----------------------------------------------------------------------------
+ */
+	.macro el3_entrypoint_common					\
+		_set_endian, _warm_boot_mailbox, _secondary_cold_boot,	\
+		_init_memory, _init_c_runtime, _exception_vectors
+
+	/* Make sure we are in Secure Mode */
+#if ASM_ASSERTION
+	ldcopr	r0, SCR
+	tst	r0, #SCR_NS_BIT
+	ASM_ASSERT(eq)
+#endif
+
+	.if \_set_endian
+		/* -------------------------------------------------------------
+		 * Set the CPU endianness before doing anything that might
+		 * involve memory reads or writes.
+		 * -------------------------------------------------------------
+		 */
+		ldcopr	r0, SCTLR
+		bic	r0, r0, #SCTLR_EE_BIT
+		stcopr	r0, SCTLR
+		isb
+	.endif /* _set_endian */
+
+	/* Switch to monitor mode */
+	cps	#MODE32_mon
+	isb
+
+	.if \_warm_boot_mailbox
+		/* -------------------------------------------------------------
+		 * This code will be executed for both warm and cold resets.
+		 * Now is the time to distinguish between the two.
+		 * Query the platform entrypoint address and if it is not zero
+		 * then it means it is a warm boot so jump to this address.
+		 * -------------------------------------------------------------
+		 */
+		bl	plat_get_my_entrypoint
+		cmp	r0, #0
+		bxne	r0
+	.endif /* _warm_boot_mailbox */
+
+	/* ---------------------------------------------------------------------
+	 * It is a cold boot.
+	 * Perform any processor specific actions upon reset e.g. cache, TLB
+	 * invalidations etc.
+	 * ---------------------------------------------------------------------
+	 */
+	bl	reset_handler
+
+	el3_arch_init_common \_exception_vectors
+
+	.if \_secondary_cold_boot
+		/* -------------------------------------------------------------
+		 * Check if this is a primary or secondary CPU cold boot.
+		 * The primary CPU will set up the platform while the
+		 * secondaries are placed in a platform-specific state until the
+		 * primary CPU performs the necessary actions to bring them out
+		 * of that state and allows entry into the OS.
+		 * -------------------------------------------------------------
+		 */
+		bl	plat_is_my_cpu_primary
+		cmp	r0, #0
+		bne	do_primary_cold_boot
+
+		/* This is a cold boot on a secondary CPU */
+		bl	plat_secondary_cold_boot_setup
+		/* plat_secondary_cold_boot_setup() is not supposed to return */
+		bl	plat_panic_handler
+
+	do_primary_cold_boot:
+	.endif /* _secondary_cold_boot */
+
+	/* ---------------------------------------------------------------------
+	 * Initialize memory now. Secondary CPU initialization won't get to this
+	 * point.
+	 * ---------------------------------------------------------------------
+	 */
+
+	.if \_init_memory
+		bl	platform_mem_init
+	.endif /* _init_memory */
+
+	/* ---------------------------------------------------------------------
+	 * Init C runtime environment:
+	 *   - Zero-initialise the NOBITS sections. There are 2 of them:
+	 *       - the .bss section;
+	 *       - the coherent memory section (if any).
+	 *   - Relocate the data section from ROM to RAM, if required.
+	 * ---------------------------------------------------------------------
+	 */
+	.if \_init_c_runtime
+#if IMAGE_BL32
+		/* -----------------------------------------------------------------
+		 * Invalidate the RW memory used by the BL32 (SP_MIN) image. This
+		 * includes the data and NOBITS sections. This is done to
+		 * safeguard against possible corruption of this memory by
+		 * dirty cache lines in a system cache as a result of use by
+		 * an earlier boot loader stage.
+		 * -----------------------------------------------------------------
+		 */
+		ldr	r0, =__RW_START__
+		ldr	r1, =__RW_END__
+		sub	r1, r1, r0
+		bl	inv_dcache_range
+#endif /* IMAGE_BL32 */
+
+		ldr	r0, =__BSS_START__
+		ldr	r1, =__BSS_SIZE__
+		bl	zeromem
+
+#if USE_COHERENT_MEM
+		ldr	r0, =__COHERENT_RAM_START__
+		ldr	r1, =__COHERENT_RAM_UNALIGNED_SIZE__
+		bl	zeromem
+#endif
+
+#if IMAGE_BL1
+		/* -----------------------------------------------------
+		 * Copy data from ROM to RAM.
+		 * -----------------------------------------------------
+		 */
+		ldr	r0, =__DATA_RAM_START__
+		ldr	r1, =__DATA_ROM_START__
+		ldr	r2, =__DATA_SIZE__
+		bl	memcpy
+#endif
+	.endif /* _init_c_runtime */
+
+	/* ---------------------------------------------------------------------
+	 * Allocate a stack whose memory will be marked as Normal-IS-WBWA when
+	 * the MMU is enabled. There is no risk of reading stale stack memory
+	 * after enabling the MMU as only the primary CPU is running at the
+	 * moment.
+	 * ---------------------------------------------------------------------
+	 */
+	bl	plat_set_my_stack
+	.endm
+
+#endif /* __EL3_COMMON_MACROS_S__ */
diff --git a/include/lib/aarch32/arch.h b/include/lib/aarch32/arch.h
index 6653cd14..aba15df1 100644
--- a/include/lib/aarch32/arch.h
+++ b/include/lib/aarch32/arch.h
@@ -191,6 +191,7 @@
 
