Merge git://git.denx.de/u-boot-mips

9 files changed, 237 insertions, 182 deletions

diff --git a/arch/mips/Makefile.postlink b/arch/mips/Makefile.postlink
new file mode 100644
index 00000000000..7da3acdf52f
--- /dev/null
+++ b/arch/mips/Makefile.postlink
@@ -0,0 +1,23 @@
+#
+# Copyright (c) 2017 Imagination Technologies Ltd.
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+PHONY := __archpost
+__archpost:
+
+-include include/config/auto.conf
+include scripts/Kbuild.include
+
+CMD_RELOCS = tools/mips-relocs
+quiet_cmd_relocs = RELOCS  $@
+      cmd_relocs = $(CMD_RELOCS) $@
+
+u-boot: FORCE
+	@true
+	$(call if_changed,relocs)
+
+.PHONY: FORCE
+
+FORCE:
diff --git a/arch/mips/config.mk b/arch/mips/config.mk
index 2c72c1553d6..cefdbe65e11 100644
--- a/arch/mips/config.mk
+++ b/arch/mips/config.mk
@@ -56,25 +56,14 @@ PLATFORM_ELFFLAGS += -B mips $(OBJCOPYFLAGS)
 # LDFLAGS_vmlinux		+= -G 0 -static -n -nostdlib
 # MODFLAGS			+= -mlong-calls
 #
-# On the other hand, we want PIC in the U-Boot code to relocate it from ROM
-# to RAM. $28 is always used as gp.
-#
-ifdef CONFIG_SPL_BUILD
-PF_ABICALLS			:= -mno-abicalls
-PF_PIC				:= -fno-pic
-PF_PIE				:=
-else
-PF_ABICALLS			:= -mabicalls
-PF_PIC				:= -fpic
-PF_PIE				:= -pie
-PF_OBJCOPY			:= -j .got -j .rel.dyn -j .padding
-PF_OBJCOPY			+= -j .dtb.init.rodata
+ifndef CONFIG_SPL_BUILD
+OBJCOPYFLAGS			+= -j .got -j .rel -j .padding -j .dtb.init.rodata
+LDFLAGS_FINAL			+= --emit-relocs
 endif
 
-PLATFORM_CPPFLAGS		+= -G 0 $(PF_ABICALLS) $(PF_PIC)
+PLATFORM_CPPFLAGS		+= -G 0 -mno-abicalls -fno-pic
 PLATFORM_CPPFLAGS		+= -msoft-float
 PLATFORM_LDFLAGS		+= -G 0 -static -n -nostdlib
 PLATFORM_RELFLAGS		+= -ffunction-sections -fdata-sections
-LDFLAGS_FINAL			+= --gc-sections $(PF_PIE)
+LDFLAGS_FINAL			+= --gc-sections
 OBJCOPYFLAGS			+= -j .text -j .rodata -j .data -j .u_boot_list
-OBJCOPYFLAGS			+= $(PF_OBJCOPY)
diff --git a/arch/mips/cpu/start.S b/arch/mips/cpu/start.S
index d01ee9f9bdd..952c57afd71 100644
--- a/arch/mips/cpu/start.S
+++ b/arch/mips/cpu/start.S
@@ -221,18 +221,6 @@ wr_done:
 	ehb
 #endif
 
-	/*
-	 * Initialize $gp, force pointer sized alignment of bal instruction to
-	 * forbid the compiler to put nop's between bal and _gp. This is
-	 * required to keep _gp and ra aligned to 8 byte.
-	 */
-	.align	PTRLOG
-	bal	1f
-	 nop
-	PTR	_gp
-1:
-	PTR_L	gp, 0(ra)
-
 #ifdef CONFIG_MIPS_CM
 	PTR_LA	t9, mips_cm_map
 	jalr	t9
@@ -291,121 +279,3 @@ wr_done:
 	 move	ra, zero
 
