Gitweb links:
...log
http://git.netsurf-browser.org/toolchains.git/shortlog/0dd23cba924bd6f38541162996b08be1d880ebcc
...commit
http://git.netsurf-browser.org/toolchains.git/commit/0dd23cba924bd6f38541162996b08be1d880ebcc
...tree
http://git.netsurf-browser.org/toolchains.git/tree/0dd23cba924bd6f38541162996b08be1d880ebcc
The branch, master has been updated
via 0dd23cba924bd6f38541162996b08be1d880ebcc (commit)
from 5e7a082a1d07338dbdaaf07a307918cdc8b01162 (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
commitdiff
http://git.netsurf-browser.org/toolchains.git/commit/?id=0dd23cba924bd6f38541162996b08be1d880ebcc
commit 0dd23cba924bd6f38541162996b08be1d880ebcc
Author: John-Mark Bell <[email protected]>
Commit: John-Mark Bell <[email protected]>
arm-riscos-gnueabi: make DDT hack less invasive
Lose 2 instructions (or 25%) from the entrycode by injecting
PC-relative instructions to compute the address of the GOT pointer
and store it into the "well known" GOTT_BASE at &8038.
This does make the relocation code somewhat larger, but there is
no space limitation there, so it's less likely to break. (The
requirement for at least 3 ELF program headers still remains as,
even with this reduction in entrycode size, it's still 16 bytes
larger than the space that would be available with 2 program
headers).
diff --git a/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
b/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
index 9cb8e3f..afac755 100644
--- a/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
+++ b/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
@@ -211,7 +211,7 @@ Index: elf2aif/src/elf2aif.c
e2a_copy (FILE * elfhandle, FILE * aifhandle)
{
const phdr_list_t *phdrP;
-@@ -488,21 +584,135 @@
+@@ -488,21 +584,156 @@
}
memcpy (&aifhdr, aifcode, sizeof (aifcode));
@@ -258,11 +258,9 @@ Index: elf2aif/src/elf2aif.c
+ {
+ assert (128 == sizeof (aifcode));
+ uint32_t entrycode[] = {
-+ /* Copy GOTT_BASE, if it's in the wrong place (see below) */
-+ 0xE24FC088, /* ADR R12, &8000 */
-+ 0xE59C003C, /* LDR R0, [R12, #&3c] */
-+ 0xE3300000, /* TEQ R0, #0 */
-+ 0x158C0038, /* STRNE R0, [R12, #&38] */
++ /* Space for GOTT_BASE injection (see below) */
++ 0xE1A00000, /* MOV R0, R0 */
++ 0xE1A00000, /* MOV R0, R0 */
+ /* Install the abort handler */
+ 0xE3A00002, /* MOV R0, #2 */
+ 0xEF059D01, /* SWI ARMEABISupport_AbortOp */
@@ -279,31 +277,54 @@ Index: elf2aif/src/elf2aif.c
+ 0xE04EC00F, /* SUB R12, LR, PC */
+ 0xE08FC00C, /* ADD R12, PC, R12 */
+ 0xE24CC00C, /* SUB R12, R12, #12 */
-+ /* Prevent reentry by replacing the branch to the relocation code */
++ /* Prevent reentry by replacing the branch to the relocation code. */
+ 0xE51F0018, /* LDR R0, =RelocCode */
+ 0xE58C0004, /* STR R0, [R12, #4] */
+ /* Relocate the GOT offset (above) to its absolute address */
-+ 0xE59C009C, /* LDR R0, [R12, #&9c] */
++ 0xE59C0094, /* LDR R0, [R12, #&94] */
+ 0xE3300000, /* TEQ R0, #0 */
+ 0x1080000C, /* ADDNE R0, R0, R12 */
-+ 0xE58C009C, /* STR R0, [R12, #&9c] */
-+ /* Fill in GOTT_BASE at load + 0x38.
-+ * Unfortunately, this interacts badly with DDT, which uses
-+ * the reserved field at &8038 to temporarily store the address
-+ * of the zero-initialisation code during program start (it
-+ * subsequently puts it back after its replacement is called).
