Allow a configuration to specify an arbitrary address where the
compressed kernel image is located, in the event it can't be appended
to or embedded within the gzboot binary itself.

1. All Makefiles that use ARM_APCS_FLAGS add -marm unconditionally and
bsd.own.mk also adds it for gcc only (so we end up with 2 -marm for gcc).
Just add -marm unconditionally in bsd.own.mk in ARM_APCS_FLAGS and remove
it from everywhere else.
2. gcc-8 now warns about thumb internetwork in APCS mode. This does not make
sense because the documentation says that this flag does not make a
difference in apcs mode, but might produce larger code in non-APCS mode.
So we just add it to silence the warnings.

centralize vers.c building for standalone programs.

GC more logic that was intended for GCC <4.8 (or !LLVM)

Same as before (-marm implies -mno-thumb), but now the condition was flipped

branches: 1.34.2; 1.34.4;
Don't reuse LDFLAGS for arguments passed directly to ${LD}, share/mk
expects it to be passed to ${CC} or ${CXX}, so they will generally
prefix flags with -Wl.

remove the MKPIE and MKCTF no hack, and move it to the .mk files

Disable PIE and CTF for standalone code
XXX: Must be done centrally, and there must be a better way.

Clear STRIPFLAGS (stripping in general is dangerous with the -BE8 object
format, and should never be done before the final linking has happened).
From Rin Okuyama.

branches: 1.30.6;
Add empty LIBCRTI= as LIBCRT0 to build sa programs without installed DESTDIR.

XXX: probabry we should have bsd.saprog.mk or something.

Move flags for ARM's APCS ABI into a common variable. Add some forces to
deal with limitations in the Clang <-> LLVM backend interaction to pick
the correct ABI and target assembler.

Use -marm for clang builds, too.

explicitly add -marm

-mno-thumb-interwork is the default, and there is no -mthumb in gcc 4.8

Use <bsd.klinks.mk>

Add CPPFLAGS+= -mno-thumb -mno-thumb-interwork

branches: 1.23.2;
Add -fno-unwind-tables

gcc will supply -Wa,-eabi=gnu so don't include. Use -mabi=apcs-base, not atpcs

Make sure these are always compiled with -mabi=atpcs -mfloat-abi=soft
-Wa,-meabi=gnu so they use the old compilation methods.

branches: 1.20.2;
Fixed build with USE_SSP=yes

ok christos@

Fix to allow EABI compilation.
Make sure to DISCARD new .ARM.attributes and .ARM.ebxidx sections.

Add missing ${_MKTARGET_LINK}

branches: 1.17.4; 1.17.10;
Drop bootprog_maker (formerly enabled by -M) and bootprog_date (formerly
disabled by -D) from the output of newvers_stand.sh. Change -D to the
inverted logic, so that it adds the date to bootprog_rev in ().

Change all platforms accordingly. -D is added if MKREPRO is not yes and
wasn't present before. Platforms that didn't use -D don't depend on
MKREPRO now either.

branches: 1.16.2; 1.16.4;
Introduce .WAIT into the cleandir rule for blasting the libsa/libkern/etc.
trees, because it can race with the libsa/libkern/etc. makefiles' own
cleandir rules. I think I've found all of the uses of the offending idiom...
Closes PR 43360.

branches: 1.15.4; 1.15.6;
- WARNSfy
- add src/common/dist/zlib to incpath for build without DESTDIR

branches: 1.14.72; 1.14.76; 1.14.84;
The new zlib uses HEAP_SIZE, so instead use BOARD_HEAP_SIZE as the
symbol to use here. Also adapt to the new zlib with the changed name
for the header file.

branches: 1.13.2;
merge ktrace-lwp.

branches: 1.12.2;
dependencies for .BEGIN is not accepted by the latest nbmake.

include <bsd.obj.mk> to teach make the rules for OBJDIR names.

This is to fix a problem on compiling gzboot with BUILDID defined
(by build.sh -B BUILDID).

branches: 1.10.4; 1.10.6; 1.10.10;
Ignore errors on some rm -rf's for platforms that aren't quite
POSIX compliant
and return errors on r/o source (FreeBSD) for -rf. Fixes PR#25022

branches: 1.9.2;
Use ${HOST_SH} instead of `sh'.

