diff options
author | Denys Dmytriyenko <denis@denix.org> | 2009-03-17 14:32:59 -0400 |
---|---|---|
committer | Denys Dmytriyenko <denis@denix.org> | 2009-03-17 14:32:59 -0400 |
commit | 709c4d66e0b107ca606941b988bad717c0b45d9b (patch) | |
tree | 37ee08b1eb308f3b2b6426d5793545c38396b838 /recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch | |
parent | fa6cd5a3b993f16c27de4ff82b42684516d433ba (diff) |
rename packages/ to recipes/ per earlier agreement
See links below for more details:
http://thread.gmane.org/gmane.comp.handhelds.openembedded/21326
http://thread.gmane.org/gmane.comp.handhelds.openembedded/21816
Signed-off-by: Denys Dmytriyenko <denis@denix.org>
Acked-by: Mike Westerhof <mwester@dls.net>
Acked-by: Philip Balister <philip@balister.org>
Acked-by: Khem Raj <raj.khem@gmail.com>
Acked-by: Marcin Juszkiewicz <hrw@openembedded.org>
Acked-by: Koen Kooi <koen@openembedded.org>
Acked-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
Diffstat (limited to 'recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch')
-rw-r--r-- | recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch b/recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch new file mode 100644 index 0000000000..bc99f9a5db --- /dev/null +++ b/recipes/uclibc/uclibc-0.9.27/thumb-interwork-asm.patch @@ -0,0 +1,326 @@ +--- uClibc-0.9.27/ldso/include/dl-elf.h 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/ldso/include/dl-elf.h 2005-08-12 18:24:43.000000000 -0700 +@@ -112,6 +112,13 @@ + # define ELF_RTYPE_CLASS_COPY (0x2) + #endif + #define ELF_RTYPE_CLASS_PLT (0x1) ++/* The type class can be qualified by a list (mask) of the acceptable ++ * STT_ symbol types, if not given the default is everything numerically ++ * <= STT_FUNC (from the original code...) ++ */ ++#define ELF_RTYPE_CLASS_OF(type) ((1<<2) << (type)) ++#define ELF_RTYPE_CLASS_ALL (0xffff << 2) ++#define ELF_RTYPE_CLASS_DEFAULT (((ELF_RTYPE_CLASS_OF(STT_FUNC) << 1) - 1)&ELF_RTYPE_CLASS_ALL) + + + /* Convert between the Linux flags for page protections and the +--- uClibc-0.9.27/ldso/ldso/arm/resolve.S 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/ldso/ldso/arm/resolve.S 2005-08-13 15:08:27.523344709 -0700 +@@ -1,43 +1,117 @@ + /* +- * This function is _not_ called directly. It is jumped to (so no return +- * address is on the stack) when attempting to use a symbol that has not yet +- * been resolved. The first time a jump symbol (such as a function call inside +- * a shared library) is used (before it gets resolved) it will jump here to +- * _dl_linux_resolve. When we get called the stack looks like this: +- * reloc_entry +- * tpnt +- * +- * This function saves all the registers, puts a copy of reloc_entry and tpnt +- * on the stack (as function arguments) then make the function call +- * _dl_linux_resolver(tpnt, reloc_entry). _dl_linux_resolver() figures out +- * where the jump symbol is _really_ supposed to have jumped to and returns +- * that to us. Once we have that, we overwrite tpnt with this fixed up +- * address. We then clean up after ourselves, put all the registers back how we +- * found them, then we jump to the fixed up address, which is where the jump +- * symbol that got us here really wanted to jump to in the first place. +- * -Erik Andersen ++ * On ARM the PLT contains the following three