 	END(_start)
-
-/*
- * void relocate_code (addr_sp, gd, addr_moni)
- *
- * This "function" does not return, instead it continues in RAM
- * after relocating the monitor code.
- *
- * a0 = addr_sp
- * a1 = gd
- * a2 = destination address
- */
-ENTRY(relocate_code)
-	move	sp, a0			# set new stack pointer
-	move	fp, sp
-
-	move	s0, a1			# save gd in s0
-	move	s2, a2			# save destination address in s2
-
-	PTR_LI	t0, CONFIG_SYS_MONITOR_BASE
-	PTR_SUB	s1, s2, t0		# s1 <-- relocation offset
-
-	PTR_LA	t2, __image_copy_end
-	move	t1, a2
-
-	/*
-	 * t0 = source address
-	 * t1 = target address
-	 * t2 = source end address
-	 */
-1:
-	PTR_L	t3, 0(t0)
-	PTR_S	t3, 0(t1)
-	PTR_ADDU t0, PTRSIZE
-	blt	t0, t2, 1b
-	 PTR_ADDU t1, PTRSIZE
-
-	/*
-	 * Now we want to update GOT.
-	 *
-	 * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
-	 * generated by GNU ld. Skip these reserved entries from relocation.
-	 */
-	PTR_LA	t3, num_got_entries
-	PTR_LA	t8, _GLOBAL_OFFSET_TABLE_
-	PTR_ADD	t8, s1			# t8 now holds relocated _G_O_T_
-	PTR_ADDIU t8, t8, 2 * PTRSIZE	# skipping first two entries
-	PTR_LI	t2, 2
-1:
-	PTR_L	t1, 0(t8)
-	beqz	t1, 2f
-	 PTR_ADD t1, s1
-	PTR_S	t1, 0(t8)
-2:
-	PTR_ADDIU t2, 1
-	blt	t2, t3, 1b
-	 PTR_ADDIU t8, PTRSIZE
-
-	/* Update dynamic relocations */
-	PTR_LA	t1, __rel_dyn_start
-	PTR_LA	t2, __rel_dyn_end
-
-	b	2f			# skip first reserved entry
-	 PTR_ADDIU t1, 2 * PTRSIZE
-
-1:
-	lw	t8, -4(t1)		# t8 <-- relocation info
-
-	PTR_LI	t3, MIPS_RELOC
-	bne	t8, t3, 2f		# skip non-MIPS_RELOC entries
-	 nop
-
-	PTR_L	t3, -(2 * PTRSIZE)(t1)	# t3 <-- location to fix up in FLASH
-
-	PTR_L	t8, 0(t3)		# t8 <-- original pointer
-	PTR_ADD	t8, s1			# t8 <-- adjusted pointer
-
-	PTR_ADD	t3, s1			# t3 <-- location to fix up in RAM
-	PTR_S	t8, 0(t3)
-
-2:
-	blt	t1, t2, 1b
-	 PTR_ADDIU t1, 2 * PTRSIZE	# each rel.dyn entry is 2*PTRSIZE bytes
-
-	/*
-	 * Flush caches to ensure our newly modified instructions are visible
-	 * to the instruction cache. We're still running with the old GOT, so
-	 * apply the reloc offset to the start address.
-	 */
-	PTR_LA	a0, __text_start
-	PTR_LA	a1, __text_end
-	PTR_SUB	a1, a1, a0
-	PTR_LA	t9, flush_cache
-	jalr	t9
-	 PTR_ADD	a0, s1
-
-	PTR_ADD	gp, s1			# adjust gp
-
-	/*
-	 * Clear BSS
-	 *
-	 * GOT is now relocated. Thus __bss_start and __bss_end can be
-	 * accessed directly via $gp.
-	 */
-	PTR_LA	t1, __bss_start		# t1 <-- __bss_start
-	PTR_LA	t2, __bss_end		# t2 <-- __bss_end
-
-1:
-	PTR_S	zero, 0(t1)
-	blt	t1, t2, 1b
-	 PTR_ADDIU t1, PTRSIZE
-
-	move	a0, s0			# a0 <-- gd
-	move	a1, s2
-	PTR_LA	t9, board_init_r
-	jr	t9
-	 move	ra, zero
-
-	END(relocate_code)
diff --git a/arch/mips/cpu/u-boot.lds b/arch/mips/cpu/u-boot.lds
index 0129c996118..bd5536f0137 100644
--- a/arch/mips/cpu/u-boot.lds
+++ b/arch/mips/cpu/u-boot.lds
@@ -34,15 +34,6 @@ SECTIONS
 		*(.data*)
 	}
 
