diff options
| author | Jonas Gorski | 2015-04-12 12:24:59 +0200 |
|---|---|---|
| committer | Ralf Baechle | 2015-06-21 21:54:15 +0200 |
| commit | c0b4e101443c637f3e57d4263c5af4e2a0afa867 (patch) | |
| tree | 4ba68994b21a0ab36ba790a8b5dd6cf72bfd8725 /arch/mips | |
| parent | 1da8f1798e307fb8422753984339beb00025f97d (diff) | |
MIPS: Add support for vmlinuz.bin appended dtb
Add support for detecting a vmlinuz.bin appended dtb and overriding
the boot arguments to match the UHI interface.
To ensure _edata / __apendend_dtb points to the actual end of the
binary, align the data section to 16 bytes instead of the address
cursor.
Due to ld.script not going through the preprocessor, we can't check
for MIPS_ZBOOT_APPENDED_DTB being enabled, so always reserve space
for it. It should have no consequences for booting without it enabled
except 1 MiB more ram usage during the uncompressing stage.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: John Crispin <blogic@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hartley <James.Hartley@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9741/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/Kconfig | 18 | ||||
| -rw-r--r-- | arch/mips/boot/compressed/head.S | 16 | ||||
| -rw-r--r-- | arch/mips/boot/compressed/ld.script | 6 |
3 files changed, 39 insertions, 1 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 7cb5f6dbaeee..a2ee09c8056f 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -2702,6 +2702,24 @@ choice look like a DTB header after a reboot if no actual DTB is appended to vmlinux.bin. Do not leave this option active in a production kernel if you don't intend to always append a DTB. + + config MIPS_ZBOOT_APPENDED_DTB + bool "vmlinuz.bin" + depends on SYS_SUPPORTS_ZBOOT + help + With this option, the boot code will look for a device tree binary + DTB) appended to raw vmlinuz.bin (with decompressor). + (e.g. cat vmlinuz.bin <filename>.dtb > vmlinuz_w_dtb). + + This is meant as a backward compatibility convenience for those + systems with a bootloader that can't be upgraded to accommodate + the documented boot protocol using a device tree. + + Beware that there is very little in terms of protection against + this option being confused by leftover garbage in memory that might + look like a DTB header after a reboot if no actual DTB is appended + to vmlinuz.bin. Do not leave this option active in a production kernel + if you don't intend to always append a DTB. endchoice endmenu diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S index 409cb483a9ff..c580e853b9fb 100644 --- a/arch/mips/boot/compressed/head.S +++ b/arch/mips/boot/compressed/head.S @@ -25,6 +25,22 @@ start: move s2, a2 move s3, a3 +#ifdef CONFIG_MIPS_ZBOOT_APPENDED_DTB + PTR_LA t0, __appended_dtb +#ifdef CONFIG_CPU_BIG_ENDIAN + li t1, 0xd00dfeed +#else + li t1, 0xedfe0dd0 +#endif + lw t2, (t0) + bne t1, t2, not_found + nop + + move s1, t0 + PTR_LI s0, -2 +not_found: +#endif + /* Clear BSS */ PTR_LA a0, _edata PTR_LA a2, _end diff --git a/arch/mips/boot/compressed/ld.script b/arch/mips/boot/compressed/ld.script index 5a33409c7f63..2ed08fbef8e7 100644 --- a/arch/mips/boot/compressed/ld.script +++ b/arch/mips/boot/compressed/ld.script @@ -29,8 +29,12 @@ SECTIONS *(.image) __image_end = .; CONSTRUCTORS + . = ALIGN(16); } - . = ALIGN(16); + __appended_dtb = .; + /* leave space for appended DTB */ + . += 0x100000; + _edata = .; /* End of data section */ |