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Re: [Patch,AVR]: PR13503: Add expression modifiers/RELOCs for data.
- From: Georg-Johann Lay <avr at gjlay dot de>
- To: binutils at sourceware dot org
- Cc: Denis Chertykov <chertykov at gmail dot com>, Eric Weddington <eric dot weddington at atmel dot com>, Bjoern Haase <bjoern dot m dot haase at web dot de>
- Date: Thu, 26 Apr 2012 19:36:43 +0200
- Subject: Re: [Patch,AVR]: PR13503: Add expression modifiers/RELOCs for data.
- References: <4F96F13D.7080205@gjlay.de>
Georg-Johann Lay wrote:
> This patch adds new expression modifiers for 1-byte data
> to get sub-bytes of byte addresses like in:
>
> .byte lo8(expr)
> .byte hi8(expr)
> .byte hhi8(expr)
> .byte hh8(expr)
>
> The semantics of these new modifiers is the same as the semantics of
> respective modifiers that are already allowed in instruction operands.
> hh8 is just an alias for hhi8.
>
> These modifiers are needed to support the __memx address space of avr-gcc:
>
> extern const __memx char foo;
> const __memx void *pfoo = &foo;
>
> &foo and pfoo are 24-bit values.
> Currently, avr-gcc emits an assembler warning for the code above to
> hint that the feature is not supported by binutils.
>
>
> This is my first patch to binutils so I am unsure about its completeness
> and correctness; in particular:
>
> * I don't understand the documentation of 'dst_mask' and 'pcrel_offset'
> from ./bfd/reloc.c and if their initialization in the new HOWTOs in
> ./bfd/elf32-avr.c is correct.
>
> * If there is anything missing, like extra processing in
> ./gas/config/tc-avr.c:md_apply_fix() or in other places.
> Or does it work out of the box by HOWTO descriptions?
Hi, this is an updated patch that handles the new RELOCs in
gas/config/tc-avr.c:md_apply_fix()
case BFD_RELOC_AVR_8_LO:
*where = 0xff & value;
break;
case BFD_RELOC_AVR_8_HI:
*where = 0xff & (value >> 8);
break;
case BFD_RELOC_AVR_8_HHI:
*where = 0xff & (value >> 16);
break;
> Up to now, I have no GPL copyright assignment on file.
> I requested the paperwork from FSF
I sent back the papers to the FSF and hope the paperwork it finished soon.
Johann
bfd/
PR 13503
* reloc.c: Add new ENUM for BFD_RELOC_AVR_8_LO,
BFD_RELOC_AVR_8_HI, BFD_RELOC_AVR_8_HHI.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenrate.
* elf32-avr.c (elf_avr_howto_table): Add entries for
R_AVR_8_LO8, R_AVR_8_HI8, R_AVR_8_HHI8.
(avr_reloc_map): Add RELOC mappings for R_AVR_8_LO8, R_AVR_8_HI8,
R_AVR_8_HHI8.
gas/
PR 13503
* config/tc-avr.c (exp_mod_pm): Remove variable.
(exp_mod_data_t): New typedef.
(pexp_mod_data, exp_mod_data): New variables.
(avr_parse_cons_expression): Scan through exp_mod_data[] to find
data expression modifiers "pm", "gs", "lo8", hi8", "hhi8", "hh8"
and set pexp_mod_data accordingly to be used in avr_cons_fix_new.
(avr_cons_fix_new): Handle new data expression modifiers shipped
in pexp_mod_data.
(md_apply_fix): Handle BFD_RELOC_AVR_8_LO, BFD_RELOC_AVR_8_HI,
BFD_RELOC_AVR_8_HHI.
include/
PR 13503
* elf/avr.h (RELOC_NUMBERS): Add values for R_AVR_8_LO8,
R_AVR_8_HI8, R_AVR_8_HHI8.
