diff --git a/arch/arm/Makefile b/arch/arm/Makefile index b98d6b8..5125b87 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -181,6 +181,10 @@ LDFLAGS_barebox += -static --gc-sections endif +ifdef CONFIG_RELOCATABLE +LDFLAGS_barebox += -pie +endif + ifdef CONFIG_IMAGE_COMPRESSION KBUILD_BINARY := arch/arm/pbl/zbarebox.bin KBUILD_TARGET := zbarebox.bin diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile index 44410ee..5935e1c 100644 --- a/arch/arm/cpu/Makefile +++ b/arch/arm/cpu/Makefile @@ -21,3 +21,6 @@ obj-$(CONFIG_CACHE_L2X0) += cache-l2x0.o pbl-y += start-pbl.o setupc.o + +obj-y += common.o +pbl-y += common.o diff --git a/arch/arm/cpu/common.c b/arch/arm/cpu/common.c new file mode 100644 index 0000000..40f784f --- /dev/null +++ b/arch/arm/cpu/common.c @@ -0,0 +1,66 @@ +/* + * Copyright (c) 2010 Sascha Hauer , Pengutronix + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * relocate binary to the currently running address + */ +void relocate_to_current_adr(void) +{ + uint32_t offset; + uint32_t *dstart, *dend, *dynsym, *dynend; + + /* Get offset between linked address and runtime address */ + offset = get_runtime_offset(); + + dstart = (void *)(ld_var(__rel_dyn_start) - offset); + dend = (void *)(ld_var(__rel_dyn_end) - offset); + + dynsym = (void *)(ld_var(__dynsym_start) - offset); + dynend = (void *)(ld_var(__dynsym_end) - offset); + + while (dstart < dend) { + uint32_t *fixup = (uint32_t *)(*dstart - offset); + uint32_t type = *(dstart + 1); + + if ((type & 0xff) == 0x17) { + *fixup = *fixup - offset; + } else { + int index = type >> 8; + uint32_t r = dynsym[index * 4 + 1]; + + *fixup = *fixup + r - offset; + } + + *dstart -= offset; + dstart += 2; + } + + memset(dynsym, 0, (unsigned long)dynend - (unsigned long)dynsym); + + arm_early_mmu_cache_flush(); + flush_icache(); +} diff --git a/arch/arm/cpu/setupc.S b/arch/arm/cpu/setupc.S index d0de87d..7fd5d01 100644 --- a/arch/arm/cpu/setupc.S +++ b/arch/arm/cpu/setupc.S @@ -1,4 +1,5 @@ #include +#include .section .text.setupc @@ -35,3 +36,61 @@ pop {r4, r5} mov pc, lr ENDPROC(setup_c) + +#ifdef CONFIG_RELOCATABLE +/* + * void relocate_to_adr(unsigned long targetadr) + * + * Copy binary to targetadr, relocate code, clear bss and continue + * executing at new address. + */ +.section .text.relocate_to_adr +ENTRY(relocate_to_adr) + /* r0: target address */ + push {r3, r4, r5, r6, r7, r8} + mov r7, lr + + mov r6, r0 + + bl get_runtime_offset + + mov r5, r0 + + ld_var _text, r0, r4 + mov r8, r0 + + sub r1, r0, r5 /* r1: from address */ + + cmp r1, r6 /* already at correct address? */ + beq 1f /* yes, skip copy to new address */ + + ld_var __bss_start, r2, r4 + + sub r2, r2, r0 /* r2: size */ + mov r0, r6 /* r0: target */ + + add r7, r7, r0 /* adjust return address */ + sub r7, r7, r1 /* lr += offset */ + + bl memcpy /* copy binary */ + +#ifdef CONFIG_MMU + bl arm_early_mmu_cache_flush +#endif + mov r0,#0 + mcr p15, 0, r0, c7, c5, 0 /* flush icache */ + + ldr r0,=1f + sub r0, r0, r8 + add r0, r0, r6 + mov pc, r0 /* jump to relocated address */ +1: + bl relocate_to_current_adr /* relocate binary */ + + mov lr, r7 + + pop {r3, r4, r5, r6, r7, r8} + mov pc, lr + +ENDPROC(relocate_to_adr) +#endif diff --git a/arch/arm/cpu/start-pbl.c b/arch/arm/cpu/start-pbl.c index 91bc8fe..6f03c4a 100644 --- a/arch/arm/cpu/start-pbl.c +++ b/arch/arm/cpu/start-pbl.c @@ -55,9 +55,13 @@ uint32_t pg_start, pg_end, pg_len; void __noreturn (*barebox)(uint32_t, uint32_t, uint32_t); uint32_t endmem = membase + memsize; + unsigned long barebox_base; endmem -= STACK_SIZE; /* stack */ + if (IS_ENABLED(CONFIG_PBL_RELOCATABLE)) + relocate_to_current_adr(); + /* Get offset between linked address and runtime address */ offset = get_runtime_offset(); @@ -65,8 +69,13 @@ pg_end = (uint32_t)&input_data_end - offset; pg_len = pg_end - pg_start; + if (IS_ENABLED(CONFIG_RELOCATABLE)) + barebox_base = arm_barebox_image_place(membase + memsize); + else + barebox_base = TEXT_BASE; + if (offset && (IS_ENABLED(CONFIG_PBL_FORCE_PIGGYDATA_COPY) || - region_overlap(pg_start, pg_len, TEXT_BASE, pg_len * 4))) { + region_overlap(pg_start, pg_len, barebox_base, pg_len * 4))) { /* * copy piggydata binary to its link address */ @@ -86,14 +95,15 @@ free_mem_ptr = endmem; free_mem_end_ptr = free_mem_ptr + SZ_128K; - pbl_barebox_uncompress((void*)TEXT_BASE, (void *)pg_start, pg_len); + pbl_barebox_uncompress((void*)barebox_base, (void *)pg_start, pg_len); + arm_early_mmu_cache_flush(); flush_icache(); if (IS_ENABLED(CONFIG_THUMB2_BAREBOX)) - barebox = (void *)(TEXT_BASE + 1); + barebox = (void *)(barebox_base + 1); else - barebox = (void *)TEXT_BASE; + barebox = (void *)barebox_base; barebox(membase, memsize, boarddata); } diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c index cd34d9c..7c2bcd0 100644 --- a/arch/arm/cpu/start.c +++ b/arch/arm/cpu/start.c @@ -37,6 +37,11 @@ unsigned long endmem = membase + memsize; unsigned long malloc_start, malloc_end; + if (IS_ENABLED(CONFIG_RELOCATABLE)) { + unsigned long barebox_base = arm_barebox_image_place(endmem); + relocate_to_adr(barebox_base); + } + setup_c(); arm_stack_top = endmem; diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h index 11ef848..54da10a 100644 --- a/arch/arm/include/asm/barebox-arm.h +++ b/arch/arm/include/asm/barebox-arm.h @@ -26,6 +26,7 @@ #define _BAREBOX_ARM_H_ #include +#include /* cpu/.../cpu.c */ int cleanup_before_linux(void); @@ -40,6 +41,8 @@ uint32_t get_runtime_offset(void); void setup_c(void); +void relocate_to_current_adr(void); +void relocate_to_adr(unsigned long target); void __noreturn barebox_arm_entry(uint32_t membase, uint32_t memsize, uint32_t boarddata); #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_ARM_EXCEPTIONS) @@ -50,4 +53,27 @@ } #endif +/* + * For relocatable binaries find a suitable start address for the + * relocated binary. Beginning at the memory end substract the reserved + * space and round down a bit at the end. This is used by the pbl to + * extract the image to a suitable place so that the uncompressed image + * does not have to copy itself to another place. Also it's used by + * the uncompressed image to relocate itself to the same place. + */ +static inline unsigned long arm_barebox_image_place(unsigned long endmem) +{ + endmem -= STACK_SIZE; + endmem -= SZ_32K; /* ttb */ + endmem -= SZ_128K; /* early