xemu/pc-bios/optionrom/multiboot_dma.S
Marcus Hähnel 48972f8cad optionrom: add a DMA-enabled multiboot ROM
Add a new option rom for the multiboot loader, using DMA transfers to copy
data instead of "rep insb".

This significantly lowers QEMU's startup latency by a factor of about 40,
for example, going from 30sec to 0.8sec when loading modules of 120MB
in size.

Signed-off-by: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
Signed-off-by: Adam Lackorzynski <adam@l4re.org>
[Modified to keep the non-DMA code depending on #ifdef USE_FW_CFG_DMA;
 do not write below stack. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-02 15:57:27 +01:00

3 lines
48 B
ArmAsm

#define USE_FW_CFG_DMA 1
#include "multiboot.S"