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| author |   Linus Walleij <linus.walleij@linaro.org> | 2021-06-03 09:50:16 +0100 |
|---|---|---|
| committer |   Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2021-06-13 18:16:40 +0100 |
| commit | b78f63f4439bbfd02bfc628114ed0f63460e5570 (patch) | |
| tree | f78e13f3faf09f44c6a35c76925854e18344898e /arch | |
| parent | ARM: 9087/1: kprobes: test-thumb: fix for LLVM_IAS=1 (diff) | |
| download | linux-dev-b78f63f4439bbfd02bfc628114ed0f63460e5570.tar.xz linux-dev-b78f63f4439bbfd02bfc628114ed0f63460e5570.zip | |
ARM: 9088/1: Split KERNEL_OFFSET from PAGE_OFFSET
We want to be able to compile the kernel into an address different
from PAGE_OFFSET (start of lowmem) + TEXT_OFFSET, so start to pry
apart the address of where the kernel is located from the address
where the lowmem is located by defining and using KERNEL_OFFSET in
a few key places.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/memory.h | 8 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/vmlinux.lds.S | 2 |
3 files changed, 9 insertions, 4 deletions
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index a711322d9f40..a5f1d1826a98 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -20,8 +20,14 @@ #endif #include <asm/kasan_def.h> -/* PAGE_OFFSET - the virtual address of the start of the kernel image */ +/* + * PAGE_OFFSET: the virtual address of the start of lowmem, memory above + * the virtual address range for userspace. + * KERNEL_OFFSET: the virtual address of the start of the kernel image. + * we may further offset this with TEXT_OFFSET in practice. + */ #define PAGE_OFFSET UL(CONFIG_PAGE_OFFSET) +#define KERNEL_OFFSET (PAGE_OFFSET) #ifdef CONFIG_MMU diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 7f62c5eccdf3..4e2daaa7636a 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -23,7 +23,6 @@ #if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING) #include CONFIG_DEBUG_LL_INCLUDE #endif - /* * swapper_pg_dir is the virtual address of the initial page table. * We place the page tables 16K below KERNEL_RAM_VADDR. Therefore, we must @@ -31,7 +30,7 @@ * the least significant 16 bits to be 0x8000, but we could probably * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000. */ -#define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET) +#define KERNEL_RAM_VADDR (KERNEL_OFFSET + TEXT_OFFSET) #if (KERNEL_RAM_VADDR & 0xffff) != 0x8000 #error KERNEL_RAM_VADDR must start at 0xXXXX8000 #endif diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index f7f4620d59c3..20c4f6d20c7a 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -47,7 +47,7 @@ SECTIONS #endif } - . = PAGE_OFFSET + TEXT_OFFSET; + . = KERNEL_OFFSET + TEXT_OFFSET; .head.text : { _text = .; HEAD_TEXT |