instructions (for ARM calls): ++ * ++ * add ip, pc, #0xNN00000 ++ * add ip, ip, #0xNN000 ++ * ldr pc, [ip, #0xNNN]! ++ * ++ * So that, effectively, causes the following to happen: ++ * ++ * ip := pc+0x0NNNNNNN ++ * pc := *ip ++ * ++ * For thumb the above fragment is preceded by "bx pc, nop" to switch to ARM ++ * mode and the thumb 'bl' must go to PLT-4 - the PLT entry is expanded by ++ * four bytes to accomodate the trampoline code. ++ * ++ * 0x0NNNNNNN is the offset of the GOT entry for this function relative to ++ * the PLT entry for this function (where the code is). So the code in the ++ * PLT causes a branch to whatever is in the GOT, leaving the actual address ++ * of the GOT entry in ip. (Note that the GOT must follow the PLT - the ++ * added value is 28 bit unsigned). ++ * ++ * ip is a pointer to the GOT entry for this function, the first time round ++ * *ip points to this code: ++ * ++ * str lr, [sp, #-4]! @ save lr ++ * ldr lr, [pc, #4] @ lr := *dat (&GOT_TABLE[0]-.) ++ * add lr, pc, lr @ lr += &dat (so lr == &GOT_TABLE[0]) ++ * ldr pc, [lr, #8]! @ pc := GOT_TABLE[2] ++ *dat: .long &GOT_TABLE[0] - . ++ * ++ * (this code is actually held in the first entry of the PLT). The code ++ * preserves lr then uses it as a scratch register (this preserves the ip ++ * value calculated above). GOT_TABLE[2] is initialized by INIT_GOT in ++ * dl-sysdep.h to point to _dl_linux_resolve - this function. The first ++ * three entries in the GOT are reserved, then they are followed by the ++ * entries for the PLT entries, in order. ++ * ++ * The linker initialises the following (non-reserved) GOT entries to ++ * the offset of the PLT with an associated relocation so that on load ++ * the entry is relocated to point to the PLT - the above code. ++ * ++ * The net effect of all this is that on the first call to an external (as ++ * yet unresolved) function all seven of the above instructions are ++ * executed in sequence and the program ends up executing _dl_linux_resolve ++ * with the following important values in registers: ++ * ++ * ip - a pointer to the GOT entry for the as yet unresolved function ++ * lr - &GOT_TABLE[2] ++ * ++ * GOT_TABLE[2] has already been initialised to _dl_linux_resolve, and ++ * GOT_TABLE[1] is a pointer to the (elf_resolve*) from INIT_GOT. ++ * _dl_linux_resolve unfrobnicates the ip and lr values to obtain arguments ++ * for a call to _dl_linux_resolver (not the additional 'r' on the end) - ++ * this is in elfinterp.c in this directory. The call takes arguments: ++ * ++ * _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) ++ * ++ * And returns the address of the function, it also overwrites the GOT ++ * table entry so that the next time round only the first code fragment will ++ * be executed - it will call the function directly. ++ * ++ * [[Of course, this simply doesn't work on ARM 4T with a thumb target - because ++ * 4T did not do the thumb/arm change on ldr pc! It can be made to work by ++ * changing _dl_linux_resolver to return __%s_from_arm for an STT_TFUNC, but ++ * this hasn't been done, and there is no guarantee that the linker generated ++ * that glue anyway.]] ++ * ++ * _dl_linux_resolve gets the arguments to call the resolver as follows: ++ * ++ * tpnt GOT_TABLE[1], [lr-4] ++ * reloc-entry &GOT-&GOT_TABLE[3], (ip - lr - 4)/4 ++ * ++ * (I.e. 