If necessary, pull in <bsd.sys.mk> to get the definition of HOST_SH;
Makefiles that pull in one of (most of) <bsd.*.mk> will get this anyway.

branches: 1.8.2;
* Add ${PROGSYM} to CLEANFILES.
* Instsall either the .bin or the .sym, based on whether or not
the resulting gzboot needs to be mdsetimage'd.

Also build a flat binary version of the gzboot program.

Garbage-collect the DYNAMIC_CRC_TABLE stuff. The table it computed
was incompatible with the new CRC code, and it is largely unnecessary
now, since the static table is so much smaller.

Fixes PR kern/20935.

branches: 1.5.6;
Give gzboot a 1M heap, so that loading gzip -9'd kernels works
reliably.

branches: 1.4.2;
Add support for relocating gzboot's .text out of flash and into
RAM (while still decompressing the image directly from flash).

This makes gzboot run a LOT faster.

Fix the -DRELOC=... CPP flag. Add -DDYNAMIC_CRC_TABLE to shrink
the text (and, thus, the space taken up in flash) a bit.

Add support for running directly out of flash:
* Require that the builder Makefile provide a linker script.
* After making sure the MMU is disabled, check to see if
_etext == __data_start. If not, then copy the .data contents
into RAM.
* Put the stack in .bss.

gzboot -- boot a gzip'd kernel image. This is useful for booting
compressed kernel images from flash.

This needs more work, but is a good first-pass.

1. All Makefiles that use ARM_APCS_FLAGS add -marm unconditionally and
bsd.own.mk also adds it for gcc only (so we end up with 2 -marm for gcc).
Just add -marm unconditionally in bsd.own.mk in ARM_APCS_FLAGS and remove
it from everywhere else.
2. gcc-8 now warns about thumb internetwork in APCS mode. This does not make
sense because the documentation says that this flag does not make a
difference in apcs mode, but might produce larger code in non-APCS mode.
So we just add it to silence the warnings.

centralize vers.c building for standalone programs.

GC more logic that was intended for GCC <4.8 (or !LLVM)

Same as before (-marm implies -mno-thumb), but now the condition was flipped

branches: 1.34.2; 1.34.4;
Don't reuse LDFLAGS for arguments passed directly to ${LD}, share/mk
expects it to be passed to ${CC} or ${CXX}, so they will generally
prefix flags with -Wl.

remove the MKPIE and MKCTF no hack, and move it to the .mk files

Disable PIE and CTF for standalone code
XXX: Must be done centrally, and there must be a better way.

Clear STRIPFLAGS (stripping in general is dangerous with the -BE8 object
format, and should never be done before the final linking has happened).
From Rin Okuyama.

branches: 1.30.6;
Add empty LIBCRTI= as LIBCRT0 to build sa programs without installed DESTDIR.

XXX: probabry we should have bsd.saprog.mk or something.

Move flags for ARM's APCS ABI into a common variable. Add some forces to
deal with limitations in the Clang <-> LLVM backend interaction to pick
the correct ABI and target assembler.

Use -marm for clang builds, too.

explicitly add -marm

-mno-thumb-interwork is the default, and there is no -mthumb in gcc 4.8

Use <bsd.klinks.mk>

Add CPPFLAGS+= -mno-thumb -mno-thumb-interwork

branches: 1.23.2;
Add -fno-unwind-tables

gcc will supply -Wa,-eabi=gnu so don't include. Use -mabi=apcs-base, not atpcs

Make sure these are always compiled with -mabi=atpcs -mfloat-abi=soft
-Wa,-meabi=gnu so they use the old compilation methods.

branches: 1.20.2;
Fixed build with USE_SSP=yes

ok christos@

Fix to allow EABI compilation.
Make sure to DISCARD new .ARM.attributes and .ARM.ebxidx sections.

Add missing ${_MKTARGET_LINK}

branches: 1.17.4; 1.17.10;
Drop bootprog_maker (formerly enabled by -M) and bootprog_date (formerly
disabled by -D) from the output of newvers_stand.sh. Change -D to the
inverted logic, so that it adds the date to bootprog_rev in ().

