Add support for romlib in the build system

Romlib is a new image that is stored in ROM and contains the code of
several libraries that can be shared between different images. All
the functions within in the library are accessed using a jump table
which allows to update the romlib image whithout changing the binary
compatibility. This jump table can be also stored in RAM and it can
allow to patch a romlib with potential bugs fixes..

Change-Id: If980ccdaca24b7aaca900e32acc68baf6f94ab35
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

7 files changed, 308 insertions, 0 deletions

diff --git a/lib/romlib/Makefile b/lib/romlib/Makefile
new file mode 100644
index 00000000..46b92068
--- /dev/null
+++ b/lib/romlib/Makefile
@@ -0,0 +1,71 @@
+#
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+AS          = $(CROSS_COMPILE)as
+LD          = $(CROSS_COMPILE)ld
+OC          = $(CROSS_COMPILE)objcopy
+CPP         = $(CROSS_COMPILE)cpp
+BUILD_DIR   = ../../$(BUILD_PLAT)/romlib
+LIB_DIR     = ../../$(BUILD_PLAT)/lib
+WRAPPER_DIR = ../../$(BUILD_PLAT)/libwrapper
+LIBS        = -lmbedtls -lfdt -lc
+INC         = $(INCLUDES:-I%=-I../../%)
+PPFLAGS     = $(INC) $(DEFINES) -P -D__ASSEMBLY__ -D__LINKER__ -MD -MP -MT $(BUILD_DIR)/romlib.ld
+OBJS        = $(BUILD_DIR)/jmptbl.o $(BUILD_DIR)/init.o
+
+V ?= 0
+ifeq ($(V),0)
+  Q := @
+else
+  Q :=
+endif
+
+ifeq ($(DEBUG),1)
+   CFLAGS  := -g
+   LDFLAGS := -g
+endif
+
+
+.PHONY: all clean distclean
+
+all: $(BUILD_DIR)/romlib.bin $(LIB_DIR)/libwrappers.a
+
+%.o: %.s
+	@echo "  AS      $@"
+	$(Q)$(AS) $(ASFLAGS) -o $@ $<
+
+$(BUILD_DIR)/%.o: %.s
+	@echo "  AS      $@"
+	$(Q)$(AS) $(ASFLAGS) -o $@ $<
+
+$(BUILD_DIR)/romlib.ld: romlib.ld.S
+	@echo "  PP      $@"
+	$(Q)$(CPP) $(PPFLAGS) -o $@ romlib.ld.S
+
+$(BUILD_DIR)/romlib.elf: $(OBJS) $(BUILD_DIR)/romlib.ld
+	@echo "  LD      $@"
+	$(Q)$(LD) -T $(BUILD_DIR)/romlib.ld -L$(LIB_DIR) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
+
+$(BUILD_DIR)/romlib.bin: $(BUILD_DIR)/romlib.elf
+	@echo "  BIN     $@"
+	$(Q)$(OC) -O binary $(BUILD_DIR)/romlib.elf $@
+
+$(WRAPPER_DIR)/jmpvar.s: $(BUILD_DIR)/romlib.elf
+	@echo "  VAR     $@"
+	$(Q)./genvar.sh -o $@ $(BUILD_DIR)/romlib.elf
+
+$(LIB_DIR)/libwrappers.a: jmptbl.i $(WRAPPER_DIR)/jmpvar.o
+	@echo "  AR      $@"
+	$(Q)./genwrappers.sh -b $(WRAPPER_DIR) -o $@ jmptbl.i
+
+$(BUILD_DIR)/jmptbl.s: jmptbl.i
+	@echo "  TBL     $@"
+	$(Q)./gentbl.sh -o $@ jmptbl.i
+
+clean:
+	@rm -f $(BUILD_DIR)/*
+
+-include $(BUILD_DIR)/romlib.d
diff --git a/lib/romlib/gentbl.sh b/lib/romlib/gentbl.sh
new file mode 100755
index 00000000..0695f6e4
--- /dev/null
+++ b/lib/romlib/gentbl.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+set -e
+
+output=jmptbl.s
+
+for i
+do
+	case $i in
+	-o)
+		output=$2
+		shift 2
+		;;
+	--)
+		shift
+		break
+		;;
+	-*)
+		echo usage: gentbl.sh [-o output]  file ... >&2
+		exit 1
+		;;
+	esac
+done
+
+tmp=`mktemp`
+trap "rm -f $tmp" EXIT INT QUIT
+
+rm -f $output
+
+awk -v OFS="\n" '
+BEGIN {print "\t.text",
+             "\t.globl\tjmptbl",
+             "jmptbl:"}
+      {sub(/[:blank:]*#.*/,"")}
+!/^$/ {print "\tb\t" $3}' "$@" > $tmp
+
+mv $tmp $output
diff --git a/lib/romlib/genvar.sh b/lib/romlib/genvar.sh
new file mode 100755
index 00000000..a3e2cdf6
--- /dev/null
+++ b/lib/romlib/genvar.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+set -e
+
+output=jmpvar.s
+for i
+do
+	case $i in
+	-o)
+		output=$2
+		shift 2
+		;;
+	--)
+		shift
+		break
+		;;
+	-*)
+		echo usage: genvar.sh [-o output] file... >&2
+		;;
+	esac
+done
+
+tmp=`mktemp`
+trap "rm -f $tmp" EXIT INT QUIT
+
+nm -a "$@" |
+awk -v OFS="\n" '
