From 7ef295ea5b412cbaf82f719ccd49efb51296e841 Mon Sep 17 00:00:00 2001 From: Peter Crosthwaite Date: Fri, 4 Mar 2016 11:30:21 +0000 Subject: loader: Add data swap option to load-elf Some CPUs are of an opposite data-endianness to other components in the system. Sometimes elfs have the data sections layed out with this CPU data-endianness accounting for when loaded via the CPU, so byte swaps (relative to other system components) will occur. The leading example, is ARM's BE32 mode, which is is basically LE with address manipulation on half-word and byte accesses to access the hw/byte reversed address. This means that word data is invariant across LE and BE32. This also means that instructions are still LE. The expectation is that the elf will be loaded via the CPU in this endianness scheme, which means the data in the elf is reversed at compile time. As QEMU loads via the system memory directly, rather than the CPU, we need a mechanism to reverse elf data endianness to implement this possibility. Reviewed-by: Peter Maydell Signed-off-by: Peter Crosthwaite Signed-off-by: Peter Maydell --- hw/i386/multiboot.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'hw/i386/multiboot.c') diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c index c4d7d83..9e164e6 100644 --- a/hw/i386/multiboot.c +++ b/hw/i386/multiboot.c @@ -196,7 +196,8 @@ int load_multiboot(FWCfgState *fw_cfg, } kernel_size = load_elf(kernel_filename, NULL, NULL, &elf_entry, - &elf_low, &elf_high, 0, I386_ELF_MACHINE, 0); + &elf_low, &elf_high, 0, I386_ELF_MACHINE, + 0, 0); if (kernel_size < 0) { fprintf(stderr, "Error while loading elf kernel\n"); exit(1); -- cgit v1.1