-	. = .;
-	_gp = ALIGN(16) + 0x7ff0;
-
-	.got : {
-		*(.got)
-	}
-
-	num_got_entries = SIZEOF(.got) >> PTR_COUNT_SHIFT;
-
 	. = ALIGN(4);
 	.sdata : {
 		*(.sdata*)
@@ -57,33 +48,19 @@ SECTIONS
 	__image_copy_end = .;
 	__init_end = .;
 
-	.rel.dyn : {
-		__rel_dyn_start = .;
-		*(.rel.dyn)
-		__rel_dyn_end = .;
-	}
-
-	.padding : {
-		/*
-		 * Workaround for a binutils feature (or bug?).
-		 *
-		 * The GNU ld from binutils puts the dynamic relocation
-		 * entries into the .rel.dyn section. Sometimes it
-		 * allocates more dynamic relocation entries than it needs
-		 * and the unused slots are set to R_MIPS_NONE entries.
-		 *
-		 * However the size of the .rel.dyn section in the ELF
-		 * section header does not cover the unused entries, so
-		 * objcopy removes those during stripping.
-		 *
-		 * Create a small section here to avoid that.
-		 */
-		LONG(0xFFFFFFFF)
+	/*
+	 * .rel must come last so that the mips-relocs tool can shrink
+	 * the section size & the PT_LOAD program header filesz.
+	 */
+	.rel : {
+		__rel_start = .;
+		BYTE(0x0)
+		. += (32 * 1024) - 1;
 	}
 
 	_end = .;
 
-	.bss __rel_dyn_start (OVERLAY) : {
+	.bss __rel_start (OVERLAY) : {
 		__bss_start = .;
 		*(.sbss.*)
 		*(.bss.*)
diff --git a/arch/mips/include/asm/relocs.h b/arch/mips/include/asm/relocs.h
new file mode 100644
index 00000000000..92e9d04f7cc
--- /dev/null
+++ b/arch/mips/include/asm/relocs.h
@@ -0,0 +1,24 @@
+/*
+ * MIPS Relocations
+ *
+ * Copyright (c) 2017 Imagination Technologies Ltd.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_MIPS_RELOCS_H__
+#define __ASM_MIPS_RELOCS_H__
+
+#define R_MIPS_NONE		0
+#define R_MIPS_32		2
+#define R_MIPS_26		4
+#define R_MIPS_HI16		5
+#define R_MIPS_LO16		6
+#define R_MIPS_PC16		10
+#define R_MIPS_64		18
+#define R_MIPS_HIGHER		28
+#define R_MIPS_HIGHEST		29
+#define R_MIPS_PC21_S2		60
+#define R_MIPS_PC26_S2		61
+
+#endif /* __ASM_MIPS_RELOCS_H__ */
diff --git a/arch/mips/include/asm/sections.h b/arch/mips/include/asm/sections.h
index fc4640a3928..b9d217999e2 100644
--- a/arch/mips/include/asm/sections.h
+++ b/arch/mips/include/asm/sections.h
@@ -8,4 +8,11 @@
 