+$3 == ".text" {print "\t.data",
+                     "\t.globl\tjmptbl",
+                     "\t.align\t4",
+                     "jmptbl:\t.quad\t0x" $1}' > $tmp
+
+mv $tmp $output
diff --git a/lib/romlib/genwrappers.sh b/lib/romlib/genwrappers.sh
new file mode 100755
index 00000000..bcf670b9
--- /dev/null
+++ b/lib/romlib/genwrappers.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+set -e
+
+build=.
+out=output.a
+
+for i
+do
+	case $i in
+	-o)
+		out=$2
+		shift 2
+		;;
+	-b)
+		build=$2
+		shift 2
+		;;
+	--)
+		shift
+		break
+		;;
+	-*)
+		echo usage: genwrappers.sh [-o output] [-b dir] file ... >&2
+		exit 1
+		;;
+	esac
+done
+
+awk  '{sub(/[:blank:]*#.*/,"")}
+!/^$/ {print $1*4, $2, $3}' "$@" |
+while read idx lib sym
+do
+	file=$build/${lib}_$sym
+
+	cat <<EOF > $file.s
+	.globl	$sym
+$sym:
+	ldr	x17, =jmptbl
+	ldr	x17, [x17]
+	mov	x16, $idx
+	add	x16, x16, x17
+	br	x16
+EOF
+
+	${CROSS_COMPILE}as -o $file.o $file.s
+done
+
+${CROSS_COMPILE}ar -rc $out $build/*.o
diff --git a/lib/romlib/init.s b/lib/romlib/init.s
new file mode 100644
index 00000000..5cf2aca0
--- /dev/null
+++ b/lib/romlib/init.s
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+	.globl	rom_lib_init
+	.extern	__DATA_RAM_START__, __DATA_ROM_START__, __DATA_SIZE__
+	.extern	memset, memcpy
+
+rom_lib_init:
+	cmp	w0, #1
+	mov	w0, #0
+	b.le	1f
+	ret
+
+1:	stp	x29, x30, [sp, #-16]!
+	adrp	x0, __DATA_RAM_START__
+	ldr	x1,= __DATA_ROM_START__
+	ldr	x2, =__DATA_SIZE__
+	bl	memcpy
+
+	ldr	x0, =__BSS_START__
+	mov	x1, #0
+	ldr	x2, =__BSS_SIZE__
+	bl	memset
+	ldp	x29, x30, [sp], #16
+
+	mov	w0, #1
+	ret
diff --git a/lib/romlib/jmptbl.i b/lib/romlib/jmptbl.i
new file mode 100644
index 00000000..338cd8a7
--- /dev/null
+++ b/lib/romlib/jmptbl.i
@@ -0,0 +1,35 @@
+#
+# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+0	rom	rom_lib_init
+1	fdt	fdt_getprop_namelen
+2	fdt	fdt_setprop_inplace
+3	fdt	fdt_check_header
+4	fdt	fdt_node_offset_by_compatible
+5	mbedtls	mbedtls_asn1_get_alg
+6	mbedtls	mbedtls_asn1_get_alg_null
+7	mbedtls	mbedtls_asn1_get_bitstring_null
+8	mbedtls	mbedtls_asn1_get_bool
+9	mbedtls	mbedtls_asn1_get_int
+10	mbedtls	mbedtls_asn1_get_tag
+11	mbedtls	mbedtls_free
+12	mbedtls	mbedtls_md
+13	mbedtls	mbedtls_md_get_size
+14	mbedtls	mbedtls_memory_buffer_alloc_init
+15	mbedtls	mbedtls_oid_get_md_alg
+16	mbedtls	mbedtls_oid_get_numeric_string
+17	mbedtls	mbedtls_oid_get_pk_alg
+18	mbedtls	mbedtls_oid_get_sig_alg
+19	mbedtls	mbedtls_pk_free
+20	mbedtls	mbedtls_pk_init
+21	mbedtls	mbedtls_pk_parse_subpubkey
+22	mbedtls	mbedtls_pk_verify_ext
+23	mbedtls	mbedtls_platform_set_snprintf
+24	mbedtls	mbedtls_x509_get_rsassa_pss_params
+25	mbedtls	mbedtls_x509_get_sig_alg
+26	mbedtls	mbedtls_md_info_from_type
+27	c	exit
+28	c	atexit
diff --git a/lib/romlib/romlib.ld.S b/lib/romlib/romlib.ld.S
new file mode 100644
index 00000000..8f0bc62b
--- /dev/null
+++ b/lib/romlib/romlib.ld.S
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <platform_def.h>
+#include <xlat_tables_defs.h>
+
+MEMORY {
+	ROM (rx): ORIGIN = ROMLIB_RO_BASE, LENGTH = ROMLIB_RO_LIMIT - ROMLIB_RO_BASE
+	RAM (rwx): ORIGIN = ROMLIB_RW_BASE, LENGTH = ROMLIB_RW_END - ROMLIB_RW_BASE
+}
+
+OUTPUT_FORMAT(PLATFORM_LINKER_FORMAT)
+OUTPUT_ARCH(PLATFORM_LINKER_ARCH)
+ENTRY(jmptbl)
+
+SECTIONS
+{
+	. = ROMLIB_RO_BASE;
+	.text : {
+		*jmptbl.o(.text)
+		*(.text*)
+		*(.rodata*)
+	} >ROM
+
+	__DATA_ROM_START__ = LOADADDR(.data);
+
+	.data : {
+		__DATA_RAM_START__ = .;
+		*(.data*)
+		__DATA_RAM_END__ = .;
+	} >RAM AT>ROM
+
+	__DATA_SIZE__ = SIZEOF(.data);
+
+	.bss : {
+		__BSS_START__ = .;
+		*(.bss*)
+		__BSS_END__ = .;
+	 } >RAM
+	__BSS_SIZE__ = SIZEOF(.bss);
+}