-+ * Make this less surprising by placing GOTT_BASE in the other
-+ * reserved field at &803c and then rely on the entrycode
-+ * (see above) fixing things up. Do it properly in the non-DDT
-+ * case, however, so that the OS can mark the entire RO area
-+ * non-writeable once the relocation code has completed.
-+ */
++ 0x158C0094, /* STRNE R0, [R12, #&94] */
++ /* Fill in GOTT_BASE at load + 0x38, unless running under DDT */
+ 0xE59C0038, /* LDR R0, [R12, #&38] */
+ 0xE3300000, /* TEQ R0, #0 */
-+ 0xE28C009C, /* ADD R0, R12, #&9c */
-+ 0x058C0038, /* STREQ R0, [R12, #&38] */
-+ 0x158C003C, /* STRNE R0, [R12, #&3c] */
++ 0x1A000002, /* BNE ddt_hack */
++ 0xE28C0094, /* ADD R0, R12, #&94 */
++ 0xE58C0038, /* STR R0, [R12, #&38] */
++ 0xE1A0F00E, /* MOV PC, LR */
++ /* Hack for DDT (which uses the reserved field at &8038 to
++ * temporarily store the address of the zero-initialisation code
++ * during program start, which is reinstated after DDT's
++ * replacement is called). In this case, modify the entrycode
++ * (above) to inject it for us.
++ *
++ * This does prevent the RO area being marked non-writeable if
++ * the modified entrycode gets executed, however (in the non-DDT
++ * case, the entrycode does not write to the AIF header, so
++ * there is no reason the RO area can't be non-writeable then).
++ * By definition the RO area must be writeable for relocations to
++ * work, so it is perfectly safe to assume that it is when this
++ * code runs.
++ */
++ /* ddt_hack: */
++ 0xE59F001C, /* LDR R0, =ddt_hack_data */
++ 0xE59F101C, /* LDR R1, =ddt_hack_data+4 */
++ 0xE58C0080, /* STR R0, [R12, #&80] */
++ 0xE58C1084, /* STR R1, [R12, #&84] */
++ /* Invalidate instruction cache */
++ 0xE3A00001, /* MOV R0, #1 */
++ 0xE28C1080, /* ADD R1, R12, #&80 */
++ 0xE28C2088, /* ADD R2, R12, #&88 */
++ 0xEF02006E, /* SWI XOSSynchroniseCodeAreas */
+ 0xE1A0F00E, /* MOV PC, LR */
++ /* Instructions to inject into entrycode. Uses PC-relative
++ * addressing, so must be kept in sync with changes to entrycode
++ * or the location of entrycode within memory. */
++ /* ddt_hack_data: */
++ /* Compute address of GOT field after entrycode */
++ 0xE28F000C, /* ADR R0, got_address */
++ /* Store computed address in GOTT_BASE (load + 0x38) */
++ 0xE50F0054, /* STR R0, [pc, #-&54] */
+ /* Relocation sentinel: just in case anything expects one */
+ 0xFFFFFFFF, /* DCD -1 */
+ };
@@ -319,12 +340,12 @@ Index: elf2aif/src/elf2aif.c
+ if (opt_verbose)
+ printf ("Writing EABI entry code at offset 0x%x\n", sizeof (aifcode));
+
-+ entrycode[6] |= (exec_addr - load_addr - (sizeof (aifcode) + 6*4 + 8))
>> 2;
++ entrycode[4] |= (exec_addr - load_addr - (sizeof (aifcode) + 4*4 + 8))
>> 2;
+ if (got_addr)
+ {
+ if (opt_verbose)
+ printf ("Found GOT at 0x%x\n", got_addr);
-+ entrycode[7] = (got_addr - load_addr);
++ entrycode[5] = (got_addr - load_addr);
+ }
+ if (fseek (aifhandle, sizeof (aifcode), SEEK_SET) != 0
+ || fwrite (&entrycode, sizeof (entrycode), 1, aifhandle) != 1)