 #include <asm-generic/sections.h>
 
+/**
+ * __rel_start: Relocation data generated by the mips-relocs tool
+ *
+ * See arch/mips/lib/reloc.c for details on the format & use of this data.
+ */
+extern uint8_t __rel_start[];
+
 #endif
diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index 659c6ad187c..ef557c69322 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -8,6 +8,7 @@
 obj-y	+= cache.o
 obj-y	+= cache_init.o
 obj-y	+= genex.o
+obj-y	+= reloc.o
 obj-y	+= stack.o
 obj-y	+= traps.o
 
diff --git a/arch/mips/lib/bootm.c b/arch/mips/lib/bootm.c
index be877625a8e..2b6790524c8 100644
--- a/arch/mips/lib/bootm.c
+++ b/arch/mips/lib/bootm.c
@@ -279,17 +279,17 @@ static void boot_prep_linux(bootm_headers_t *images)
 		boot_reloc_fdt(images);
 		boot_setup_fdt(images);
 	} else {
-		if (CONFIG_IS_ENABLED(CONFIG_MIPS_BOOT_ENV_LEGACY))
-			linux_env_legacy(images);
-
 		if (CONFIG_IS_ENABLED(MIPS_BOOT_CMDLINE_LEGACY)) {
 			linux_cmdline_legacy(images);
 
-			if (!CONFIG_IS_ENABLED(CONFIG_MIPS_BOOT_ENV_LEGACY))
+			if (!CONFIG_IS_ENABLED(MIPS_BOOT_ENV_LEGACY))
 				linux_cmdline_append(images);
 
 			linux_cmdline_dump();
 		}
+
+		if (CONFIG_IS_ENABLED(MIPS_BOOT_ENV_LEGACY))
+			linux_env_legacy(images);
 	}
 }
 