Change all platforms accordingly. -D is added if MKREPRO is not yes and
wasn't present before. Platforms that didn't use -D don't depend on
MKREPRO now either.

branches: 1.16.2; 1.16.4;
Introduce .WAIT into the cleandir rule for blasting the libsa/libkern/etc.
trees, because it can race with the libsa/libkern/etc. makefiles' own
cleandir rules. I think I've found all of the uses of the offending idiom...
Closes PR 43360.

branches: 1.15.4; 1.15.6;
- WARNSfy
- add src/common/dist/zlib to incpath for build without DESTDIR

branches: 1.14.72; 1.14.76; 1.14.84;
The new zlib uses HEAP_SIZE, so instead use BOARD_HEAP_SIZE as the
symbol to use here. Also adapt to the new zlib with the changed name
for the header file.

branches: 1.13.2;
merge ktrace-lwp.

branches: 1.12.2;
dependencies for .BEGIN is not accepted by the latest nbmake.

include <bsd.obj.mk> to teach make the rules for OBJDIR names.

This is to fix a problem on compiling gzboot with BUILDID defined
(by build.sh -B BUILDID).

branches: 1.10.4; 1.10.6; 1.10.10;
Ignore errors on some rm -rf's for platforms that aren't quite
POSIX compliant
and return errors on r/o source (FreeBSD) for -rf. Fixes PR#25022

branches: 1.9.2;
Use ${HOST_SH} instead of `sh'.

If necessary, pull in <bsd.sys.mk> to get the definition of HOST_SH;
Makefiles that pull in one of (most of) <bsd.*.mk> will get this anyway.

branches: 1.8.2;
* Add ${PROGSYM} to CLEANFILES.
* Instsall either the .bin or the .sym, based on whether or not
the resulting gzboot needs to be mdsetimage'd.

Also build a flat binary version of the gzboot program.

Garbage-collect the DYNAMIC_CRC_TABLE stuff. The table it computed
was incompatible with the new CRC code, and it is largely unnecessary
now, since the static table is so much smaller.

Fixes PR kern/20935.

branches: 1.5.6;
Give gzboot a 1M heap, so that loading gzip -9'd kernels works
reliably.

branches: 1.4.2;
Add support for relocating gzboot's .text out of flash and into
RAM (while still decompressing the image directly from flash).

This makes gzboot run a LOT faster.

Fix the -DRELOC=... CPP flag. Add -DDYNAMIC_CRC_TABLE to shrink
the text (and, thus, the space taken up in flash) a bit.

Add support for running directly out of flash:
* Require that the builder Makefile provide a linker script.
* After making sure the MMU is disabled, check to see if
_etext == __data_start. If not, then copy the .data contents
into RAM.
* Put the stack in .bss.

gzboot -- boot a gzip'd kernel image. This is useful for booting
compressed kernel images from flash.

This needs more work, but is a good first-pass.

centralize vers.c building for standalone programs.

GC more logic that was intended for GCC <4.8 (or !LLVM)

Same as before (-marm implies -mno-thumb), but now the condition was flipped

branches: 1.34.2; 1.34.4;
Don't reuse LDFLAGS for arguments passed directly to ${LD}, share/mk
expects it to be passed to ${CC} or ${CXX}, so they will generally
prefix flags with -Wl.

remove the MKPIE and MKCTF no hack, and move it to the .mk files

Disable PIE and CTF for standalone code
XXX: Must be done centrally, and there must be a better way.

Clear STRIPFLAGS (stripping in general is dangerous with the -BE8 object
format, and should never be done before the final linking has happened).
From Rin Okuyama.

branches: 1.30.6;
Add empty LIBCRTI= as LIBCRT0 to build sa programs without installed DESTDIR.

XXX: probabry we should have bsd.saprog.mk or something.

Move flags for ARM's APCS ABI into a common variable. Add some forces to
deal with limitations in the Clang <-> LLVM backend interaction to pick
the correct ABI and target assembler.

Use -marm for clang builds, too.

explicitly add -marm

-mno-thumb-interwork is the default, and there is no -mthumb in gcc 4.8

Use <bsd.klinks.mk>

Add CPPFLAGS+= -mno-thumb -mno-thumb-interwork

branches: 1.23.2;
Add -fno-unwind-tables

gcc will supply -Wa,-eabi=gnu so don't include. Use -mabi=apcs-base, not atpcs

Make sure these are always compiled with -mabi=atpcs -mfloat-abi=soft
-Wa,-meabi=gnu so they use the old compilation methods.

branches: 1.20.2;
Fixed build with USE_SSP=yes

ok christos@

Fix to allow EABI compilation.
Make sure to DISCARD new .ARM.attributes and .ARM.ebxidx sections.

