How does the CPU communicate with the GPU before drivers are loaded?
As I understand it, GPUs have their own instruction sets, whose instructions are generated by the graphics drivers. The GPU instructions are then sent to the GPU. So, how does graphics communication work before the drivers are loaded? Are there some base instructions which GPUs must implement as a minimum to ensure that the computer can perform basic display tasks?
drivers graphics-card gpu
asked 3 hours ago
VortixDevVortixDev
490415
add a comment |
As I understand it, GPUs have their own instruction sets, whose instructions are generated by the graphics drivers. The GPU instructions are then sent to the GPU. So, how does graphics communication work before the drivers are loaded? Are there some base instructions which GPUs must implement as a minimum to ensure that the computer can perform basic display tasks?
drivers graphics-card gpu
asked 3 hours ago
VortixDevVortixDev
490415
add a comment |
As I understand it, GPUs have their own instruction sets, whose instructions are generated by the graphics drivers. The GPU instructions are then sent to the GPU. So, how does graphics communication work before the drivers are loaded? Are there some base instructions which GPUs must implement as a minimum to ensure that the computer can perform basic display tasks?
drivers graphics-card gpu
asked 3 hours ago
VortixDevVortixDev
490415
As I understand it, GPUs have their own instruction sets, whose instructions are generated by the graphics drivers. The GPU instructions are then sent to the GPU. So, how does graphics communication work before the drivers are loaded? Are there some base instructions which GPUs must implement as a minimum to ensure that the computer can perform basic display tasks?
drivers graphics-card gpu
drivers graphics-card gpu
asked 3 hours ago
VortixDevVortixDev
490415
asked 3 hours ago
VortixDevVortixDev
490415
asked 3 hours ago
VortixDevVortixDev
490415
asked 3 hours ago
VortixDevVortixDev
490415
asked 3 hours ago
VortixDevVortixDev
490415
490415
add a comment |
add a comment |
1 Answer
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"Are there some base instructions...?" Yes, exactly. All GPUs are required to implement one of several simple interfaces - they're too primitive to be called "instruction sets" - which platform firmware ("BIOS" or "UEFI") and drivers that are included with the OS know how to talk to. The usual choice of "simple interface" these days is "VGA" ("Video Graphics Array"), the register-level interface originally defined for the video cards of that standard. (Now 30+ years old!)
For example, if Device Manager on a Windows system IDs the graphics card as the "Microsoft Basic Video Adapter", the OS was unable to find a specific driver for the card and has loaded the VGA-compatible driver instead.
Well, technically, Windows always loads that driver (so it can display e.g. the boot progress screens), then (fairly late in the boot) identifies and loads the "real" driver for your graphics card.
The VGA standard only supports a few low-res graphics modes and text modes, and does not involve what I'd call "running programs" or even "instructions" on the GPU. In essence, system firmware or the "base video driver" just puts it into the desired mode and then writes bits to a bitmap; bits in the bitmap directly correspond to pixels on the screen. Any arithmetic that has to be done to draw lines or curves is done in the CPU. Which is a very low-level and slow way to make stuff show up on the screen. But it's enough for displays from, and simple interactions with, the firmware, for OS installations and early boot-progress screens, etc.
Wikipedia: Video Graphics Array
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
add a comment |
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1 Answer
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1 Answer
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oldest
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"Are there some base instructions...?" Yes, exactly. All GPUs are required to implement one of several simple interfaces - they're too primitive to be called "instruction sets" - which platform firmware ("BIOS" or "UEFI") and drivers that are included with the OS know how to talk to. The usual choice of "simple interface" these days is "VGA" ("Video Graphics Array"), the register-level interface originally defined for the video cards of that standard. (Now 30+ years old!)
For example, if Device Manager on a Windows system IDs the graphics card as the "Microsoft Basic Video Adapter", the OS was unable to find a specific driver for the card and has loaded the VGA-compatible driver instead.
Well, technically, Windows always loads that driver (so it can display e.g. the boot progress screens), then (fairly late in the boot) identifies and loads the "real" driver for your graphics card.
The VGA standard only supports a few low-res graphics modes and text modes, and does not involve what I'd call "running programs" or even "instructions" on the GPU. In essence, system firmware or the "base video driver" just puts it into the desired mode and then writes bits to a bitmap; bits in the bitmap directly correspond to pixels on the screen. Any arithmetic that has to be done to draw lines or curves is done in the CPU. Which is a very low-level and slow way to make stuff show up on the screen. But it's enough for displays from, and simple interactions with, the firmware, for OS installations and early boot-progress screens, etc.