diff --git a/arch/mips/lib/reloc.c b/arch/mips/lib/reloc.c
new file mode 100644
index 00000000000..d0c52c9674f
--- /dev/null
+++ b/arch/mips/lib/reloc.c
@@ -0,0 +1,164 @@
+/*
+ * MIPS Relocation
+ *
+ * Copyright (c) 2017 Imagination Technologies Ltd.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ *
+ * Relocation data, found in the .rel section, is generated by the mips-relocs
+ * tool & contains a record of all locations in the U-Boot binary that need to
+ * be fixed up during relocation.
+ *
+ * The data is a sequence of unsigned integers, which are of somewhat arbitrary
+ * size. This is achieved by encoding integers as a sequence of bytes, each of
+ * which contains 7 bits of data with the most significant bit indicating
+ * whether any further bytes need to be read. The least significant bits of the
+ * integer are found in the first byte - ie. it somewhat resembles little
+ * endian.
+ *
+ * Each pair of two integers represents a relocation that must be applied. The
+ * first integer represents the type of relocation as a standard ELF relocation
+ * type (ie. R_MIPS_*). The second integer represents the offset at which to
+ * apply the relocation, relative to the previous relocation or for the first
+ * relocation the start of the relocated .text section.
+ *
+ * The end of the relocation data is indicated when type R_MIPS_NONE (0) is
+ * read, at which point no further integers should be read. That is, the
+ * terminating R_MIPS_NONE reloc includes no offset.
+ */
+
+#include <common.h>
+#include <asm/relocs.h>
+#include <asm/sections.h>
+
+/**
+ * read_uint() - Read an unsigned integer from the buffer
+ * @buf: pointer to a pointer to the reloc buffer
+ *
+ * Read one whole unsigned integer from the relocation data pointed to by @buf,
+ * advancing @buf past the bytes encoding the integer.
+ *
+ * Returns: the integer read from @buf
+ */
+static unsigned long read_uint(uint8_t **buf)
+{
+	unsigned long val = 0;
+	unsigned int shift = 0;
+	uint8_t new;
+
+	do {
+		new = *(*buf)++;
+		val |= (new & 0x7f) << shift;
+		shift += 7;
+	} while (new & 0x80);
+
+	return val;
+}
+
+/**
+ * apply_reloc() - Apply a single relocation
+ * @type: the type of reloc (R_MIPS_*)
+ * @addr: the address that the reloc should be applied to
+ * @off: the relocation offset, ie. number of bytes we're moving U-Boot by
+ *
+ * Apply a single relocation of type @type at @addr. This function is
+ * intentionally simple, and does the bare minimum needed to fixup the
+ * relocated U-Boot - in particular, it does not check for overflows.
+ */
+static void apply_reloc(unsigned int type, void *addr, long off)
+{
+	uint32_t u32;
+
+	switch (type) {
+	case R_MIPS_26:
+		u32 = *(uint32_t *)addr;
+		u32 = (u32 & GENMASK(31, 26)) |
+		      ((u32 + (off >> 2)) & GENMASK(25, 0));
+		*(uint32_t *)addr = u32;
+		break;
+
+	case R_MIPS_32:
+		*(uint32_t *)addr += off;
+		break;
+
+	case R_MIPS_64:
+		*(uint64_t *)addr += off;
+		break;
+
+	case R_MIPS_HI16:
+		*(uint32_t *)addr += off >> 16;
+		break;
+
+	default:
+		panic("Unhandled reloc type %u\n", type);
+	}
+}
+
+/**
+ * relocate_code() - Relocate U-Boot, generally from flash to DDR
+ * @start_addr_sp: new stack pointer
+ * @new_gd: pointer to relocated global data
+ * @relocaddr: the address to relocate to
+ *
+ * Relocate U-Boot from its current location (generally in flash) to a new one
+ * (generally in DDR). This function will copy the U-Boot binary & apply
+ * relocations as necessary, then jump to board_init_r in the new build of
+ * U-Boot. As such, this function does not return.
+ */
+void relocate_code(ulong start_addr_sp, gd_t *new_gd, ulong relocaddr)
+{
+	unsigned long addr, length, bss_len;
+	uint8_t *buf, *bss_start;
+	unsigned int type;
+	long off;
+
+	/*
+	 * Ensure that we're relocating by an offset which is a multiple of
+	 * 64KiB, ie. doesn't change the least significant 16 bits of any
+	 * addresses. This allows us to discard R_MIPS_LO16 relocs, saving
+	 * space in the U-Boot binary & complexity in handling them.
+	 */
+	off = relocaddr - (unsigned long)__text_start;
+	if (off & 0xffff)
+		panic("Mis-aligned relocation\n");
+
+	/* Copy U-Boot to RAM */
+	length = __image_copy_end - __text_start;
+	memcpy((void *)relocaddr, __text_start, length);
+
+	/* Now apply relocations to the copy in RAM */
+	buf = __rel_start;
+	addr = relocaddr;
+	while (true) {
+		type = read_uint(&buf);
+		if (type == R_MIPS_NONE)
+			break;
+
+		addr += read_uint(&buf) << 2;
+		apply_reloc(type, (void *)addr, off);
+	}
+
+	/* Ensure the icache is coherent */
+	flush_cache(relocaddr, length);
+
+	/* Clear the .bss section */
+	bss_start = (uint8_t *)((unsigned long)__bss_start + off);
+	bss_len = (unsigned long)&__bss_end - (unsigned long)__bss_start;
+	memset(bss_start, 0, bss_len);
+
+	/* Jump to the relocated U-Boot */
+	asm volatile(
+		       "move	$29, %0\n"
+		"	move	$4, %1\n"
+		"	move	$5, %2\n"
+		"	move	$31, $0\n"
+		"	jr	%3"
+		: /* no outputs */
+		: "r"(start_addr_sp),
+		  "r"(new_gd),
+		  "r"(relocaddr),
+		  "r"((unsigned long)board_init_r + off));
+
+	/* Since we jumped to the new U-Boot above, we won't get here */
+	unreachable();
+}