Index: bfd/bfd-in2.h
===================================================================
RCS file: /cvs/src/src/bfd/bfd-in2.h,v
retrieving revision 1.566
diff -u -p -r1.566 bfd-in2.h
--- bfd/bfd-in2.h 26 Apr 2012 13:49:52 -0000 1.566
+++ bfd/bfd-in2.h 26 Apr 2012 17:28:47 -0000
@@ -4089,6 +4089,18 @@ instructions */
instructions */
BFD_RELOC_AVR_6_ADIW,
+/* This is a 8 bit reloc for the AVR that stores bits 0..7 of a symbol
+in .byte lo8(symbol) */
+ BFD_RELOC_AVR_8_LO,
+
+/* This is a 8 bit reloc for the AVR that stores bits 8..15 of a symbol
+in .byte hi8(symbol) */
+ BFD_RELOC_AVR_8_HI,
+
+/* This is a 8 bit reloc for the AVR that stores bits 16..23 of a symbol
+in .byte hhi8(symbol) */
+ BFD_RELOC_AVR_8_HHI,
+
/* Renesas RL78 Relocations. */
BFD_RELOC_RL78_NEG8,
BFD_RELOC_RL78_NEG16,
Index: bfd/elf32-avr.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-avr.c,v
retrieving revision 1.54
diff -u -p -r1.54 elf32-avr.c
--- bfd/elf32-avr.c 24 Apr 2012 05:12:31 -0000 1.54
+++ bfd/elf32-avr.c 26 Apr 2012 17:28:49 -0000
@@ -517,6 +517,48 @@ static reloc_howto_type elf_avr_howto_ta
0x000000ff, /* src_mask */
0x000000ff, /* dst_mask */
FALSE), /* pcrel_offset */
+ /* lo8-part to use in .byte lo8(sym). */
+ HOWTO (R_AVR_8_LO8, /* type */
+ 0, /* rightshift */
+ 0, /* size (0 = byte, 1 = short, 2 = long) */
+ 8, /* bitsize */
+ FALSE, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_dont,/* complain_on_overflow */
+ bfd_elf_generic_reloc, /* special_function */
+ "R_AVR_8_LO8", /* name */
+ FALSE, /* partial_inplace */
+ 0xffffff, /* src_mask */
+ 0xffffff, /* dst_mask */
+ FALSE), /* pcrel_offset */
+ /* hi8-part to use in .byte hi8(sym). */
+ HOWTO (R_AVR_8_HI8, /* type */
+ 8, /* rightshift */
+ 0, /* size (0 = byte, 1 = short, 2 = long) */
+ 8, /* bitsize */
+ FALSE, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_dont,/* complain_on_overflow */
+ bfd_elf_generic_reloc, /* special_function */
+ "R_AVR_8_HI8", /* name */
+ FALSE, /* partial_inplace */
+ 0xffffff, /* src_mask */
+ 0xffffff, /* dst_mask */
+ FALSE), /* pcrel_offset */
+ /* hhi8-part to use in .byte hhi8(sym). */
+ HOWTO (R_AVR_8_HHI8, /* type */
+ 16, /* rightshift */
+ 0, /* size (0 = byte, 1 = short, 2 = long) */
+ 8, /* bitsize */
+ FALSE, /* pc_relative */
+ 0, /* bitpos */
+ complain_overflow_dont,/* complain_on_overflow */
+ bfd_elf_generic_reloc, /* special_function */
+ "R_AVR_8_HHI8", /* name */
+ FALSE, /* partial_inplace */
+ 0xffffff, /* src_mask */
+ 0xffffff, /* dst_mask */
+ FALSE), /* pcrel_offset */
};
/* Map BFD reloc types to AVR ELF reloc types. */
@@ -555,7 +597,10 @@ static const struct avr_reloc_map avr_re
{ BFD_RELOC_AVR_LDI, R_AVR_LDI },
{ BFD_RELOC_AVR_6, R_AVR_6 },
{ BFD_RELOC_AVR_6_ADIW, R_AVR_6_ADIW },
- { BFD_RELOC_8, R_AVR_8 }
+ { BFD_RELOC_8, R_AVR_8 },
+ { BFD_RELOC_AVR_8_LO, R_AVR_8_LO8 },
+ { BFD_RELOC_AVR_8_HI, R_AVR_8_HI8 },
+ { BFD_RELOC_AVR_8_HHI, R_AVR_8_HHI8 }
};
/* Meant to be filled one day with the wrap around address for the
Index: bfd/libbfd.h
