RE: [ECOS] Memory layout

["Agarwal, Lomesh" <lomesh.agarwal@intel.com>]

Actually I copied and pasted the wrong file.
My rom.ldi file is as follows:
MEMORY
{
    ram  : ORIGIN = 0x00000000, LENGTH = 0x10000000
    rom  : ORIGIN = 0x00000000, LENGTH = 0x01000000
}

SECTIONS
{
    SECTIONS_BEGIN
    SECTION_rom_vectors (ram, 0x00000000, LMA_EQ_VMA)   // vector page gets
remapped from ROM to RAM
    SECTION_text (ram, 0x00002000, LMA_EQ_VMA)
    SECTION_fini (rom, ALIGN (0x4), LMA_EQ_VMA)
    SECTION_rodata (rom, ALIGN (0x4), LMA_EQ_VMA)
    SECTION_rodata1 (rom, ALIGN (0x4), LMA_EQ_VMA)
    SECTION_fixup (rom, ALIGN (0x4), LMA_EQ_VMA)
    SECTION_gcc_except_table (rom, ALIGN (0x4), LMA_EQ_VMA)
    SECTION_fixed_vectors (rom, 0x20, LMA_EQ_VMA)
    SECTION_data (ram, 0xA000, FOLLOWING (.gcc_except_table))
    SECTION_bss (ram, ALIGN (0x4), LMA_EQ_VMA)
    CYG_LABEL_DEFN(__heap1) = ALIGN (0x8);
//    CYG_LABEL_DEFN(__pci_window) = 0xf00000; . =
CYG_LABEL_DEFN(__pci_window) + 0x100000;
    SECTIONS_END
}
So, is this correct if on my platform during boot Flash is aliased at 0 and
after unaliasing flash my DRAM is at 0 address.

Thanks,
Lomesh

-----Original Message-----
From: Jonathan Larmour [mailto:jlarmour@redhat.com] 
Sent: Wednesday, April 10, 2002 1:51 PM
To: Agarwal, Lomesh
Cc: eCos Discuss
Subject: Re: [ECOS] Memory layout


"Agarwal, Lomesh" wrote:
> 
> I want to burn RedBoot in a flash. I should use "ROM" start type. Right?

Yes.

> On my platform during boot Flash is aliased at 0 and after unaliasing
flash
> my DRAM is at 0 address. I have modified the rom.ldi file as follows:
> 
> MEMORY
> {
>     ram  : ORIGIN = 0xA0000000, LENGTH = 0x2000000
>     rom  : ORIGIN = 0x00000000, LENGTH = 0x800000
> }

No, the memory layout should reflect the addresses after unaliasing or MMU
mapping. And it's up to the very initial startup code to set up the
unaliasing/remapping without relying on linker defined symbols or
relocations to do it.

Jifl
-- 
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