Add missing ${_MKTARGET_LINK}

branches: 1.17.4; 1.17.10;
Drop bootprog_maker (formerly enabled by -M) and bootprog_date (formerly
disabled by -D) from the output of newvers_stand.sh. Change -D to the
inverted logic, so that it adds the date to bootprog_rev in ().

Change all platforms accordingly. -D is added if MKREPRO is not yes and
wasn't present before. Platforms that didn't use -D don't depend on
MKREPRO now either.

branches: 1.16.2; 1.16.4;
Introduce .WAIT into the cleandir rule for blasting the libsa/libkern/etc.
trees, because it can race with the libsa/libkern/etc. makefiles' own
cleandir rules. I think I've found all of the uses of the offending idiom...
Closes PR 43360.

branches: 1.15.4; 1.15.6;
- WARNSfy
- add src/common/dist/zlib to incpath for build without DESTDIR

branches: 1.14.72; 1.14.76; 1.14.84;
The new zlib uses HEAP_SIZE, so instead use BOARD_HEAP_SIZE as the
symbol to use here. Also adapt to the new zlib with the changed name
for the header file.

branches: 1.13.2;
merge ktrace-lwp.

branches: 1.12.2;
dependencies for .BEGIN is not accepted by the latest nbmake.

include <bsd.obj.mk> to teach make the rules for OBJDIR names.

This is to fix a problem on compiling gzboot with BUILDID defined
(by build.sh -B BUILDID).

branches: 1.10.4; 1.10.6; 1.10.10;
Ignore errors on some rm -rf's for platforms that aren't quite
POSIX compliant
and return errors on r/o source (FreeBSD) for -rf. Fixes PR#25022

branches: 1.9.2;
Use ${HOST_SH} instead of `sh'.

If necessary, pull in <bsd.sys.mk> to get the definition of HOST_SH;
Makefiles that pull in one of (most of) <bsd.*.mk> will get this anyway.

branches: 1.8.2;
* Add ${PROGSYM} to CLEANFILES.
* Instsall either the .bin or the .sym, based on whether or not
the resulting gzboot needs to be mdsetimage'd.

Also build a flat binary version of the gzboot program.

Garbage-collect the DYNAMIC_CRC_TABLE stuff. The table it computed
was incompatible with the new CRC code, and it is largely unnecessary
now, since the static table is so much smaller.

Fixes PR kern/20935.

branches: 1.5.6;
Give gzboot a 1M heap, so that loading gzip -9'd kernels works
reliably.

branches: 1.4.2;
Add support for relocating gzboot's .text out of flash and into
RAM (while still decompressing the image directly from flash).

This makes gzboot run a LOT faster.

Fix the -DRELOC=... CPP flag. Add -DDYNAMIC_CRC_TABLE to shrink
the text (and, thus, the space taken up in flash) a bit.

Add support for running directly out of flash:
* Require that the builder Makefile provide a linker script.
* After making sure the MMU is disabled, check to see if
_etext == __data_start. If not, then copy the .data contents
into RAM.
* Put the stack in .bss.

gzboot -- boot a gzip'd kernel image. This is useful for booting
compressed kernel images from flash.

This needs more work, but is a good first-pass.

GC more logic that was intended for GCC <4.8 (or !LLVM)

Same as before (-marm implies -mno-thumb), but now the condition was flipped

Don't reuse LDFLAGS for arguments passed directly to ${LD}, share/mk
expects it to be passed to ${CC} or ${CXX}, so they will generally
prefix flags with -Wl.

remove the MKPIE and MKCTF no hack, and move it to the .mk files

Disable PIE and CTF for standalone code
XXX: Must be done centrally, and there must be a better way.

Clear STRIPFLAGS (stripping in general is dangerous with the -BE8 object
format, and should never be done before the final linking has happened).
From Rin Okuyama.

branches: 1.30.6;
Add empty LIBCRTI= as LIBCRT0 to build sa programs without installed DESTDIR.

XXX: probabry we should have bsd.saprog.mk or something.

Move flags for ARM's APCS ABI into a common variable. Add some forces to
deal with limitations in the Clang <-> LLVM backend interaction to pick
the correct ABI and target assembler.