===================================================================
RCS file: /cvs/src/src/bfd/libbfd.h,v
retrieving revision 1.272
diff -u -p -r1.272 libbfd.h
--- bfd/libbfd.h 26 Apr 2012 13:49:51 -0000 1.272
+++ bfd/libbfd.h 26 Apr 2012 17:28:51 -0000
@@ -1867,6 +1867,9 @@ static const char *const bfd_reloc_code_
"BFD_RELOC_AVR_LDI",
"BFD_RELOC_AVR_6",
"BFD_RELOC_AVR_6_ADIW",
+ "BFD_RELOC_AVR_8_LO",
+ "BFD_RELOC_AVR_8_HI",
+ "BFD_RELOC_AVR_8_HHI",
"BFD_RELOC_RL78_NEG8",
"BFD_RELOC_RL78_NEG16",
"BFD_RELOC_RL78_NEG24",
Index: bfd/reloc.c
===================================================================
RCS file: /cvs/src/src/bfd/reloc.c,v
retrieving revision 1.226
diff -u -p -r1.226 reloc.c
--- bfd/reloc.c 24 Apr 2012 05:12:39 -0000 1.226
+++ bfd/reloc.c 26 Apr 2012 17:28:54 -0000
@@ -4360,6 +4360,21 @@ ENUM
ENUMDOC
This is a 6 bit reloc for the AVR that stores offset for adiw/sbiw
instructions
+ENUM
+ BFD_RELOC_AVR_8_LO
+ENUMDOC
+ This is a 8 bit reloc for the AVR that stores bits 0..7 of a symbol
+ in .byte lo8(symbol)
+ENUM
+ BFD_RELOC_AVR_8_HI
+ENUMDOC
+ This is a 8 bit reloc for the AVR that stores bits 8..15 of a symbol
+ in .byte hi8(symbol)
+ENUM
+ BFD_RELOC_AVR_8_HHI
+ENUMDOC
+ This is a 8 bit reloc for the AVR that stores bits 16..23 of a symbol
+ in .byte hhi8(symbol)
ENUM
BFD_RELOC_RL78_NEG8
Index: gas/config/tc-avr.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-avr.c,v
retrieving revision 1.80
diff -u -p -r1.80 tc-avr.c
--- gas/config/tc-avr.c 17 Apr 2012 13:59:40 -0000 1.80
+++ gas/config/tc-avr.c 26 Apr 2012 17:28:55 -0000
@@ -1334,7 +1334,19 @@ md_apply_fix (fixS *fixP, valueT * valP,
}
break;
- default:
+ case BFD_RELOC_AVR_8_LO:
+ *where = 0xff & value;
+ break;
+
+ case BFD_RELOC_AVR_8_HI:
+ *where = 0xff & (value >> 8);
+ break;
+
+ case BFD_RELOC_AVR_8_HHI:
+ *where = 0xff & (value >> 16);
+ break;
+
+ default:
as_fatal (_("line %d: unknown relocation type: 0x%x"),
fixP->fx_line, fixP->fx_r_type);
break;
@@ -1465,40 +1477,75 @@ md_assemble (char *str)
}
}
-/* Flag to pass `pm' mode between `avr_parse_cons_expression' and
- `avr_cons_fix_new'. */
-static int exp_mod_pm = 0;
-
-/* Parse special CONS expression: pm (expression)
- or alternatively: gs (expression).
- These are used for addressing program memory.
- Relocation: BFD_RELOC_AVR_16_PM. */
+typedef struct
+{
+ /* Name of the expression modifier allowed with .byte, .word, etc. */
+ const char *name;
+
+ /* Only allowed with n bytes of data. */
+ int nbytes;
+
+ /* Associated RELOC. */
+ bfd_reloc_code_real_type reloc;
+
+ /* Part of the error message. */
+ const char *error;
+} exp_mod_data_t;
+
+static const exp_mod_data_t exp_mod_data[] =
+{
+ /* Default, must be first. */
+ { "", 0, BFD_RELOC_16, "" },
+ /* Divides by 2 to get word address. Generate Stub. */
+ { "gs", 2, BFD_RELOC_AVR_16_PM, "`gs' " },
+ { "pm", 2, BFD_RELOC_AVR_16_PM, "`pm' " },
+ /* The following are used together with avr-gcc's __memx address space
+ in order to initialize a 24-bit pointer variable with a 24-bit address.