'GOT' means the table entry for this function, the thing for which ++ * ip holds the address.) The reloc-entry is passed as an index, since ++ * since the GOT table has 4 byte entries the code needs to divide this by 4 ++ * to get the actual index. ++ * ++ * John Bowler, August 13, 2005 - determined by experiment and examination ++ * of generated ARM code (there was no documentation...) ++ * ++ * This code is all ARM code - not thumb - _dl_linux_resolver may, itself, ++ * be thumb, in which case the linker will insert the appropriate glue. A ++ * call from thumb to the PLT hits the trampoline code described above. ++ * This code (now) builds a proper stack frame. ++ * ++ * The code does *not* set sb (r9,v6) - to do that the basic PLT instructions ++ * would need to save sb and load the new value and that would require ++ * support in the linker since it generates those instructions. (Also note ++ * that linux/uclibc seems to be using r10 - sl - as a PIC base register - see ++ * dl-startup.c). + */ + +-#define sl r10 +-#define fp r11 +-#define ip r12 +- + .text + .globl _dl_linux_resolve + .type _dl_linux_resolve,%function + .align 4; + + _dl_linux_resolve: +- stmdb sp!, {r0, r1, r2, r3, sl, fp} +- sub r1, ip, lr +- sub r1, r1, #4 +- add r1, r1, r1 +- ldr r0, [lr, #-4] +- mov r3,r0 ++ @ _dl_linux_resolver is a standard subroutine call, therefore it ++ @ preserves everything except r0-r3 (a1-a4), ip and lr. This ++ @ function must branch to the real function, and that expects ++ @ r0-r3 and lr to be as they were before the whole PLT stuff - ++ @ ip can be trashed. ++ stmdb sp!, {r0-r3} ++ ldr r0, [lr, #-4] @ r0 := [lr-4] (GOT_TABLE[1]) ++ sub r1, lr, ip @ r1 := (lr-ip) (a multple of 4) ++ mvn r1, r1, ASR #2 @ r1 := ~((lr-ip)>>2), since -x = (1+~x) ++ @ ~x = -x-1, therefore ~(r1>>2) = (-((lr-ip)>>2)-1) ++ @ = - ((lr-ip)/4) - 1 = (ip - lr - 4)/4, as required + + bl _dl_linux_resolver + +- mov ip, r0 +- ldmia sp!, {r0, r1, r2, r3, sl, fp, lr} +- mov pc,ip ++ mov ip, r0 ++ ldmia sp!, {r0-r3, lr} ++ bx ip + .size _dl_linux_resolve, .-_dl_linux_resolve +--- uClibc-0.9.27/ldso/ldso/arm/elfinterp.c 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/ldso/ldso/arm/elfinterp.c 2005-08-13 16:08:19.061345947 -0700 +@@ -128,7 +128,7 @@ + + rel_addr = (ELF_RELOC *) (tpnt->dynamic_info[DT_JMPREL] + tpnt->loadaddr); + +- this_reloc = rel_addr + (reloc_entry >> 3); ++ this_reloc = rel_addr + reloc_entry; + reloc_type = ELF32_R_TYPE(this_reloc->r_info); + symtab_index = ELF32_R_SYM(this_reloc->r_info); + +@@ -149,13 +149,20 @@ + got_addr = (char **) instr_addr; + + /* Get the address of the GOT entry */ +- new_addr = _dl_find_hash(symname, tpnt->symbol_scope, +- tpnt, ELF_RTYPE_CLASS_PLT); +- if (unlikely(!new_addr)) { +- _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", +- _dl_progname, symname); +- _dl_exit(1); +- }; ++ new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ++ ELF_RTYPE_CLASS_PLT+ELF_RTYPE_CLASS_OF(STT_FUNC)); ++ if (!new_addr) { ++ new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ++ ELF_RTYPE_CLASS_PLT+ELF_RTYPE_CLASS_OF(STT_ARM_TFUNC)); ++ if (new_addr) { ++ /* Fix up the address for thumb. */ ++ new_addr = (char*)((unsigned long)new_addr | 1); ++ } else { ++ _dl_dprintf(2, "%s: can't resolve symbol '%s'\n", ++ _dl_progname, symname); ++ _dl_exit(1); ++ } ++ } + #if defined (__SUPPORT_LD_DEBUG__) + if ((unsigned long) got_addr < 0x40000000) + { +@@ -278,7 +285,8 @@ + if (symtab_index) { + + symbol_addr = (unsigned long) _dl_find_hash(strtab + symtab[symtab_index].st_name, +- scope, tpnt, elf_machine_type_class(reloc_type)); ++ scope, tpnt, elf_machine_type_class(reloc_type) + ++ ELF_RTYPE_CLASS_DEFAULT + ELF_RTYPE_CLASS_OF(STT_ARM_TFUNC)); + + /* + * We want to allow undefined references to weak symbols - this might +--- uClibc-0.9.27/ldso/ldso/dl-hash.c 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/ldso/ldso/dl-hash.c 2005-08-12 18:28:05.000000000 -0700 +@@ -148,7 +148,11 @@ + char *weak_result = NULL; + + elf_hash_number = _dl_elf_hash(name); +- ++ /* The type class argument may specify the valid symbol types, if not ++ * any type <= STT_FUNC is permitted. ++ */ ++ if ((type_class & ELF_RTYPE_CLASS_ALL) == 0) ++ type_class += ELF_RTYPE_CLASS_DEFAULT; + for (; rpnt; rpnt = rpnt->next) { + tpnt = rpnt->dyn; + +@@ -178,13 +182,16 @@ + for (si = tpnt->elf_buckets[hn]; si != STN_UNDEF; si = tpnt->chains[si]) { + sym = &symtab[si]; + ++ /*... nb, ELF_RTYPE_CLASS_PLT is, must be, "1" - at least ++ * it must be for the following to work. ++ */ + if (type_class & (sym->st_shndx == SHN_UNDEF)) + continue; +- if (_dl_strcmp(strtab + sym->st_name, name) != 0) +- continue; + if (sym->st_value == 0) + continue; +- if (ELF32_ST_TYPE(sym->st_info) > STT_FUNC) ++ if ((ELF_RTYPE_CLASS_OF(ELF32_ST_TYPE(sym->st_info)) & type_class) == 0) ++ continue; ++ if (_dl_strcmp(strtab + sym->st_name, name) != 0) + continue; + + switch (ELF32_ST_BIND(sym->st_info)) { +--- uClibc-0.9.27/libc/sysdeps/linux/arm/clone.S 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/libc/sysdeps/linux/arm/clone.S 2005-08-13 11:56:47.275679748 -0700 +@@ -49,12 +49,13 @@ + swi __NR_clone + movs a1, a1 + blt __syscall_error (PLT) +- movne pc, lr ++ bxne lr + + @ pick the function arg and call address off the stack and execute + ldr r0, [sp, #4] ++ ldr ip, [sp] + mov lr, pc +- ldr pc, [sp] ++ bx ip + + @ and we are done, passing the return value through r0 + b _exit (PLT) +@@ -70,7 +71,7 @@ + + /* return -1 */ + mvn r0, $0 +- mov pc, lr ++ bx lr + .size __clone,.-__clone; + + .L4: .word errno +--- uClibc-0.9.27/libc/sysdeps/linux/arm/mmap64.S 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/libc/sysdeps/linux/arm/mmap64.S 2005-08-13 12:20:35.633560643 -0700 +@@ -44,7 +44,7 @@ + mov ip, r0 + swi __NR_mmap2 + cmn r0, $4096 +- ldmccfd sp!, {r4, r5, pc} ++ ldmccfd sp!, {r4, r5, pc} @ requires >=5T + cmn r0, $ENOSYS + ldmnefd sp!, {r4, r5, lr} + bne __syscall_error (PLT) +@@ -71,7 +71,7 @@ + + /* return -1 */ + mvn r0, $0 +- mov pc, lr ++ bx lr + .size mmap64,.-mmap64; + + .L4: .word errno +--- uClibc-0.9.27/libc/sysdeps/linux/arm/vfork.S 2005-01-11 23:59:21.000000000 -0800 ++++ uClibc-0.9.27/libc/sysdeps/linux/arm/vfork.S 2005-08-13 12:23:27.500375540 -0700 +@@ -37,7 +37,7 @@ + #ifdef __NR_vfork + swi __NR_vfork + cmn r0, #4096 +- movcc pc, lr ++ bxcc lr + + /* Check if vfork even exists. */ + ldr r1, =-ENOSYS +@@ -50,7 +50,7 @@ + cmn r0, #4096 + + /* Syscal worked. Return to child/parent */ +- movcc pc, lr ++ bxcc lr + + __syscall_error: + +@@ -64,7 +64,7 @@ + + /* return -1 */ + mvn r0, $0 +- mov pc, lr ++ bx lr + + .L4: .word errno + |