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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2012-07-04 04:58:12 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-07-09 17:39:39 +0100 |
| commit | 9fa16b7755967b1b4dc704de71a3d639d13e21fc (patch) | |
| tree | e3686faa439a42294e48f067ed26848a39f23530 /arch/arm/kernel/head.S | |
| parent | d0f34a11ddab9b456e4caf9fc48d8d7e832e0e50 (diff) | |
| download | linux-9fa16b7755967b1b4dc704de71a3d639d13e21fc.tar.gz linux-9fa16b7755967b1b4dc704de71a3d639d13e21fc.tar.bz2 linux-9fa16b7755967b1b4dc704de71a3d639d13e21fc.zip | |
ARM: 7439/1: head.S: simplify initial page table mapping
Let's map the initial RAM up to the end of the kernel .bss instead of
the strict kernel image area. This simplifies the code as the kernel
image only needs to be handled specially in the XIP case. That covers
the legacy ATAG location as well.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/head.S')
| -rw-r--r-- | arch/arm/kernel/head.S | 59 |
1 files changed, 23 insertions, 36 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 835898e7d704..3db960e20cb8 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -55,14 +55,6 @@ add \rd, \phys, #TEXT_OFFSET - PG_DIR_SIZE .endm -#ifdef CONFIG_XIP_KERNEL -#define KERNEL_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) -#define KERNEL_END _edata_loc -#else -#define KERNEL_START KERNEL_RAM_VADDR -#define KERNEL_END _end -#endif - /* * Kernel startup entry point. * --------------------------- @@ -218,51 +210,46 @@ __create_page_tables: blo 1b /* - * Now setup the pagetables for our kernel direct - * mapped region. + * Map our RAM from the start to the end of the kernel .bss section. */ - mov r3, pc - mov r3, r3, lsr #SECTION_SHIFT - orr r3, r7, r3, lsl #SECTION_SHIFT - add r0, r4, #(KERNEL_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) - str r3, [r0, #((KERNEL_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]! - ldr r6, =(KERNEL_END - 1) - add r0, r0, #1 << PMD_ORDER + add r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER) + ldr r6, =(_end - 1) + orr r3, r8, r7 add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) -1: cmp r0, r6 +1: str r3, [r0], #1 << PMD_ORDER add r3, r3, #1 << SECTION_SHIFT - strls r3, [r0], #1 << PMD_ORDER + cmp r0, r6 bls 1b #ifdef CONFIG_XIP_KERNEL /* - * Map some ram to cover our .data and .bss areas. + * Map the kernel image separately as it is not located in RAM. */ - add r3, r8, #TEXT_OFFSET - orr r3, r3, r7 - add r0, r4, #(KERNEL_RAM_VADDR & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) - str r3, [r0, #(KERNEL_RAM_VADDR & 0x00f00000) >> (SECTION_SHIFT - PMD_ORDER)]! - ldr r6, =(_end - 1) - add r0, r0, #4 +#define XIP_START XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR) + mov r3, pc + mov r3, r3, lsr #SECTION_SHIFT + orr r3, r7, r3, lsl #SECTION_SHIFT + add r0, r4, #(XIP_START & 0xff000000) >> (SECTION_SHIFT - PMD_ORDER) + str r3, [r0, #((XIP_START & 0x00f00000) >> SECTION_SHIFT) << PMD_ORDER]! + ldr r6, =(_edata_loc - 1) + add r0, r0, #1 << PMD_ORDER add r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER) 1: cmp r0, r6 - add r3, r3, #1 << 20 - strls r3, [r0], #4 + add r3, r3, #1 << SECTION_SHIFT + strls r3, [r0], #1 << PMD_ORDER bls 1b #endif /* - * Then map boot params address in r2 or the first 1MB (2MB with LPAE) - * of ram if boot params address is not specified. + * Then map boot params address in r2 if specified. */ mov r0, r2, lsr #SECTION_SHIFT movs r0, r0, lsl #SECTION_SHIFT - moveq r0, r8 - sub r3, r0, r8 - add r3, r3, #PAGE_OFFSET - add r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) - orr r6, r7, r0 - str r6, [r3] + subne r3, r0, r8 + addne r3, r3, #PAGE_OFFSET + addne r3, r4, r3, lsr #(SECTION_SHIFT - PMD_ORDER) + orrne r6, r7, r0 + strne r6, [r3] #ifdef CONFIG_DEBUG_LL #if !defined(CONFIG_DEBUG_ICEDCC) && !defined(CONFIG_DEBUG_SEMIHOSTING) |