sysadmin/ipxe
1
0
Fork 0
mirror of https://github.com/ipxe/ipxe synced 2025-12-09 20:09:53 +03:00
Code Issues Packages Projects Releases Wiki Activity

[fdtmem] Limit relocation to 32-bit address space

Browse Source 
Devices with only 32-bit DMA addressing are relatively common even on
systems with 64-bit CPUs.  Limit relocation of iPXE to 32-bit address
space so that I/O buffers and other DMA allocations will be accessible
by 32-bit devices.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2025-06-11 13:48:12 +01:00
parent c4a3d438e6
commit 3e8909cf5f
1 changed files with 16 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/core/fdtmem.c
View File

@@ -62,6 +62,9 @@ struct used_region fdtmem_used __used_region = {
/** Maximum accessible physical address */ /** Maximum accessible physical address */
static physaddr_t fdtmem_max; static physaddr_t fdtmem_max;
/** Maximum 32-bit physical address */
#define FDTMEM_MAX32 0xffffffff
/** /**
* Update memory region descriptor based on device tree node * Update memory region descriptor based on device tree node
* *
@@ -249,9 +252,9 @@ static size_t fdtmem_len ( struct fdt *fdt ) {
* @v max Maximum accessible physical address * @v max Maximum accessible physical address
* @ret new New physical address for relocation * @ret new New physical address for relocation
* *
* Find a suitably aligned address towards the top of existent memory * Find a suitably aligned address towards the top of existent 32-bit
* to which iPXE may be relocated, along with a copy of the system * memory to which iPXE may be relocated, along with a copy of the
* device tree. * system device tree.
* *
* This function may be called very early in initialisation, before * This function may be called very early in initialisation, before
* .data is writable or .bss has been zeroed. Neither this function * .data is writable or .bss has been zeroed. Neither this function
@@ -289,6 +292,16 @@ physaddr_t fdtmem_relocate ( struct fdt_header *hdr, physaddr_t max ) {
DBGC ( hdr, "FDTMEM requires %#zx + %#zx => %#zx bytes for " DBGC ( hdr, "FDTMEM requires %#zx + %#zx => %#zx bytes for "
"relocation\n", memsz, fdt.len, len ); "relocation\n", memsz, fdt.len, len );
/* Limit relocation to 32-bit address space
*
* Devices with only 32-bit DMA addressing are relatively
* common even on systems with 64-bit CPUs. Limit relocation
* of iPXE to 32-bit address space so that I/O buffers and
* other DMA allocations will be accessible by 32-bit devices.
*/
if ( max > FDTMEM_MAX32 )
max = FDTMEM_MAX32;
/* Construct memory map and choose a relocation address */ /* Construct memory map and choose a relocation address */
new = old; new = old;
for ( addr = 0, next = 1 ; next ; addr = next ) { for ( addr = 0, next = 1 ; next ; addr = next ) {