+ For address in flash, hhi8 will contain the flash segment if the
+ symbol is located in flash. If the symbol is located in RAM; hhi8
+ will contain 0x80 which matches avr-gcc's notion of how 24-bit RAM/flash
+ addresses linearize address space. */
+ { "lo8", 1, BFD_RELOC_AVR_8_LO, "`lo8' " },
+ { "hi8", 1, BFD_RELOC_AVR_8_HI, "`hi8' " },
+ { "hhi8", 1, BFD_RELOC_AVR_8_HHI, "`hhi8' " },
+ { "hh8", 1, BFD_RELOC_AVR_8_HHI, "`hh8' " },
+ /* End of list. */
+ { NULL, 0, 0, NULL }
+};
+
+/* Data to pass between `avr_parse_cons_expression' and `avr_cons_fix_new'. */
+static const exp_mod_data_t *pexp_mod_data = &exp_mod_data[0];
+
+/* Parse special CONS expression: pm (expression) or alternatively
+ gs (expression). These are used for addressing program memory. Moreover,
+ define lo8 (expression), hi8 (expression) and hhi8 (expression). */
void
avr_parse_cons_expression (expressionS *exp, int nbytes)
{
+ const exp_mod_data_t *pexp = &exp_mod_data[0];
char *tmp;
- exp_mod_pm = 0;
+ pexp_mod_data = pexp;
tmp = input_line_pointer = skip_space (input_line_pointer);
- if (nbytes == 2)
+ /* The first entry of exp_mod_data[] contains an entry if no
+ expression modifier is present. Skip it. */
+
+ for (pexp++; pexp->name; pexp++)
{
- char *pm_name1 = "pm";
- char *pm_name2 = "gs";
- int len = strlen (pm_name1);
- /* len must be the same for both pm identifiers. */
+ int len = strlen (pexp->name);
- if (strncasecmp (input_line_pointer, pm_name1, len) == 0
- || strncasecmp (input_line_pointer, pm_name2, len) == 0)
+ if (nbytes == pexp->nbytes
+ && strncasecmp (input_line_pointer, pexp->name, len) == 0)
{
input_line_pointer = skip_space (input_line_pointer + len);
if (*input_line_pointer == '(')
{
input_line_pointer = skip_space (input_line_pointer + 1);
- exp_mod_pm = 1;
+ pexp_mod_data = pexp;
expression (exp);
if (*input_line_pointer == ')')
@@ -1506,13 +1553,15 @@ avr_parse_cons_expression (expressionS *
else
{
as_bad (_("`)' required"));
- exp_mod_pm = 0;
+ pexp_mod_data = &exp_mod_data[0];
}
return;
}
input_line_pointer = tmp;
+
+ break;
}
}
@@ -1525,8 +1574,11 @@ avr_cons_fix_new (fragS *frag,
int nbytes,
expressionS *exp)
{
- if (exp_mod_pm == 0)
+ int bad = 0;
+
+ switch (pexp_mod_data->reloc)
{
+ default:
if (nbytes == 1)
fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_8);
else if (nbytes == 2)
@@ -1534,16 +1586,24 @@ avr_cons_fix_new (fragS *frag,
else if (nbytes == 4)
fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_32);
else
- as_bad (_("illegal %srelocation size: %d"), "", nbytes);
- }
- else
- {
- if (nbytes == 2)
- fix_new_exp (frag, where, nbytes, exp, FALSE, BFD_RELOC_AVR_16_PM);
+ bad = 1;
+ break;
+
+ case BFD_RELOC_AVR_16_PM:
+ case BFD_RELOC_AVR_8_LO:
+ case BFD_RELOC_AVR_8_HI:
+ case BFD_RELOC_AVR_8_HHI:
+ if (nbytes == pexp_mod_data->nbytes)
+ fix_new_exp (frag, where, nbytes, exp, FALSE, pexp_mod_data->reloc);
else
- as_bad (_("illegal %srelocation size: %d"), "`pm' ", nbytes);
- exp_mod_pm = 0;
+ bad = 1;
+ break;
}
+
+ if (bad)
+ as_bad (_("illegal %srelocation size: %d"), pexp_mod_data->error, nbytes);
+
+ pexp_mod_data = &exp_mod_data[0];
}
void
Index: include/elf/avr.h
===================================================================
RCS file: /cvs/src/src/include/elf/avr.h,v
retrieving revision 1.12
diff -u -p -r1.12 avr.h
--- include/elf/avr.h 22 Mar 2011 18:10:44 -0000 1.12
+++ include/elf/avr.h 26 Apr 2012 17:28:59 -0000
@@ -77,6 +77,9 @@ START_RELOC_NUMBERS (elf_avr_reloc_type)
RELOC_NUMBER (R_AVR_LO8_LDI_GS, 24)
RELOC_NUMBER (R_AVR_HI8_LDI_GS, 25)
RELOC_NUMBER (R_AVR_8, 26)
+ RELOC_NUMBER (R_AVR_8_LO8, 27)
+ RELOC_NUMBER (R_AVR_8_HI8, 28)
+ RELOC_NUMBER (R_AVR_8_HHI8, 29)
END_RELOC_NUMBERS (R_AVR_max)
#endif /* _ELF_AVR_H */