michaelh/zephyr
1
0
Fork 0
Code Releases Activity

x86: add CONFIG_X86_KERNEL_OFFSET

Browse source 
Previously, DTS specification of physical RAM bounds did not
correspond to the actual bounds of system RAM as the first
megabyte was being skipped.

There were reasons for this - the first 1MB on PC-like systems
is a no-man's-land of reserved memory regions, but we need DTS
to accurately capture physical memory bounds.

Instead, we introduce a config option which can apply an offset
to the beginning of physical memory, and apply this to the "RAM"
region defined in the linker scripts.

This also fixes a problem where an extra megabyte was being
added to the size of system RAM.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit is contained in:
Andrew Boie 2020-06-17 12:20:17 -07:00 • committed by Carles Cufí
commit 87dd0492db
9 changed files with 38 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

7
soc/x86/ia32/linker.ld
View file

@ -22,10 +22,13 @@
#define PHYS_RAM_ADDR DT_REG_ADDR(DT_CHOSEN(zephyr_sram))
#define PHYS_RAM_SIZE DT_REG_SIZE(DT_CHOSEN(zephyr_sram))
#define KERNEL_BASE_ADDR (PHYS_RAM_ADDR + CONFIG_X86_KERNEL_OFFSET)
#define KERNEL_RAM_SIZE (PHYS_RAM_SIZE - CONFIG_X86_KERNEL_OFFSET)
#ifdef CONFIG_XIP
#define PHYS_LOAD_ADDR DT_REG_ADDR(DT_CHOSEN(zephyr_flash))
#else /* !CONFIG_XIP */
#define PHYS_LOAD_ADDR PHYS_RAM_ADDR
#define PHYS_LOAD_ADDR KERNEL_BASE_ADDR
#endif /* CONFIG_XIP */
MEMORY
@ -33,7 +36,7 @@ MEMORY
#ifdef CONFIG_XIP
ROM (rx) : ORIGIN = PHYS_LOAD_ADDR, LENGTH = DT_REG_SIZE(DT_CHOSEN(zephyr_flash))
#endif /* CONFIG_XIP */
RAM (wx) : ORIGIN = PHYS_RAM_ADDR, LENGTH = PHYS_RAM_SIZE
RAM (wx) : ORIGIN = KERNEL_BASE_ADDR, LENGTH = KERNEL_RAM_SIZE
/*
* It doesn't matter where this region goes as it is stripped from the