Use -marm for clang builds, too.

explicitly add -marm

-mno-thumb-interwork is the default, and there is no -mthumb in gcc 4.8

Use <bsd.klinks.mk>

Add CPPFLAGS+= -mno-thumb -mno-thumb-interwork

branches: 1.23.2;
Add -fno-unwind-tables

gcc will supply -Wa,-eabi=gnu so don't include. Use -mabi=apcs-base, not atpcs

Make sure these are always compiled with -mabi=atpcs -mfloat-abi=soft
-Wa,-meabi=gnu so they use the old compilation methods.

branches: 1.20.2;
Fixed build with USE_SSP=yes

ok christos@

Fix to allow EABI compilation.
Make sure to DISCARD new .ARM.attributes and .ARM.ebxidx sections.

Add missing ${_MKTARGET_LINK}

branches: 1.17.4; 1.17.10;
Drop bootprog_maker (formerly enabled by -M) and bootprog_date (formerly
disabled by -D) from the output of newvers_stand.sh. Change -D to the
inverted logic, so that it adds the date to bootprog_rev in ().

Change all platforms accordingly. -D is added if MKREPRO is not yes and
wasn't present before. Platforms that didn't use -D don't depend on
MKREPRO now either.

branches: 1.16.2; 1.16.4;
Introduce .WAIT into the cleandir rule for blasting the libsa/libkern/etc.
trees, because it can race with the libsa/libkern/etc. makefiles' own
cleandir rules. I think I've found all of the uses of the offending idiom...
Closes PR 43360.

branches: 1.15.4; 1.15.6;
- WARNSfy
- add src/common/dist/zlib to incpath for build without DESTDIR

branches: 1.14.72; 1.14.76; 1.14.84;
The new zlib uses HEAP_SIZE, so instead use BOARD_HEAP_SIZE as the
symbol to use here. Also adapt to the new zlib with the changed name
for the header file.

branches: 1.13.2;
merge ktrace-lwp.

branches: 1.12.2;
dependencies for .BEGIN is not accepted by the latest nbmake.

include <bsd.obj.mk> to teach make the rules for OBJDIR names.

This is to fix a problem on compiling gzboot with BUILDID defined
(by build.sh -B BUILDID).

branches: 1.10.4; 1.10.6; 1.10.10;
Ignore errors on some rm -rf's for platforms that aren't quite
POSIX compliant
and return errors on r/o source (FreeBSD) for -rf. Fixes PR#25022

branches: 1.9.2;
Use ${HOST_SH} instead of `sh'.

If necessary, pull in <bsd.sys.mk> to get the definition of HOST_SH;
Makefiles that pull in one of (most of) <bsd.*.mk> will get this anyway.

branches: 1.8.2;
* Add ${PROGSYM} to CLEANFILES.
* Instsall either the .bin or the .sym, based on whether or not
the resulting gzboot needs to be mdsetimage'd.

Also build a flat binary version of the gzboot program.

Garbage-collect the DYNAMIC_CRC_TABLE stuff. The table it computed
was incompatible with the new CRC code, and it is largely unnecessary
now, since the static table is so much smaller.

Fixes PR kern/20935.

branches: 1.5.6;
Give gzboot a 1M heap, so that loading gzip -9'd kernels works
reliably.

branches: 1.4.2;
Add support for relocating gzboot's .text out of flash and into
RAM (while still decompressing the image directly from flash).

This makes gzboot run a LOT faster.

Fix the -DRELOC=... CPP flag. Add -DDYNAMIC_CRC_TABLE to shrink
the text (and, thus, the space taken up in flash) a bit.

Add support for running directly out of flash:
* Require that the builder Makefile provide a linker script.
* After making sure the MMU is disabled, check to see if
_etext == __data_start. If not, then copy the .data contents
into RAM.
* Put the stack in .bss.

gzboot -- boot a gzip'd kernel image. This is useful for booting
compressed kernel images from flash.

This needs more work, but is a good first-pass.

Don't reuse LDFLAGS for arguments passed directly to ${LD}, share/mk
expects it to be passed to ${CC} or ${CXX}, so they will generally
prefix flags with -Wl.

remove the MKPIE and MKCTF no hack, and move it to the .mk files

Disable PIE and CTF for standalone code
XXX: Must be done centrally, and there must be a better way.

