iosys_map_memcpy_from(9)

💖 iosys_map_memcpy_from — Kernel API Manual ✨

okay so bestie, welcome to the iosys_map_memcpy_from(9) page, straight out of the Kernel API Manual. this one's a little copy helper and it's honestly kind of iconic once you get what it's doing. let's get into it 🫶

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🌸 NAME 🌸

iosys_map_memcpy_from — memcpy from an iosys_map into system memory. that's the whole vibe. 💅

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✨ SYNOPSIS ✨

void iosys_map_memcpy_from (void *dst , const struct iosys_map *src ,
       size_t src_offset , size_t len );

look at that signature, no cap. four args, one job. 🔥

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🎀 ARGUMENTS 🎀

• dst — the destination buffer, and it lives in system memory. that's where the data ends up, bestie.
• src — the iosys_map structure itself. this is where we're copying from 💜
• src_offset — the offset you start copying from. like, where in the map do we begin? 🙈
• len — the number of bytes in src. yes, it's literally byte-counting time ⭐

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🦋 DESCRIPTION 🦋

so here's the tea: it copies data <highpink>from</highpink> an iosys_map, but with an offset applied — which is why src_offset exists. the destination buffer, dst, is chillin' in system memory.

and depending on where the mapping happens to be located, the helper picks the correct method of accessing that memory for you. so you don't have to think about it — it just knows. main character energy, fr fr 👑

ngl, this is one of those helpers where the whole point is that you don't care about the underlying mapping. let the helper handle the vibe check 💅

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🌈 SEE ALSO 🌈

bestie, there is a whole family here and we are listing every single one of them, no skipping:

• Kernel file ./include/linux/iosys-map.h overview(9)
• struct iosys_map(9)
• IOSYS_MAP_INIT_VADDR(9)
• IOSYS_MAP_INIT_VADDR_IOMEM(9)
• IOSYS_MAP_INIT_OFFSET(9)
• iosys_map_set_vaddr(9)
• iosys_map_set_vaddr_iomem(9)
• iosys_map_is_equal(9)
• iosys_map_is_null(9)
• iosys_map_is_set(9)
• iosys_map_clear(9)
• iosys_map_memcpy_to(9)
• iosys_map_incr(9)
• iosys_map_memset(9)
• iosys_map_rd(9)
• iosys_map_wr(9)
• iosys_map_rd_field(9)
• iosys_map_wr_field(9)

like I said. a whole family. go read up, iykyk 💖

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and that's the page!! this came from ./include/linux, dated October 2026, under the title iosys_map_memcpy_from(9) — mwah, thanks for reading, ily, go copy some bytes responsibly 🧚‍♀️💜