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Kernel/Graphics: Don't use [[gnu::packed]] on Bochs VGA structs

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The `[[gnu::packed]]` attribute apparently lowered the required
alignment of the structs, which caused the compiler to generate two
1 byte loads/stores on RISC-V. This caused the kernel to read/write
incorrect values, as the device only seems to accept 2 byte operations.
This commit is contained in:
Sönke Holz 2023-12-10 18:25:54 +01:00 committed by Andrew Kaster
parent dd391d5e8c
commit 78419e858d
1 changed files with 6 additions and 3 deletions
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9
Kernel/Devices/GPU/Bochs/Definitions.h
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@ -37,7 +37,7 @@ enum class BochsDISPIRegisters {
VIDEO_RAM_64K_CHUNKS_COUNT = 0xA,
};
struct [[gnu::packed]] DISPIInterface {
struct DISPIInterface {
u16 index_id;
u16 xres;
u16 yres;
@ -50,13 +50,15 @@ struct [[gnu::packed]] DISPIInterface {
u16 y_offset;
u16 vram_64k_chunks_count;
};
static_assert(AssertSize<DISPIInterface, 22>());
struct [[gnu::packed]] ExtensionRegisters {
struct ExtensionRegisters {
u32 region_size;
u32 framebuffer_byteorder;
};
static_assert(AssertSize<ExtensionRegisters, 8>());
struct [[gnu::packed]] BochsDisplayMMIORegisters {
struct BochsDisplayMMIORegisters {
u8 edid_data[0x400];
u16 vga_ioports[0x10];
u8 reserved[0xE0];
@ -64,5 +66,6 @@ struct [[gnu::packed]] BochsDisplayMMIORegisters {
u8 reserved2[0x100 - sizeof(DISPIInterface)];
ExtensionRegisters extension_regs;
};
static_assert(AssertSize<BochsDisplayMMIORegisters, 1544>());
}