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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 21:50:35 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 21:50:35 +0100 |
commit | 441692aafc1731087bbaf657a8b6059d95c2a6df (patch) | |
tree | 9d3dd6d6e882bc9bb69e3389715b720ee9001ead /arch/arm/kernel/head-inflate-data.c | |
parent | Merge tag 'powerpc-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/p... (diff) | |
parent | Merge branch 'devel-stable' into for-next (diff) | |
download | linux-441692aafc1731087bbaf657a8b6059d95c2a6df.tar.xz linux-441692aafc1731087bbaf657a8b6059d95c2a6df.zip |
Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM updates from Russell King:
- add support for ELF fdpic binaries on both MMU and noMMU platforms
- linker script cleanups
- support for compressed .data section for XIP images
- discard memblock arrays when possible
- various cleanups
- atomic DMA pool updates
- better diagnostics of missing/corrupt device tree
- export information to allow userspace kexec tool to place images more
inteligently, so that the device tree isn't overwritten by the
booting kernel
- make early_printk more efficient on semihosted systems
- noMMU cleanups
- SA1111 PCMCIA update in preparation for further cleanups
* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (38 commits)
ARM: 8719/1: NOMMU: work around maybe-uninitialized warning
ARM: 8717/2: debug printch/printascii: translate '\n' to "\r\n" not "\n\r"
ARM: 8713/1: NOMMU: Support MPU in XIP configuration
ARM: 8712/1: NOMMU: Use more MPU regions to cover memory
ARM: 8711/1: V7M: Add support for MPU to M-class
ARM: 8710/1: Kconfig: Kill CONFIG_VECTORS_BASE
ARM: 8709/1: NOMMU: Disallow MPU for XIP
ARM: 8708/1: NOMMU: Rework MPU to be mostly done in C
ARM: 8707/1: NOMMU: Update MPU accessors to use cp15 helpers
ARM: 8706/1: NOMMU: Move out MPU setup in separate module
ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel()
ARM: 8705/1: early_printk: use printascii() rather than printch()
ARM: 8703/1: debug.S: move hexbuf to a writable section
ARM: add additional table to compressed kernel
ARM: decompressor: fix BSS size calculation
pcmcia: sa1111: remove special sa1111 mmio accessors
pcmcia: sa1111: use sa1111_get_irq() to obtain IRQ resources
ARM: better diagnostics with missing/corrupt dtb
ARM: 8699/1: dma-mapping: Remove init_dma_coherent_pool_size()
ARM: 8698/1: dma-mapping: Mark atomic_pool as __ro_after_init
..
Diffstat (limited to 'arch/arm/kernel/head-inflate-data.c')
-rw-r--r-- | arch/arm/kernel/head-inflate-data.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/arm/kernel/head-inflate-data.c b/arch/arm/kernel/head-inflate-data.c new file mode 100644 index 000000000000..6dd0ce5e6058 --- /dev/null +++ b/arch/arm/kernel/head-inflate-data.c @@ -0,0 +1,62 @@ +/* + * XIP kernel .data segment decompressor + * + * Created by: Nicolas Pitre, August 2017 + * Copyright: (C) 2017 Linaro Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/init.h> +#include <linux/zutil.h> + +/* for struct inflate_state */ +#include "../../../lib/zlib_inflate/inftrees.h" +#include "../../../lib/zlib_inflate/inflate.h" +#include "../../../lib/zlib_inflate/infutil.h" + +extern char __data_loc[]; +extern char _edata_loc[]; +extern char _sdata[]; + +/* + * This code is called very early during the boot process to decompress + * the .data segment stored compressed in ROM. Therefore none of the global + * variables are valid yet, hence no kernel services such as memory + * allocation is available. Everything must be allocated on the stack and + * we must avoid any global data access. We use a temporary stack located + * in the .bss area. The linker script makes sure the .bss is big enough + * to hold our stack frame plus some room for called functions. + * + * We mimic the code in lib/decompress_inflate.c to use the smallest work + * area possible. And because everything is statically allocated on the + * stack then there is no need to clean up before returning. + */ + +int __init __inflate_kernel_data(void) +{ + struct z_stream_s stream, *strm = &stream; + struct inflate_state state; + char *in = __data_loc; + int rc; + + /* Check and skip gzip header (assume no filename) */ + if (in[0] != 0x1f || in[1] != 0x8b || in[2] != 0x08 || in[3] & ~3) + return -1; + in += 10; + + strm->workspace = &state; + strm->next_in = in; + strm->avail_in = _edata_loc - __data_loc; /* upper bound */ + strm->next_out = _sdata; + strm->avail_out = _edata_loc - __data_loc; + zlib_inflateInit2(strm, -MAX_WBITS); + WS(strm)->inflate_state.wsize = 0; + WS(strm)->inflate_state.window = NULL; + rc = zlib_inflate(strm, Z_FINISH); + if (rc == Z_OK || rc == Z_STREAM_END) + rc = strm->avail_out; /* should be 0 */ + return rc; +} |