diff options
| author | Max Filippov <jcmvbkbc@gmail.com> | 2017-01-03 17:57:51 -0800 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2019-11-26 11:33:38 -0800 |
| commit | 7af710d988775aadf440222ecbe0c10eecf3eb54 (patch) | |
| tree | f499a51c705441d0aa2019ef88f13e8598627b92 /arch/xtensa/include | |
| parent | 76743c0e0915af6ae1d960c14e8c1dcb3e238f23 (diff) | |
| download | linux-7af710d988775aadf440222ecbe0c10eecf3eb54.tar.gz | |
xtensa: add XIP kernel support
XIP (eXecute In Place) kernel image is the image that can be run
directly from ROM, using RAM only for writable data.
XIP xtensa kernel differs from regular xtensa kernel in the following
ways:
- it has exception/IRQ vectors merged into text section. No vectors
relocation takes place at kernel startup.
- .data/.bss location must be specified in the kernel configuration,
its content is copied there in the _startup function.
- .init.text is merged with the rest of text and is executed from ROM.
- when MMU is used the virtual address where the kernel will be mapped
must be specified in the kernel configuration. It may be in the KSEG
or in the KIO, __pa macro is adjusted to be able to handle both.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/include')
| -rw-r--r-- | arch/xtensa/include/asm/cache.h | 6 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/page.h | 11 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/vectors.h | 4 |
3 files changed, 21 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/cache.h b/arch/xtensa/include/asm/cache.h index b21fd133ff62..54e147ac26bf 100644 --- a/arch/xtensa/include/asm/cache.h +++ b/arch/xtensa/include/asm/cache.h @@ -31,4 +31,10 @@ #define ARCH_DMA_MINALIGN L1_CACHE_BYTES +/* + * R/O after init is actually writable, it cannot go to .rodata + * according to vmlinux linker script. + */ +#define __ro_after_init __read_mostly + #endif /* _XTENSA_CACHE_H */ diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h index 09c56cba442e..f4771c29c7e9 100644 --- a/arch/xtensa/include/asm/page.h +++ b/arch/xtensa/include/asm/page.h @@ -169,7 +169,18 @@ static inline unsigned long ___pa(unsigned long va) if (off >= XCHAL_KSEG_SIZE) off -= XCHAL_KSEG_SIZE; +#ifndef CONFIG_XIP_KERNEL return off + PHYS_OFFSET; +#else + if (off < XCHAL_KSEG_SIZE) + return off + PHYS_OFFSET; + + off -= XCHAL_KSEG_SIZE; + if (off >= XCHAL_KIO_SIZE) + off -= XCHAL_KIO_SIZE; + + return off + XCHAL_KIO_PADDR; +#endif } #define __pa(x) ___pa((unsigned long)(x)) #else diff --git a/arch/xtensa/include/asm/vectors.h b/arch/xtensa/include/asm/vectors.h index 4220c6dac44f..fd99b25037a7 100644 --- a/arch/xtensa/include/asm/vectors.h +++ b/arch/xtensa/include/asm/vectors.h @@ -22,9 +22,13 @@ #include <asm/kmem_layout.h> #if defined(CONFIG_MMU) && XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY +#ifdef CONFIG_KERNEL_VIRTUAL_ADDRESS +#define KERNELOFFSET CONFIG_KERNEL_VIRTUAL_ADDRESS +#else #define KERNELOFFSET (CONFIG_KERNEL_LOAD_ADDRESS + \ XCHAL_KSEG_CACHED_VADDR - \ XCHAL_KSEG_PADDR) +#endif #else #define KERNELOFFSET CONFIG_KERNEL_LOAD_ADDRESS #endif |