 /* NASCR definitions */
 #define NSASEDIS_BIT		(1 << 15)
+#define NSTRCDIS_BIT		(1 << 20)
 #define NASCR_CP11_BIT		(1 << 11)
 #define NASCR_CP10_BIT		(1 << 10)
 
diff --git a/include/lib/aarch32/arch_helpers.h b/include/lib/aarch32/arch_helpers.h
index ddf660b1..3b4349c3 100644
--- a/include/lib/aarch32/arch_helpers.h
+++ b/include/lib/aarch32/arch_helpers.h
@@ -187,6 +187,9 @@ void flush_dcache_range(uintptr_t addr, size_t size);
 void clean_dcache_range(uintptr_t addr, size_t size);
 void inv_dcache_range(uintptr_t addr, size_t size);
 
+void disable_mmu_secure(void);
+void disable_mmu_icache_secure(void);
+
 DEFINE_SYSOP_FUNC(wfi)
 DEFINE_SYSOP_FUNC(wfe)
 DEFINE_SYSOP_FUNC(sev)
@@ -196,6 +199,9 @@ DEFINE_SYSOP_TYPE_FUNC(dsb, ish)
 DEFINE_SYSOP_TYPE_FUNC(dmb, ish)
 DEFINE_SYSOP_FUNC(isb)
 
+void __dead2 smc(uint32_t r0, uint32_t r1, uint32_t r2, uint32_t r3,
+		 uint32_t r4, uint32_t r5, uint32_t r6, uint32_t r7);
+
 DEFINE_SYSREG_RW_FUNCS(spsr)
 DEFINE_SYSREG_RW_FUNCS(cpsr)
 
@@ -289,4 +295,6 @@ DEFINE_DCOP_PARAM_FUNC(cvac, DCCMVAC)
 
 #define read_cntpct_el0()	read64_cntpct()
 
+#define read_ctr_el0()		read_ctr()
+
 #endif /* __ARCH_HELPERS_H__ */
diff --git a/include/lib/cpus/aarch32/cpu_macros.S b/include/lib/cpus/aarch32/cpu_macros.S
index f58f3e94..2b9947e3 100644
--- a/include/lib/cpus/aarch32/cpu_macros.S
+++ b/include/lib/cpus/aarch32/cpu_macros.S
@@ -42,12 +42,16 @@
 CPU_MIDR: /* cpu_ops midr */
 	.space  4
 /* Reset fn is needed during reset */
+#if IMAGE_BL1 || IMAGE_BL32
 CPU_RESET_FUNC: /* cpu_ops reset_func */
 	.space  4
+#endif
+#if IMAGE_BL32 /* The power down core and cluster is needed only in BL32 */
 CPU_PWR_DWN_CORE: /* cpu_ops core_pwr_dwn */
 	.space  4
 CPU_PWR_DWN_CLUSTER: /* cpu_ops cluster_pwr_dwn */
 	.space  4
+#endif
 CPU_OPS_SIZE = .
 
 	/*
@@ -60,13 +64,17 @@ CPU_OPS_SIZE = .
 	.align 2
 	.type cpu_ops_\_name, %object
 	.word \_midr
+#if IMAGE_BL1 || IMAGE_BL32
 	.if \_noresetfunc
 	.word 0
 	.else
 	.word \_name\()_reset_func
 	.endif
+#endif
+#if IMAGE_BL32
 	.word \_name\()_core_pwr_dwn
 	.word \_name\()_cluster_pwr_dwn
+#endif
 	.endm
 
 #endif /* __CPU_MACROS_S__ */
diff --git a/include/plat/common/common_def.h b/include/plat/common/common_def.h
index 7fef3392..e2c45138 100644
--- a/include/plat/common/common_def.h
+++ b/include/plat/common/common_def.h
@@ -41,9 +41,13 @@
 /*
  * Platform binary types for linking
  */
+#ifdef AARCH32
+#define PLATFORM_LINKER_FORMAT          "elf32-littlearm"
+#define PLATFORM_LINKER_ARCH            arm
+#else
 #define PLATFORM_LINKER_FORMAT          "elf64-littleaarch64"
 #define PLATFORM_LINKER_ARCH            aarch64
-
+#endif /* AARCH32 */
 
 /*
  * Generic platform constants
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index 852ccbcd..5b4d11df 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -86,7 +86,7 @@ uint32_t plat_interrupt_type_to_line(uint32_t type,
  * Optional common functions (may be overridden)
  ******************************************************************************/
 uintptr_t plat_get_my_stack(void);
-void plat_report_exception(unsigned long);
+void plat_report_exception(unsigned int exception_type);
 int plat_crash_console_init(void);
 int plat_crash_console_putc(int c);
 void plat_error_handler(int err) __dead2;