47 lines
1.7 KiB
Plaintext
47 lines
1.7 KiB
Plaintext
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MEMORY
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{
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/*
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* Low 64 KB — reserved for DMA-visible static memory (descriptors and
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* packet buffers). Anything that the EMAC DMA must read or write MUST
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* land here, never in the high RAM region. Apply via the .dma_bss
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* section (see SECTIONS below) plus `#[link_section = ".dma_bss"]`.
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*/
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RAM_DMA : ORIGIN = 0x4FF40000, LENGTH = 0x00010000
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/*
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* Main RAM for code/rodata/data/non-DMA bss/heap/stack. Stops at
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* 0x4FF80000 — the upper 256 KB (0x4FF80000..0x4FFC0000) is the *backing
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* SRAM for the L2 cache* and addresses there behave unpredictably for
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* arbitrary access (writes can be silently dropped, reads return cache
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* tag content, etc.). Stack lives at the top of REGION_STACK so it must
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* not cross 0x4FF80000 either — keeping LENGTH at 0x30000 caps the top
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* exactly there.
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*
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* If `.text` no longer fits, build with `[profile.dev] opt-level = "s"`
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* at the workspace root.
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*/
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RAM : ORIGIN = 0x4FF50000, LENGTH = 0x00030000
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}
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REGION_ALIAS("REGION_TEXT", RAM);
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REGION_ALIAS("REGION_RODATA", RAM);
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REGION_ALIAS("REGION_DATA", RAM);
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REGION_ALIAS("REGION_BSS", RAM);
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REGION_ALIAS("REGION_HEAP", RAM);
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REGION_ALIAS("REGION_STACK", RAM);
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SECTIONS
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{
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/*
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* Note: NOT (NOLOAD). Rust statics carry their initial bytes via the ELF
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* — marking the section NOLOAD would leave DMA_RESOURCES uninitialized at
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* runtime (memory contents are whatever pre-existed) and Rust would run
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* over a struct it thinks is zero-initialized but isn't. Loading the
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* zeros via the ELF image takes a few extra KB but is correct.
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*/
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.dma_bss : ALIGN(128)
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{
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KEEP(*(.dma_bss .dma_bss.*))
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} > RAM_DMA
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}
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