Wikipedia: Video Graphics Array
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
add a comment |
"Are there some base instructions...?" Yes, exactly. All GPUs are required to implement one of several simple interfaces - they're too primitive to be called "instruction sets" - which platform firmware ("BIOS" or "UEFI") and drivers that are included with the OS know how to talk to. The usual choice of "simple interface" these days is "VGA" ("Video Graphics Array"), the register-level interface originally defined for the video cards of that standard. (Now 30+ years old!)
For example, if Device Manager on a Windows system IDs the graphics card as the "Microsoft Basic Video Adapter", the OS was unable to find a specific driver for the card and has loaded the VGA-compatible driver instead.
Well, technically, Windows always loads that driver (so it can display e.g. the boot progress screens), then (fairly late in the boot) identifies and loads the "real" driver for your graphics card.
The VGA standard only supports a few low-res graphics modes and text modes, and does not involve what I'd call "running programs" or even "instructions" on the GPU. In essence, system firmware or the "base video driver" just puts it into the desired mode and then writes bits to a bitmap; bits in the bitmap directly correspond to pixels on the screen. Any arithmetic that has to be done to draw lines or curves is done in the CPU. Which is a very low-level and slow way to make stuff show up on the screen. But it's enough for displays from, and simple interactions with, the firmware, for OS installations and early boot-progress screens, etc.
Wikipedia: Video Graphics Array
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
add a comment |
"Are there some base instructions...?" Yes, exactly. All GPUs are required to implement one of several simple interfaces - they're too primitive to be called "instruction sets" - which platform firmware ("BIOS" or "UEFI") and drivers that are included with the OS know how to talk to. The usual choice of "simple interface" these days is "VGA" ("Video Graphics Array"), the register-level interface originally defined for the video cards of that standard. (Now 30+ years old!)
For example, if Device Manager on a Windows system IDs the graphics card as the "Microsoft Basic Video Adapter", the OS was unable to find a specific driver for the card and has loaded the VGA-compatible driver instead.
Well, technically, Windows always loads that driver (so it can display e.g. the boot progress screens), then (fairly late in the boot) identifies and loads the "real" driver for your graphics card.
The VGA standard only supports a few low-res graphics modes and text modes, and does not involve what I'd call "running programs" or even "instructions" on the GPU. In essence, system firmware or the "base video driver" just puts it into the desired mode and then writes bits to a bitmap; bits in the bitmap directly correspond to pixels on the screen. Any arithmetic that has to be done to draw lines or curves is done in the CPU. Which is a very low-level and slow way to make stuff show up on the screen. But it's enough for displays from, and simple interactions with, the firmware, for OS installations and early boot-progress screens, etc.
Wikipedia: Video Graphics Array
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
"Are there some base instructions...?" Yes, exactly. All GPUs are required to implement one of several simple interfaces - they're too primitive to be called "instruction sets" - which platform firmware ("BIOS" or "UEFI") and drivers that are included with the OS know how to talk to. The usual choice of "simple interface" these days is "VGA" ("Video Graphics Array"), the register-level interface originally defined for the video cards of that standard. (Now 30+ years old!)
For example, if Device Manager on a Windows system IDs the graphics card as the "Microsoft Basic Video Adapter", the OS was unable to find a specific driver for the card and has loaded the VGA-compatible driver instead.
Well, technically, Windows always loads that driver (so it can display e.g. the boot progress screens), then (fairly late in the boot) identifies and loads the "real" driver for your graphics card.
The VGA standard only supports a few low-res graphics modes and text modes, and does not involve what I'd call "running programs" or even "instructions" on the GPU. In essence, system firmware or the "base video driver" just puts it into the desired mode and then writes bits to a bitmap; bits in the bitmap directly correspond to pixels on the screen. Any arithmetic that has to be done to draw lines or curves is done in the CPU. Which is a very low-level and slow way to make stuff show up on the screen. But it's enough for displays from, and simple interactions with, the firmware, for OS installations and early boot-progress screens, etc.
Wikipedia: Video Graphics Array
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
edited 2 hours ago
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
answered 3 hours ago
Jamie HanrahanJamie Hanrahan
18k34078
18k34078
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
add a comment |
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
I'm pretty sure that the "basic graphics" mode in modern windows is more than just VGA. VGA was limited to 640x480 in 16 colors (or a much lower resolution in 256 colors)
– plugwash
53 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
The full situation is complicated. The very first "VGA" cards were indeed that limited. For a long time Windows NT required support for 800x600, but yes, just 16 colors. It looked pretty terrible! See the Wikipedia article I linked.
– Jamie Hanrahan
36 mins ago
add a comment |
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