@@ -353,7 +374,7 @@ Index: elf2aif/src/elf2aif.c
return EXIT_SUCCESS;
}
-@@ -557,6 +767,7 @@
+@@ -557,6 +788,7 @@
elf_filename = elffilename;
if (e2a_readehdr (elfhandle) == EXIT_SUCCESS
@@ -361,7 +382,7 @@ Index: elf2aif/src/elf2aif.c
&& e2a_readphdr (elfhandle) == EXIT_SUCCESS
&& e2a_copy (elfhandle, aifhandle) == EXIT_SUCCESS)
status = EXIT_SUCCESS;
-@@ -683,6 +894,9 @@
+@@ -683,6 +915,9 @@
fprintf (stderr, "Warning: extra options/arguments ignored\n");
return EXIT_SUCCESS;
}
-----------------------------------------------------------------------
Summary of changes:
.../recipes/patches/gccsdk/elf2aif-eabi-support.p | 75 +++++++++++++-------
1 file changed, 48 insertions(+), 27 deletions(-)
diff --git a/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
b/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
index 9cb8e3f..afac755 100644
--- a/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
+++ b/arm-riscos-gnueabi/recipes/patches/gccsdk/elf2aif-eabi-support.p
@@ -211,7 +211,7 @@ Index: elf2aif/src/elf2aif.c
e2a_copy (FILE * elfhandle, FILE * aifhandle)
{
const phdr_list_t *phdrP;
-@@ -488,21 +584,135 @@
+@@ -488,21 +584,156 @@
}
memcpy (&aifhdr, aifcode, sizeof (aifcode));
@@ -258,11 +258,9 @@ Index: elf2aif/src/elf2aif.c
+ {
+ assert (128 == sizeof (aifcode));
+ uint32_t entrycode[] = {
-+ /* Copy GOTT_BASE, if it's in the wrong place (see below) */
-+ 0xE24FC088, /* ADR R12, &8000 */
-+ 0xE59C003C, /* LDR R0, [R12, #&3c] */
-+ 0xE3300000, /* TEQ R0, #0 */
-+ 0x158C0038, /* STRNE R0, [R12, #&38] */
++ /* Space for GOTT_BASE injection (see below) */
++ 0xE1A00000, /* MOV R0, R0 */
++ 0xE1A00000, /* MOV R0, R0 */
+ /* Install the abort handler */
+ 0xE3A00002, /* MOV R0, #2 */
+ 0xEF059D01, /* SWI ARMEABISupport_AbortOp */
@@ -279,31 +277,54 @@ Index: elf2aif/src/elf2aif.c
+ 0xE04EC00F, /* SUB R12, LR, PC */
+ 0xE08FC00C, /* ADD R12, PC, R12 */
+ 0xE24CC00C, /* SUB R12, R12, #12 */
-+ /* Prevent reentry by replacing the branch to the relocation code */
++ /* Prevent reentry by replacing the branch to the relocation code. */
+ 0xE51F0018, /* LDR R0, =RelocCode */
+ 0xE58C0004, /* STR R0, [R12, #4] */
+ /* Relocate the GOT offset (above) to its absolute address */
-+ 0xE59C009C, /* LDR R0, [R12, #&9c] */
++ 0xE59C0094, /* LDR R0, [R12, #&94] */
+ 0xE3300000, /* TEQ R0, #0 */
+ 0x1080000C, /* ADDNE R0, R0, R12 */
-+ 0xE58C009C, /* STR R0, [R12, #&9c] */
-+ /* Fill in GOTT_BASE at load + 0x38.
-+ * Unfortunately, this interacts badly with DDT, which uses
-+ * the reserved field at &8038 to temporarily store the address
-+ * of the zero-initialisation code during program start (it
-+ * subsequently puts it back after its replacement is called).
-+ * Make this less surprising by placing GOTT_BASE in the other
-+ * reserved field at &803c and then rely on the entrycode
-+ * (see above) fixing things up. Do it properly in the non-DDT
-+ * case, however, so that the OS can mark the entire RO area
-+ * non-writeable once the relocation code has completed.