malloc */ + endmem -= SZ_1M; /* place for barebox image */ + + /* + * round down to make translating the objdump easier + */ + endmem &= ~(SZ_1M - 1); + + return endmem; +} + #endif /* _BAREBOX_ARM_H_ */ diff --git a/arch/arm/lib/barebox.lds.S b/arch/arm/lib/barebox.lds.S index e5aee8c..abdd69e 100644 --- a/arch/arm/lib/barebox.lds.S +++ b/arch/arm/lib/barebox.lds.S @@ -25,7 +25,11 @@ ENTRY(start) SECTIONS { +#ifdef CONFIG_RELOCATABLE + . = 0x0; +#else . = TEXT_BASE; +#endif #ifndef CONFIG_PBL_IMAGE PRE_IMAGE @@ -88,7 +92,20 @@ __usymtab : { BAREBOX_SYMS } __usymtab_end = .; + .rel.dyn : { + __rel_dyn_start = .; + *(.rel*) + __rel_dyn_end = .; + } + + .dynsym : { + __dynsym_start = .; + *(.dynsym) + __dynsym_end = .; + } + _edata = .; + . = ALIGN(4); __bss_start = .; .bss : { *(.bss*) } diff --git a/arch/arm/lib/runtime-offset.S b/arch/arm/lib/runtime-offset.S index aa56c7b..15bf414 100644 --- a/arch/arm/lib/runtime-offset.S +++ b/arch/arm/lib/runtime-offset.S @@ -35,6 +35,10 @@ .endm ld_var_entry _text +ld_var_entry __rel_dyn_start +ld_var_entry __rel_dyn_end +ld_var_entry __dynsym_start +ld_var_entry __dynsym_end ld_var_entry _barebox_image_size ld_var_entry __bss_start ld_var_entry __bss_stop diff --git a/arch/arm/pbl/Makefile b/arch/arm/pbl/Makefile index 6eeee73..3f50f77 100644 --- a/arch/arm/pbl/Makefile +++ b/arch/arm/pbl/Makefile @@ -23,6 +23,9 @@ PBL_CPPFLAGS += -fdata-sections -ffunction-sections LDFLAGS_zbarebox := -Map $(obj)/zbarebox.map LDFLAGS_zbarebox += -static --gc-sections +ifdef CONFIG_PBL_RELOCATABLE +LDFLAGS_zbarebox += -pie +endif zbarebox-common := $(barebox-pbl-common) $(obj)/$(piggy_o) zbarebox-lds := $(obj)/zbarebox.lds diff --git a/arch/arm/pbl/zbarebox.lds.S b/arch/arm/pbl/zbarebox.lds.S index 564b3c6..6b23bbe 100644 --- a/arch/arm/pbl/zbarebox.lds.S +++ b/arch/arm/pbl/zbarebox.lds.S @@ -29,7 +29,11 @@ ENTRY(pbl_start) SECTIONS { +#ifdef CONFIG_PBL_RELOCATABLE + . = 0x0; +#else . = TEXT_BASE - SZ_2M; +#endif PRE_IMAGE @@ -58,6 +62,18 @@ . = ALIGN(4); .data : { *(.data*) } + .rel.dyn : { + __rel_dyn_start = .; + *(.rel*) + __rel_dyn_end = .; + } + + .dynsym : { + __dynsym_start = .; + *(.dynsym) + __dynsym_end = .; + } + . = ALIGN(4); __bss_start = .; .bss : { *(.bss*) } diff --git a/common/Kconfig b/common/Kconfig index 3a55e01..92a6fdf 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -243,7 +243,7 @@ This is useful to print a nice backtrace when an exception occurs. config RELOCATABLE - depends on PPC + depends on PPC || ARM bool "generate relocatable barebox binary" help A non relocatable barebox binary will run at it's compiled in diff --git a/pbl/Kconfig b/pbl/Kconfig index 39752cc..5c7f62e 100644 --- a/pbl/Kconfig +++ b/pbl/Kconfig @@ -18,6 +18,16 @@ if PBL_IMAGE +config PBL_RELOCATABLE + depends on ARM + bool "relocatable pbl image" + help + Generate a pbl binary which can relocate itself during startup to run + on different addresses. This is useful if your memory layout is not + known during compile time. + This option only inflluences the PBL image. See RELOCATABLE to also make + the real image relocatable. + config IMAGE_COMPRESSION bool depends on HAVE_IMAGE_COMPRESSION