Clear STRIPFLAGS (stripping in general is dangerous with the -BE8 object
format, and should never be done before the final linking has happened).
From Rin Okuyama.

branches: 1.30.6;
Add empty LIBCRTI= as LIBCRT0 to build sa programs without installed DESTDIR.

XXX: probabry we should have bsd.saprog.mk or something.

Move flags for ARM's APCS ABI into a common variable. Add some forces to
deal with limitations in the Clang <-> LLVM backend interaction to pick
the correct ABI and target assembler.

Use -marm for clang builds, too.

explicitly add -marm

-mno-thumb-interwork is the default, and there is no -mthumb in gcc 4.8

Use <bsd.klinks.mk>

Add CPPFLAGS+= -mno-thumb -mno-thumb-interwork

branches: 1.23.2;
Add -fno-unwind-tables

gcc will supply -Wa,-eabi=gnu so don't include. Use -mabi=apcs-base, not atpcs

Make sure these are always compiled with -mabi=atpcs -mfloat-abi=soft
-Wa,-meabi=gnu so they use the old compilation methods.

branches: 1.20.2;
Fixed build with USE_SSP=yes

ok christos@

Fix to allow EABI compilation.
Make sure to DISCARD new .ARM.attributes and .ARM.ebxidx sections.

Add missing ${_MKTARGET_LINK}

branches: 1.17.4; 1.17.10;
Drop bootprog_maker (formerly enabled by -M) and bootprog_date (formerly
disabled by -D) from the output of newvers_stand.sh. Change -D to the
inverted logic, so that it adds the date to bootprog_rev in ().

Change all platforms accordingly. -D is added if MKREPRO is not yes and
wasn't present before. Platforms that didn't use -D don't depend on
MKREPRO now either.

branches: 1.16.2; 1.16.4;
Introduce .WAIT into the cleandir rule for blasting the libsa/libkern/etc.
trees, because it can race with the libsa/libkern/etc. makefiles' own
cleandir rules. I think I've found all of the uses of the offending idiom...
Closes PR 43360.

branches: 1.15.4; 1.15.6;
- WARNSfy
- add src/common/dist/zlib to incpath for build without DESTDIR

branches: 1.14.72; 1.14.76; 1.14.84;
The new zlib uses HEAP_SIZE, so instead use BOARD_HEAP_SIZE as the
symbol to use here. Also adapt to the new zlib with the changed name
for the header file.

branches: 1.13.2;
merge ktrace-lwp.

branches: 1.12.2;
dependencies for .BEGIN is not accepted by the latest nbmake.

include <bsd.obj.mk> to teach make the rules for OBJDIR names.

This is to fix a problem on compiling gzboot with BUILDID defined
(by build.sh -B BUILDID).

branches: 1.10.4; 1.10.6; 1.10.10;
Ignore errors on some rm -rf's for platforms that aren't quite
POSIX compliant
and return errors on r/o source (FreeBSD) for -rf. Fixes PR#25022

branches: 1.9.2;
Use ${HOST_SH} instead of `sh'.

If necessary, pull in <bsd.sys.mk> to get the definition of HOST_SH;
Makefiles that pull in one of (most of) <bsd.*.mk> will get this anyway.

branches: 1.8.2;
* Add ${PROGSYM} to CLEANFILES.
* Instsall either the .bin or the .sym, based on whether or not
the resulting gzboot needs to be mdsetimage'd.

Also build a flat binary version of the gzboot program.

Garbage-collect the DYNAMIC_CRC_TABLE stuff. The table it computed
was incompatible with the new CRC code, and it is largely unnecessary
now, since the static table is so much smaller.

Fixes PR kern/20935.

branches: 1.5.6;
Give gzboot a 1M heap, so that loading gzip -9'd kernels works
reliably.

branches: 1.4.2;
Add support for relocating gzboot's .text out of flash and into
RAM (while still decompressing the image directly from flash).

This makes gzboot run a LOT faster.

Fix the -DRELOC=... CPP flag. Add -DDYNAMIC_CRC_TABLE to shrink
the text (and, thus, the space taken up in flash) a bit.

Add support for running directly out of flash:
* Require that the builder Makefile provide a linker script.
* After making sure the MMU is disabled, check to see if
_etext == __data_start. If not, then copy the .data contents
into RAM.
* Put the stack in .bss.

gzboot -- boot a gzip'd kernel image. This is useful for booting
compressed kernel images from flash.

This needs more work, but is a good first-pass.