-+ */
++ 0x158C0094, /* STRNE R0, [R12, #&94] */
++ /* Fill in GOTT_BASE at load + 0x38, unless running under DDT */
+ 0xE59C0038, /* LDR R0, [R12, #&38] */
+ 0xE3300000, /* TEQ R0, #0 */
-+ 0xE28C009C, /* ADD R0, R12, #&9c */
-+ 0x058C0038, /* STREQ R0, [R12, #&38] */
-+ 0x158C003C, /* STRNE R0, [R12, #&3c] */
++ 0x1A000002, /* BNE ddt_hack */
++ 0xE28C0094, /* ADD R0, R12, #&94 */
++ 0xE58C0038, /* STR R0, [R12, #&38] */
++ 0xE1A0F00E, /* MOV PC, LR */
++ /* Hack for DDT (which uses the reserved field at &8038 to
++ * temporarily store the address of the zero-initialisation code
++ * during program start, which is reinstated after DDT's
++ * replacement is called). In this case, modify the entrycode
++ * (above) to inject it for us.
++ *
++ * This does prevent the RO area being marked non-writeable if
++ * the modified entrycode gets executed, however (in the non-DDT
++ * case, the entrycode does not write to the AIF header, so
++ * there is no reason the RO area can't be non-writeable then).
++ * By definition the RO area must be writeable for relocations to
++ * work, so it is perfectly safe to assume that it is when this
++ * code runs.
++ */
++ /* ddt_hack: */
++ 0xE59F001C, /* LDR R0, =ddt_hack_data */
++ 0xE59F101C, /* LDR R1, =ddt_hack_data+4 */
++ 0xE58C0080, /* STR R0, [R12, #&80] */
++ 0xE58C1084, /* STR R1, [R12, #&84] */
++ /* Invalidate instruction cache */
++ 0xE3A00001, /* MOV R0, #1 */
++ 0xE28C1080, /* ADD R1, R12, #&80 */
++ 0xE28C2088, /* ADD R2, R12, #&88 */
++ 0xEF02006E, /* SWI XOSSynchroniseCodeAreas */
+ 0xE1A0F00E, /* MOV PC, LR */
++ /* Instructions to inject into entrycode. Uses PC-relative
++ * addressing, so must be kept in sync with changes to entrycode
++ * or the location of entrycode within memory. */
++ /* ddt_hack_data: */
++ /* Compute address of GOT field after entrycode */
++ 0xE28F000C, /* ADR R0, got_address */
++ /* Store computed address in GOTT_BASE (load + 0x38) */
++ 0xE50F0054, /* STR R0, [pc, #-&54] */
+ /* Relocation sentinel: just in case anything expects one */
+ 0xFFFFFFFF, /* DCD -1 */
+ };
@@ -319,12 +340,12 @@ Index: elf2aif/src/elf2aif.c
+ if (opt_verbose)
+ printf ("Writing EABI entry code at offset 0x%x\n", sizeof (aifcode));
+
-+ entrycode[6] |= (exec_addr - load_addr - (sizeof (aifcode) + 6*4 + 8))
>> 2;
++ entrycode[4] |= (exec_addr - load_addr - (sizeof (aifcode) + 4*4 + 8))
>> 2;
+ if (got_addr)
+ {
+ if (opt_verbose)
+ printf ("Found GOT at 0x%x\n", got_addr);
-+ entrycode[7] = (got_addr - load_addr);
++ entrycode[5] = (got_addr - load_addr);
+ }
+ if (fseek (aifhandle, sizeof (aifcode), SEEK_SET) != 0
+ || fwrite (&entrycode, sizeof (entrycode), 1, aifhandle) != 1)
@@ -353,7 +374,7 @@ Index: elf2aif/src/elf2aif.c
return EXIT_SUCCESS;
}
-@@ -557,6 +767,7 @@
+@@ -557,6 +788,7 @@
elf_filename = elffilename;
if (e2a_readehdr (elfhandle) == EXIT_SUCCESS
@@ -361,7 +382,7 @@ Index: elf2aif/src/elf2aif.c
&& e2a_readphdr (elfhandle) == EXIT_SUCCESS
&& e2a_copy (elfhandle, aifhandle) == EXIT_SUCCESS)
status = EXIT_SUCCESS;
-@@ -683,6 +894,9 @@
+@@ -683,6 +915,9 @@
fprintf (stderr, "Warning: extra options/arguments ignored\n");
return EXIT_SUCCESS;
}
--
Cross-compilation toolchains and environments
_______________________________________________
netsurf-commits mailing list -- [email protected]
To unsubscribe send an email to [email protected]
