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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2865 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2010-08-18 16:15:37 +00:00
parent f3f0bcd20a
commit 8541920c2e
2 changed files with 45 additions and 12 deletions
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55
arch/arm/src/arm/up_head.S
View File

@ -164,26 +164,30 @@ __start:
teq r0, r2
bne .Lpgtableclear
/* Create identity mapping for first MB section to support this startup
* logic executing out of the physical address space. This identity
* mapping will be removed by .Lvstart (see below).
/* Create identity mapping for first MB of the .text section to support
* this startup logic executing out of the physical address space. This
* identity mapping will be removed by .Lvstart (see below).
*/
#warning "We need to do things differently here if the .text region is smaller or if CONFIG_PAGING"
mksection r0, r4 /* r0=phys. base section */
ldr r1, .LCmmuflags /* FLGS=MMU_MEMFLAGS */
add r3, r1, r0 /* r3=flags + base */
str r3, [r4, r0, lsr #18] /* identity mapping */
/* Create a "normal" single section mapping for the first
* MB of memory. Now, we have the first 1MB mapping to
* both phyical and virtual addresses. The reset of the
* SDRAM mapping will be completed in .Lvstart once we have
* moved the physical mapping out of the way.
/* Create a virtual single section mapping for the first MB of the .text
* address space. Now, we have the first 1MB mapping to both phyical and
* virtual addresses. The rest of the .text mapping will be completed in
* .Lvstart once we have moved the physical mapping out of the way.
*/
ldr r2, .LCvpgtable /* r2=virt. page table */
mksection r0, r2 /* r0=virt. base section */
str r3, [r4, r0, lsr #18] /* identity mapping */
/* NOTE: No .data/.bss access should be attempted. This temporary mapping
* can only be assumed to cover the initial .text region.
*/
#endif /* CONFIG_ARCH_ROMPGTABLE */
/* The following logic will set up the ARM920/ARM926 for normal operation */
@ -316,7 +320,10 @@ __start:
.type .Lvstart, %function
.Lvstart:
/* Remove the temporary null mapping */
/* Remove the temporary mapping. The following assumes that the
* total RAM size is > 1Mb and extends that initial mapping to
* cover additinal RAM sections.
*/
#ifndef CONFIG_ARCH_ROMPGTABLE
ldr r4, .LCvpgtable /* r4=virtual page table */
@ -328,7 +335,7 @@ __start:
/* Now setup the pagetables for our normal SDRAM mappings mapped region.
* We round NUTTX_START_VADDR down to the nearest megabyte boundary.
*/
#warning "We need to do things differently here if the .text region is smaller or if CONFIG_PAGING"
ldr r1, .LCmmuflags /* FLGS=MMU_MEMFLAGS */
add r3, r3, r1 /* r3=flags + base */
@ -347,6 +354,19 @@ __start:
add r3, r3, #SECTION_SIZE
str r3, [r0], #4
.endr
/* If we are executing from RAM with a fixed page configuration, then
* we can assume that the above contiguous mapping included all of the
* .text, .data, .bss, heap, etc. But if we are executing from FLASH,
* then the RAM area is probably in a separate physical address region
* and will require a separate mapping. Or, if we are supporting on-demand
* paging of the .text region, then the RAM-based .data/.bss/heap section
* will still probably be located in a separate (virtual) address region.
*/
#if defined(CONFIG_BOOT_RUNFROMFLASH) || defined(CONFIG_PAGING)
# error "Logic not implemented"
#endif
#endif /* CONFIG_ARCH_ROMPGTABLE */
/* Zero BSS and set up the stack pointer */
@ -363,6 +383,19 @@ __start:
strcc fp, [r0],#4
bcc .Lbssinit
/* If the .data section is in a separate, unitialized address space,
* then we will also need to copy the initial values of of the .data
* section from the .text region into that .data region. This would
* be the case if we are executing from FLASH and the .data section
* lies in a different physical address region OR if we are support
* on-demand paging and the .data section lies in a different virtual
* address region.
*/
#if defined(CONFIG_BOOT_RUNFROMFLASH) || defined(CONFIG_PAGING)
# error "Logic not implemented"
#endif
/* Perform early C-level, platform-specific initialization */
bl up_boot

2
arch/arm/src/lpc313x/lpc313x_boot.c
View File

@ -269,7 +269,7 @@ static void up_copyvectorblock(void)
void up_boot(void)
{
/* __start provided the basic MMU mappings for SDRAM. Now provide mappings for all
/* __start provided the basic MMU mappings for SRAM. Now provide mappings for all
* IO regions (Including the vector region).
*/